A microbend test method for measuring the plasticity length scale

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3._Plasticity

Chapter3Plasticity3.1IntroductionUpon being mechanically stressed,a material will,in general, exhibit the following sequence of responses:elastic deformation, plastic deformation,and fracture.This chapter addresses the second response:plastic deformation.A sound knowledge of plasticity is of great importance because:1.Many projects are executed in which small plastic deformationsof the structure are accepted.The‘‘theory of limit design”is used in applications where the weight factor is critical,such as space vehicles and rockets.The rationale for accepting a limited plastic deformation is that the material will work-harden at that region, and plastic deformation will cease once theﬂow stress(due to work-hardening)reaches the applied stress.2.It is very important to know the stresses and strains involved indeformation processing,such as rolling,forging,extrusion,draw-ing,and so on.All these processes involve substantial plastic defor-mation,and the response of the material will depend on its plastic behavior during the processes.The application of plasticity theory to such processes is presented later in this chapter.3.The mechanism of fracture can involve plastic deformation at thetip of a crack.The way in which the high stresses that develop at the crack can be accommodated by the surrounding material is of utmost importance in the propagation of the crack.A mate-rial in which plastic deformation can take place at the crack is‘‘tough,”while one in which there is no such deformation is ‘‘brittle.”4.The stress at which plastic deformation starts is dependent uponthe stress state.A material can have a much greater strength when it is conﬁned--that is,when it is not allowed toﬂow laterally--than when it is not conﬁned.This will be discussed in detail later.A number of criteria for plastic deformation and fracture will beexamined in this chapter.161162PL AS T IC IT Y(a)(b)(c)(d)(e)(g)(f)SPECIMEN 3.1Common tests used todetermine the monotonic strengthof metals.(a)Uniaxial tensile test.(b)Upsetting test.(c)Three-pointbending test.(d)Plane-straintensile test.(e)Plane-straincompression (Ford)test.(f)T orsion test.(g)Biaxial test.The mechanical strength of a material under a steadily increasingload can be determined in uniaxial tensile tests,compression (upset-ting)tests,bend tests,shear tests,plane-strain tensile tests,plane-strain compression (Ford)tests,torsion tests,and biaxial tests.Theuniaxial tensile test consists of extending a specimen whose longitudi-nal dimension is substantially larger than the two lateral dimensions(Figure 3.1(a)).The upsetting test consists of compressing a cylinderbetween parallel platens;the height/diameter ratio has to be lowerthan a critical value in order to eliminate the possibility of instability(buckling)(Figure 3.1(b)).After a certain amount of strain,‘‘barreling”takes place,destroying the state of uniaxial compression.The three-point bend test is one of the most common bending tests.A specimenis simply placed between two supports;a wedge advances and bendsit through its middle point (Figure 3.1(c)).Plane-strain tests simulatethe conditions encountered by a metal in,for instance,rolling.Load-ing is imparted in such a way as to result in zero strain along onedirection.The two most common geometries are shown in Figures3.1(d)and (e).In the tensile mode,two grooves are made parallel toeach other,on opposite sides of a plate.The width of the plate ismuch greater than its thickness in the region of reduced thickness;hence,ﬂow is restricted in the direction of the width.In the com-pressive mode (Ford test),a parallelepiped of metal is machined andinserted between the groove-and-punch setup of Figure 3.1(e).As thetop punch is lowered,the specimen is plastically deformed.Strain isrestricted in one direction.In the torsion test (Figure 3.1(f)),the cylin-drical (or tubular)specimen is subjected to a torque and undergoesan attendant angular displacement.One of the problems in the anal-ysis of the torsion test is that the stress varies as the distance fromthe central axis of the specimen.Accordingly,the biaxial test is usu-ally applied to thin sheets,and one of the conﬁgurations is shown3.2PL AS T I C DE F O R M AT I O N I N T EN SI O N163Fig.3.2A servohydraulicuniversal testing machine linked toa computer.(Courtesy of MTSSystems Corp.)in Figure3.1(g).Other conﬁgurations involve testing a tubular speci-men in tension with an internal pressure and testing a tubular spec-imen in tension with torsion.The results of the tests just describedcan be expressed graphically as stress-versus-strain curves.They can becompared directly by using effective stresses and effective strains.Amachine commonly used to carry out the tests is the so-called univer-sal testing machine.Both screw-driven(Figure2.1)and servohydraulicmachines are very useful for mechanical testing.Figure3.2shows atypical servohydraulic testing machine.3.2Plastic Deformation in T ensionFigure 3.3shows a number of stress--strain curves for the samematerial:AISI1040steel.This might look surprising atﬁrst,butit merely reﬂects the complexity of the microstructural-mechanicalbehavior interactions.Both engineering and true stress--strain curvesare shown.(The deﬁnitions of these are given in Chapter2.)Engi-neering(or nominal)stress is deﬁned as P/A0,while true stress isP/A,where A0and A are the initial and current cross-sectional areas,respectively.Engineering(or nominal)strain is deﬁned as L/L0,whiletrue strain is ln L/L0,where L and L0are the current and initial lengths,164PL AS T IC IT Y3.3Stress–strain curves forAISI 1040steel subjected todifferent heat treatments;curvesobtained from tensile tests.respectively.The yield stress varies from 250to 1,100MPa,dependingon the heat treatment.Conversely,the total strain varies from 0.38to 0.1.The properties of steel are highly dependent upon heat treat-ment,and quenching produces a hard,martensitic structure,whichis gradually softened by tempering treatments at higher temperatures(200,400,and 600◦C).The annealed structure is ductile,but has a lowyield stress.The ultimate tensile stresses (the maximum engineeringstresses)are marked by arrows.After these points,plastic deforma-tion becomes localized (called necking ),and the engineering stressesdrop because of the localized reduction in cross-sectional area.How-ever,the true stress continues to rise because the cross-sectional areadecreases and the material work-hardens in the neck region.Thetrue-stress--true-strain curves are obtained by converting the tensile stress and its corresponding strain into true values and extending thecurve.We know that the volume V is constant in plastic deformation:V =A 0L 0=AL .Consequently,A =A 0L 0L .(3.1)In what follows,we use the subscripts e and t for engineering(nominal)and true stresses and strains,respectively.We haveεe =L −LL 0=A 0A −1,(3.2)σt σe =PA ×A 0P =A 0A =1+εe ,(3.3)σt =(1+εe )σe .(3.4)3.2PL AS T I C DE F O R M AT I O N I N T EN SI O N 165On the other hand,the incremental longitudinal true strain is deﬁnedasd εt =dLL .(3.5)For extended deformations,integration is required:εt = L L 0dL L =ln LL 0,(3.6)exp(εt )=LL 0.(3.7)Substituting Equations 3.2and 3.3into Equation 3.7,we getσt =PA 0exp(εt ).(3.8)Engineering (or nominal)stresses and strains are commonly usedin tensile tests,with the double objective of avoiding complicationsin the computation of σand εand obtaining values that are more sig-niﬁcant from an engineering point of view.Indeed,the load-bearingability of a beam is better described by the engineering stress,referredto the initial area A 0.It ispossible to correlate engineering and truevalues.From Equations 3.4and 3.8,the following relationship isobtained:εt =ln(1+εe )(3.9)Fig.3.4Idealized shapes ofuniaxial stress–strain curve.(a)Perfectly plastic.(b)Idealelastoplastic.(c)Ideal elastoplasticwith linear work-hardening.(d)Parabolic work-hardening (σ=σo +K εn ).All of the preceding curves,as well as other ones,are representedschematically by simple equations in various ways.Figure 3.4showsfour different idealized shapes for stress--strain curves.Note that theseare true-stress--true-strain curves.When we have a large amount ofplastic deformation,the plastic strain is large with respect to theelastic strain,and the latter can be neglected.If the material doesnot work-harden,the plastic curve is horizontal,and the idealizedbehavior is called perfectly plastic.This is shown in Figure 3.4(a).Ifthe plastic deformation is not so large,the elastic portion of thecurve cannot be neglected,and one has an ideal elastoplastic mate-rial (Figure 3.4(b)).A further approximation to the behavior of realmaterials is the ideal elastoplastic behavior depicted in Figure 3.4(c);this is a linear curve with two slopes E 1and E 2that represent thematerial’s elastic and plastic behavior,respectively.One could repre-sent the behavior of the steels in Figure 3.3fairly well by this elasto-plastic,linear work-hardening behavior.It can be seen that E 2 E 1.For example,for annealed steel,E 2∼=70MPa,while E 1=210GPa.However,a better representation of the work-hardening behavior is obtained by assuming a gradual decrease in the slope of the curve as plastic deformation proceeds (shown in Figure 3.4(d)).The convex166PL AS T IC IT Yshape of the curve is well represented by an equation of thetypeσ=Kεn,(3.10)where n<1.This response is usually called‘‘parabolic”hardening,and one can translate it upward by assuming a yield stressσ0,so thatEquation3.10becomesσ=σ0+Kεn,(3.11)The exponent n is called the work-hardening coefﬁcient.These equations that describe the stress--strain curve of a poly-crystalline metal are known as the Ludwik--Hollomon equations.1Inthem,K is a constant,and the exponent n depends on the nature ofthe material,the temperature at which it is work-hardened,and thestrain.The exponent n generally varies between0.2and0.5,while thevalue of K varies between G/100and G/1,000,G being the shear modu-lus.In Equation3.11εis the true plastic strain,while in Equation3.10εis true total strain.Equations3.11and3.10describe parabolic behav-ior.However,such a description is valid only in a narrow stretch of thestress--strain curve.There are two reasons for this.First,the equationspredict a slope of inﬁnity forε=0,which does not conform with theexperimental facts.Second,the equations imply thatσ→∝whenε→∝.But we know that this is not correct and that,experimentally,a saturation of stress occurs at higher strains.Voce2introduced a much different equation,σs−σσs−σ0=exp−εεc,(3.12)whereσs,σ0,andεc are empirical parameters that depend on the material,the temperature,and the strain rate.This equation says that the stress exponentially reaches an asymptotic value ofσs at higher strain values.Furthermore,it gives aﬁnite slope to the stress--strain curve atε=0orσ=σ0.It should be noted that the parameters in the preceding equations (3.10--3.12)depend on the choice of the initial stress and/or strain.For instance,if one prestrained a material,one would affect K in the Ludwik--Hollomon equation.The fact that some equations reasonably approximate the stress--strain curves does not imply that they are capable of describing the curves in a physically satisfactory way.There are two reasons for this: (1)In the different positions of stress--strain curves,different micro-scopic processes predominate.(2)Plastic deformation is a complex1See P.Ludwik,Elemente der Technologischen Mechanik(Berlin:Springer,1909),p.32;and J.H.Hollomon,Trans.AIME,162(1945)268.2E.Voce,J.Inst.Met.,74(1948)537.3.2PL AS T I C DE F O R M AT I O N I N T EN SI O N167 physical process that depends on the path taken;it is not a thermo-dynamic state function.That is to say,the accumulated plastic defor-mation is not uniquely related to the dislocation structure of thematerial.This being so,it is not very likely that simple expressionscould be derived for the stress--strain curves in which the parameterswould have deﬁnite physical signiﬁcance.Some alloys,such as stainless steels,undergo martensitic phasetransformations induced by plastic strain.This type of transformationalters the stress--strain curve.(See Chapter11).Other alloys undergomechanical twinning beyond a threshold stress(or strain),whichaffects the shape of the curve.In these cases,it is necessary to dividethe plastic regime into stages.It is often useful to plot the slope ofthe stress--strain curve vs.stress(or strain)to reveal changes in mech-anism more clearly.In spite of its limitations,the Ludwik--Hollomon Equation3.11isthe most common representation of plastic response.When n=0,itrepresents ideal plastic behavior(no work-hardening).More generalforms of this equation,incorporating both strain rate and thermaleffects,are often used to represent the response of metals;in thatcase they are called constitutive equations.As will be shown in Chap-ter4,theﬂow stress of metals increases with increasing strain rateand decreasing temperature,because thermally activated dislocationmotion is inhibited.The Johnson-Cook equationσ=(σ0+Kεn)1+C ln˙ε˙ε01−T−T rT m−T rm(3.13)is widely used in large-scale deformation codes.The three groups ofterms in parentheses represent work-hardening,strain rate,and ther-mal effects,respectively.The constants K,n,C,and m are materialparameters,and T r is the reference temperature,T m the melting point,and˙ε0the reference strain rate.There are additional equations that incorporate the microstructural elements such as grain size and dis-location interactions and dynamics:they are therefore called‘‘phys-ically based.”The most common ones are the Zerilli--armstrong3andthe MTS(materials threshold stress,developed at Los Alamos NationalLaboratory)equations.The basic idea is to develop one equation thatrepresents the mechanical response of a material from0K to0.5T mand from very low strain rates(∼10−5s−1)to very high strain rates(∼105s−1).Nevertheless,three factors throw monkey wrenches intothese equations:creep(see Chapter13),fatigue(Chapter14),and envi-ronmental effects.The effects of these factors are very complex andcannot be simply‘‘plugged into”the equations.3See F.Zerilli and R.W.Armstrong,J.Appl.Phys.,68(1990)1580.168PL AS T IC IT YExample 3.1For the stress--strain curve shown in Figure E3.1.1(tantalum tested atstrain rate of 10−4s −1),obtain the parameters of the Ludwik--Hollomonequation.Estimate the duration of the test in seconds.70060050040030020010000.050.100.150.200.250.35True strainT ru es tre ss ,MP a 0.300Solution :From the σ−εcurve,we haveσ0=160MPa .We use the Ludwik--Hollomon equationσ−σ0=K εn ,so thatlog(σ−σ0)=log K +n log ε,which is a linear equation.We then make a plot of log (σ−σ0)vs logε(shown in Figure E3.1.2)from the following table of values:σεlog(σ–σ0)log ε2800.05 2.08–1.33450.1 2.27–13850.15 2.35–0.824150.2 2.41–0.704350.25 2.44–0.604550.3 2.47–0.52From the new plot,we havelog K =2.05,K =112,n =slope ≈0.5.Substituting K and n into the Ludwik--Hollomon equation yieldsσ=160+112ε0.5(in MPa).3.2PL AS T I C DE F O R M AT I O N I N T EN SI O N 16932.82.62.42.22−1.4−1.2−1−0.8−0.6−0.4−0.20log elo g(s-s)The duration of the test,given that˙ε=10−4s −1=d εdt ≈ εt ,ist = ε˙ε≈.3310−4=3.3×103s .The volume of a material is assumed to be constant in plasticdeformation.It is known that such is not the case in elastic defor-mation.As was shown in Section ,the constancy in volume impliesthatε11+ε22+ε33=0orε1+ε2+ε3=0(3.14)and that Poisson’s ratio is 0.5.Figure 3.5shows that this assumptionis reasonable and that νrises from 0.3to 0.5as deformation goesfrom elastic to plastic.However,prior to delving into the plasticity theories,we have toknow,for a complex state of stress,the stress level at which the bodystarts to ﬂow plastically.The methods developed to determine this arecalled flow criteria (See Section 3.7).Figure 3.6shows engineering-andtrue-stress--strain curves for the same hot-rolled AISI 4140steel.In theelastic regime the coincidence is exact,because strains are very small(∼0.5%).From Equation 3.9,we can see that we would have εe ≈εt .As plastic deformation increases,εt and εe become progressively dif-ferent.For εt =0.20(a common value for metals),we have εe =0.221.For this deformation,the true stress is 22.1%higher than the nom-inal one.It can be seen that these differences become greater withincreasing plastic deformation.Another basic difference between the170PL AS T IC ITY0.30.40.50.6True strain T r u e s t r e s s , M N /m 2P o i s s o n ’s r a t i o , n 3.5Schematicrepresentation of the change inPoisson’s ratioas the deformationregime changes from elastic toplastic.Strain Str es s,MP a 3.6T rue-andengineering-stress–strain curvesfor AISI 4140hot-rolled steel.R.A.is reduction in area.E n g i n e e r i ng st r e s sEngineering strain (a)E ngin eer i n g s tres s Engineering strain(b)3.7Engineering-(or nominal-)stress–strain curves (a)without and (b)with a yieldpoint.two curves is the decrease in the engineering stress beyond a certainvalue of strain (∼0.14in Figure 3.6).This phenomenon is described indetail in Section 3.2.2.3.2.1T ensile Curve ParametersFigure 3.7shows two types of engineering stress--strain curves.Theﬁrst does not exhibit a yield point,while the second does.Manyparameters are used to describe the various features of these curves.First,there is the elastic limit.Since it is difﬁcult to determine themaximum stress for which there is no permanent deformation,the0.2%offset yield stress (point A in the ﬁgure)is commonly usedinstead;it corresponds to a permanent strain of 0.2%after unload-ing.Actually,there is evidence of dislocation activity in a specimenat stress levels as low as 25%of the yield stress.The region between25and 100%of the yield stress is called the microyield region and hasbeen the object of careful investigations.In case there is a drop inyield,an upper (B )and a lower (C )yield point are deﬁned in Fig.3.7(b).The lower yield point depends on the machine stiffness.A propor-tional limit is also sometimes deﬁned (D);it corresponds to the stressat which the curve deviates from linearity.The maximum engineeringstress is called the ultimate tensile stress (UTS);it corresponds to pointD in Figure 3.7.Beyond the UTS,the engineering stress drops untilthe rupture stress (E )is reached.The uniform strain (F )corresponds tothe plastic strain that takes place uniformly in the specimen.Beyondthat point,necking occurs.Necking is treated in detail in Section3.2.2.G is the strain-to-failure .Additional parameters can be obtainedfrom the stress--strain curve:(1)The elastic energy absorbed by thespecimen (the area under the elastic portion of the curve)is calledresilience ;(2)the total energy absorbed by the specimen during defor-mation,up to fracture (the area under the whole curve),is called workof fracture .The strain rate undergone by the specimen,˙εe =d εe /dt ,isequal to the crosshead velocity,divided by the initial length L 0of thespecimen.The reduction in area is deﬁned as q =A 0−A f A 0,(3.15)where A 0and A f are the initial area and cross-sectional area in the fracture region,respectively.The true strain at the fracture is deﬁned as εf =ln A 0A f .(3.16)The true uniform strain is εu =ln A 0A u ,(3.17)where A u is the cross-sectional area corresponding to the onset of necking (when the stress is equal to the UTS).3.2.2NeckingNecking corresponds to the part of the tensile test in which instabilityexists.The neck is a localized region in the reduced section of thespecimen in which the greatest portion of strain concentrates.Thespecimen ‘‘necks”down in this region.Figure 3.8shows the onsetof necking in a tensile specimen;arrows show the region where thecross-section starts to decrease.Several criteria for necking have been developed.The oldest oneis due to Considere.4According to Considere,necking starts at themaximum stress (UTS),when the increase in strength of the materialdue to work-hardening is less than the decrease in the loadbearingability due to the decrease in cross-sectional area.In other words,necking starts when the increase in stress due to the reduction incross-sectional area starts to exceed the increase in load-bearing abil-ity due to work-hardening.We have,at the onset of necking,d σed εe =0(3.18)Substituting Equations 3.4and 3.9into 3.18yields d σt 1+εe d (e εt −1)=d σte εtd (e εt −1)=0.Fig.3.8T ensile specimen beingtested;arrows show onset ofnecking.Making the transformation of variablese εt −1=Z ,e εt =Z +1yieldsd σt Z +1 d Z =σt d (Z +1)−1d Z +(Z +1)−1d σtd Z =0,−σt (Z +1)−2+(Z +1)−1d σtd Z =0,4A.Considère,Ann.Ponts.Chaussèes ,Ser.6.(1885)574.Strain, %W o rkha rdening,d σ/dε,G P a Fig.3.9Log d σ/d εversus log εfor stainless steel AISI 302.(Adapted with permission from A.S.de S.e Silva and S.N.Monteiro,Metalurgia-ABM ,33(1977)417.)or−σt e −2εt +e −εt =d σtd (e εt −1)=0,d σtd (e εt −1)=σt e −εt ,(3.19)d σtσt =e −εt d (e εt −1)=d εt .Using Equation 3.10,we obtaind σt =nK εn −1d εtand it follows from Equation 3.19that σt =nK εn −1.Finally,applyingEquation 3.10again results in K εn =nK εn −1,so thatεu =n .This is an important result.The work-hardening coefﬁcient is numer-ically equal to the true uniform strain and can be easily obtained inthis way.It is sometimes useful to present results of tensile tests in plots ofd σ/d εversus σor d σ/d εversus ε.An example of a plot of log (d σ/d ε)versus log εfor AISI 302stainless steel is given in Figure 3.9.It canbe seen that d σ/d εdecreases with ε,indicating that the necking ten-dency steadily increases.For metals that do not exhibit any work-hardening capability,necking should start immediately at the onsetof plastic ﬂow.Under certain conditions (predeformation at very lowtemperature or very high strain rate)some metals can exhibit thisresponse,called work-softening .The formation of the neck results in an accelerated and localizeddecrease in the cross-sectional area.Figure 3.6shows how the true-stress--true-strain curve continues to rise after the onset of necking.Itcan also be seen that the true strain at fracture is much higher thanthe ‘‘total strain.”The correct plotting of the true-stress--true-straincurve beyond the UTS requires determination of the cross-sectionalarea in the neck region continuously after necking.This is difﬁcultto do,and the simplest way is to obtain one single point on theplot,joining it to the point corresponding to the maximum load.For this reason,a dashed line is used in Figure3.6.The deformation in the neck region is much higher than the one uniformly distributed in the specimen.It can be said that the neck acts as a second ten-sile specimen.Since its length is smaller than that of the specimen, and the crosshead velocity is constant,the strain rate is necessarily higher.The onset of necking is accompanied by the establishment of a tri-axial state of stress in the neck;the uniaxial stress state is destroyed by the geometrical irregularity.After studyingﬂow criteria(see Section 3.7),we will readily see that theﬂow stress of a material is strongly dependent on the state of stress.Hence,a correction has to be intro-duced to convert the triaxialﬂow stress into a uniaxial one.If we imagine an elemental cube aligned with the tensile axis and situ-ated in the neck region,it can be seen that it is subjected to tensile stresses along three directions.(The external boundaries of the neck generate the tensile components perpendicular to the axis of the spec-imen.)The magnitude of the transverse tensile stresses depends on the geometry of the neck,the material,the shape of the specimen, the strain-rate sensitivity of the material,the temperature,the pres-sure,and so on.Bridgman5introduced a correction from a stress analysis in the neck.His analysis applies to cylindrical specimens. The equation that expresses the corrected stress isσ=σav(1+2R/r n)ln(1+r n/2R),(3.20)where R is the radius of curvature of the neck and r n is the radius of the cross-section in the thinnest part of the neck.Thus,one has to continuously monitor the changes in R and r n during the test to perform the correction.Figure3.10presents a plot in which the corrections have already been computed as a function of strain beyond necking.There are three curves,for copper,steel,and aluminum.The correction factor can be read directly from the plot shown.εu is the true uniform strain(the strain at onset of necking).In Figure3.6,the true-stress--true-strain curve that was corrected for necking by the Bridgman technique lies slightly below the one determined strictly from the reduction in area at fracture and the load at the breaking point.This is consistent with Figure3.10;σis always lower thanσav.Necking is a characteristic of tensile stresses;compressive stresses are not characterized by necking.Barreling is the corresponding devi-ation from the uniaxial state in compressive tests.Hence,metals will exhibit necking during deformation processing only if the state of stress is conducive to it(tensile).Figure3.11shows plainly how the work-hardening capacity of a metal greatly exceeds that in an individ-ual tensile test.Wire was drawn to different strains:Drawing the wire 5P.W.Bridgman,Trans.ASM,32(1974)553.0.80.91.00.200.40.60.8 1.0 1.2CopperSteelAluminium/avIn e ss – u 3.10Correction factor fornecking as a function of strain inneck,ln(A 0/A ),minus strain atnecking,εu .(Adapted withpermission from W .J.McGregorT egart,Elements of MechanicalMetallurgy (New Y ork:MacMillan,1964),p.22.)150010005000.0 1.0 2.0 3.0 4.0 5.0 6.07.08.09.0True strainT ruestr ess ,MN/m 2Fe –0.003% C3.11Stress–strain curves for Fe–0.003%C alloy wire,deformed to increasingstrains by drawing;each curve is started at the strain corresponding to the priorwire-drawing reduction.(Courtesy of H.J.Rack)consists of pulling it through a conical die;at each pass,there is areduction in cross section.Tensile tests were conducted after differentdegrees of straining (0to 7.4)by wire drawing;it can be seen that thewire work hardens at each step.However,the individual tensile testsare interrupted by necking and fracture.In wire drawing,neckingand fracture are inhibited by the state of stress in the deformationzone (compressive).The individual true-stress--true-strain curves werecorrected for necking by Bridgman’s technique;in each case,the indi-vidual curve ﬁts fairly well into the overall work-hardening curve.Itcan be concluded that the individual tensile test gives only a very。

ASTM E562-02Standard Test Method for Determining Volume Fraction by Systematic Manual Point Count1

Designation:E562–02Standard Test Method forDetermining Volume Fraction by Systematic Manual Point Count1This standard is issued under theﬁxed designation E562;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.INTRODUCTIONThis test method may be used to determine the volume fraction of constituents in an opaque specimen using a polished,planar cross section by the manual point count procedure.1.Scope1.1This test method describes a systematic manual point counting procedure for statistically estimating the volume fraction of an identiﬁable constituent or phase from sections through the microstructure by means of a point grid.1.2The use of automatic image analysis to determine the volume fraction of constituents is described in Practice E1245.1.3This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1ASTM Standards:E3Guide for Preparation of Metallographic Specimens2 E7Terminology Relating to Metallography2E407Practice for Microetching Metals and Alloys2E691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3E1245Practice for Determining the Inclusion or Second Phase Constituent Content of Metals by Automatic Image Analysis23.Terminology3.1Deﬁnitions—For deﬁnitions of terms used in this prac-tice,see Terminology E7.3.2Deﬁnitions of Terms Speciﬁc to This Standard:3.2.1point count—the total number of points in a test grid that fall within the microstructural feature of interest,or on the feature boundary;for the latter,each test point on the boundary is one half a point.3.2.2point fraction—the ratio,usually expressed as a per-centage,of the point count of the phase or constituent of interest on the two-dimensional image of an opaque specimen to the number of grid points,which is averaged over nﬁelds to produce an unbiased estimate of the volume fraction of the phase or constituent.3.2.3stereology—the methods developed to obtain informa-tion about the three-dimensional characteristics of microstruc-tures based upon measurements made on two-dimensional sections through a solid material or their projection on a surface.3.2.4test grid—a transparent sheet or eyepiece reticle witha regular pattern of lines or crosses that is superimposed over the microstructural image for counting microstructural features of interest.3.2.5volume fraction—the total volume of a phase or constituent per unit volume of specimen,generally expressed as a percentage.3.3Symbols:P T=total number of points in the test grid.P i=point count on the i thﬁeld.P P(i)=P iP T3100=percentage of grid points,in theconstituent observed on the i thﬁeld.n=number ofﬁelds counted.P¯p=1n(i51nP p~i!=arithmetic average of P p(i).s=estimate of the standard deviation(s)(see(Eq3)in Section10).1This practice is under the jurisdiction of ASTM Committee E04on Metallog-raphy and is the direct responsibility of Subcommittee E04.14on QuantitativeMetallography.Current edition approved April10,2002.Published June10,2002.Originallypublished as E562–st previous edition E562–01.2Annual Book of ASTM Standards,V ol03.01.3Annual Book of ASTM Standards,V ol14.02.1Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.95%CI=95%conﬁdence interval=6t s/=n(see Note1).t=a multiplier related to the number ofﬁelds examined and used in conjunction with thestandard deviation of the measurements to de-termine the95%CI.V V=volume fraction of the constituent or phase expressed as a percentage(see(Eq5)in Section10).%RA=%relative accuracy,a measure of the statistical precision=(95%CI/P¯p)3100.N OTE1—Table1gives the appropriate multiplying factors(t)for any number ofﬁelds measured.4.Summary of Test Method4.1A clear plastic test grid or eyepiece reticle with a regular array of test points is superimposed over the image,or a projection of the image,produced by a light microscope, scanning electron microscope,or micrograph,and the number of test points falling within the phase or constituent of interest are counted and divided by the total number of grid points yielding a point fraction,usually expressed as a percentage,for thatﬁeld.The average point fraction for n measuredﬁelds gives an estimate of the volume fraction of the constituent.This method is applicable only to bulk opaque planar sections viewed with reﬂected light or electrons.5.Signiﬁcance and Use5.1This test method is based upon the stereological prin-ciple that a grid with a number of regularly arrayed points, when systematically placed over an image of a two-dimensional section through the microstructure,can provide, after a representative number of placements on differentﬁelds, an unbiased statistical estimation of the volume fraction of an identiﬁable constituent or phase(1,2,3).45.2This test method has been described(4)as being superior to other manual methods with regard to effort,bias, and simplicity.5.3Any number of clearly distinguishable constituents or phases within a microstructure(or macrostructure)can be counted using the method.Thus,the method can be applied to any type of solid material from which adequate two-dimensional sections can be prepared and observed.5.4A condensed step-by-step guide for using the method is given in Annex A1.6.Apparatus6.1Test Grid,consisting of a speciﬁed number of equally spaced points formed by the intersection of very thin lines.Two common types of grids(circular or square array)are shown in Fig.1.6.1.1The test grid can be in the form of a transparent sheet that is superimposed upon the viewing screen for the measure-ment.6.1.2Eyepiece Reticle,may be used to superimpose a test grid upon the image.6.2Light Microscope,or other suitable device with a viewing screen at least100mm3125mm,preferably with graduated x and y stage translation controls,should be used to image the microstructure.6.3Scanning Electron Microscope,may also be used to image the microstructure;however,relief due to polishing or heavy etching must be minimized or bias will be introduced as a result of deviation from a true two-dimensional section through the microstructure.6.4Micrographs,of properly prepared opaque specimens, taken with any suitable imaging device,may be used provided theﬁelds are selected without bias and in sufficient quantity to properly sample the microstructure.6.4.1The applicable point counting grid shall only be applied once to each micrograph.Point counting measurements should be completed on differentﬁelds of view and,therefore, different micrographs.Repeated point count measurements on an individual micrograph is not allowed.6.4.2The magniﬁcation of the micrograph should be as high as needed to adequately resolve the microstructure without resulting in adjacent grid points overlaying a single constituent feature.7.Sample Selection7.1Samples selected for measurement of the phase or constituent should be representative of the general microstruc-ture,or of the microstructure at a speciﬁed location within a lot, heat,or part.7.2A description of the sample locations should be included as a part of the results.7.3Any orientation of the prepared section(that is,whether longitudinal or transverse)can be used.However,it should be recorded since it may have an effect upon the precision obtained.7.4If the sample microstructure contains gradients or inho-mogeneities(for example,banding)then the section should contain or show the gradient or inhomogeneity.8.Sample Preparation8.1The two-dimensional sections should be prepared using standard metallographic,ceramographic,or other polishing procedures,such as described in Methods E3.4The boldface numbers in parentheses refer to the list of references at the end of this standard.TABLE195%Conﬁdence Interval Multipliers No.of Fields n t No.of Fields n t5 2.77619 2.1016 2.57120 2.0937 2.44721 2.0868 2.36522 2.0809 2.30623 2.07410 2.26224 2.06911 2.22825 2.06412 2.20126 2.06013 2.17927 2.05614 2.16028 2.05215 2.14529 2.04816 2.13130 2.04517 2.12040 2.02018 2.11060 2.000`1.9608.2Smearing or other distortions of the phases or constitu-ents during preparation of the section or sections should be minimized because they tend to introduce an unknown bias into the statistical volume fraction estimate.8.3Etching of the sections,as described in Test Methods E 407,should be as shallow (that is,light)as possible because deviations from a planar two-dimensional section will cause a bias toward over estimation of the volume fraction.8.4Stain-or coloring-type etchants are preferable to those that cause attack of one or more of the constituents or phases.8.5Description of the etchant and etching procedure should be included in the report.8.6If etching is used to provide contrast or distinguishabil-ity of constituents then the volume fraction estimates should be obtained as a function of etching time to check the signiﬁcance of any bias introduced.9.Procedure 9.1Principle :9.1.1An array of points formed by a grid of lines or curves is superimposed upon a magniﬁed image (that is,a ﬁeld of view)of a metallographic specimen.9.1.2The number of points falling within the microstruc-tural constituent of interest is counted and averaged for a selected number of ﬁelds.9.1.3This average number of points expressed as a percent-age of the total number of points in the array (P T )is an unbiased statistical estimation of the volume percent of the microstructural constituent of interest.9.1.4A condensed step-by-step description of the procedure is provided in Annex A1.9.2Grid Selection :9.2.1The grid should consist of equally spaced points formed by the intersection of ﬁne lines.Diagrams of two possible grids,one with a circular pattern and one with a square pattern,which are recommended for use,are shown in Fig.1.9.2.2Determine the number of points (that is,the grid size,P T )from a visual estimate of the area fraction occupied by the constituent of interest.Table 2provides guidelines for this selection.The values in Table 2do not correspond to theoreti-cal constraints;but,by using these values,empirical observa-tions have shown that the method is optimized for a given precision.9.2.2.1The user may choose to employ a 100point grid over the entire range of volume fractions.The use of 100–point grid facilitates easy volume percent calculations.the use of only one overlay or eyepiece reticle for all volume percent determinations may save both time and money.9.2.2.2For constituents present in amount of less than 2%,a 400–point grid may be used.9.2.3Superimpose the grid,in the form of a transparency,upon a ground glass screen on which the section image is projected.9.2.4A grid in the form of an eyepiece reticle may also be used.9.2.5If the constituent areas form a regular or periodic pattern on the section image,avoid the use of a grid having a similarpattern.CircularGridSquare GridN OTE 1—The entire 24points can be used,or the outer 16,or the inner 8points.FIG.1Examples of Possible Grid Conﬁgurations That Can BeUtilizedTABLE 2Guidelines for Grid Size Selection AN OTE 1—A grid size selection which gives a signiﬁcant number of ﬁelds having no grid points on the constituent of interest should be avoided.Visual Area Fraction Estimate Expressed as a PercentageGrid Size (Number of Points,P T )2to 5%1005to 10%4910to 20%25>20%16AThese guidelines represent an optimum for efficiency for the time spent counting and for the statistical information obtained per gridplacement.9.3Magniﬁcation Selection :9.3.1Select the magniﬁcation so that it is as high as needed to clearly resolve the microstructure without causing adjacent grid points to fall over the same constituent feature.9.3.2As a guideline,choose a magniﬁcation that gives an average constituent size that is approximately one half of the grid spacing.9.3.3As the magniﬁcation is increased,the ﬁeld area decreases,and the ﬁeld-to-ﬁeld variability increases,thus requiring a greater number of ﬁelds to obtain the same degree of measurement precision.9.4Counting :9.4.1Count and record for each ﬁeld the number of points falling on the constituent of interest.9.4.2Count any points falling on the constituent boundary as one half.9.4.3In order to minimize bias,any point that is doubtful as to whether it is inside or outside of the constituent boundary should be counted as one half.9.4.4P P ~i !5P i 3100P T(1)9.4.5The values of P P(i)are used to calculate P¯p and standard deviation,s .9.5Selection of the Number of Fields :9.5.1The number of ﬁelds or images to measure depends on the desired degree of precision for the measurement.Table 3gives a guide to the number of ﬁelds or images to be counted as a function of P T ,the selected relative accuracy (statistical precision),and the magnitude of the volume fraction.9.6Selection of the Array of Fields :9.6.1Use a uniformly spaced array of ﬁelds to obtain the estimated value,P p ,and the estimated standard deviation,s .9.6.2If gradients or inhomogeneities are present,then a uniform spacing of ﬁelds may introduce a bias into the estimate.If another method of ﬁeld selection is used,for example,random,then describe it in the report.9.6.3When the microstructure shows a certain periodicity of distribution of the constituent or phase being measured,any coincidence of the points of the grid and the structure must beavoided.This can be achieved by using either a circular grid or a square grid placed at an angle to the microstructural periodicity.9.7Grid Positioning Over Fields —Make grid positioning of each ﬁeld without viewing the microstructure to eliminate any possibility of operator bias.This can be accomplished by moving the x and y stage mechanism a ﬁxed amount while shifting to the next ﬁeld without looking at the microstructure.9.8Improving Measurement Precision —It is recommended that the user attempt to sample more of the microstructure either by multiple specimens or by completely repeating the metallographic preparation on the same sample when the precision for a single set of data is not acceptable (see Section 11).10.Calculation of the Volume Percentage Estimate and%Relative Accuracy 10.1The average percentage of grid points on the features of interest provides an unbiased statistical estimator for the volume percentage within the three dimensional microstruc-ture.The value of the multiplier,t ,can be found in Table 1.Thus,the average,P¯p ,the standard deviation estimator,s ,and the 95%conﬁdence interval,95%CI,should be calculated and recorded for each set of ﬁelds.The equations for calculat-ing these values are as follows:P ¯p 51n (i 51nP p ~i !(2)s 5F 1n 21(i 51n[P p ~i !2P¯p G21/2(3)95%CI 5t 3s=n(4)10.2The volume percentage estimate is given as:V v 5P¯p 695%CI (5)10.3An estimate of the %relative accuracy associated withthe estimate can be obtained as:%RA 595%CIP¯p 3100(6)TABLE 3Prediction of the Number of Fields (n )to be Observed as a Function of the Desired Relative Accuracy and of the EstimatedMagnitude of the Volume Fraction of the ConstituentAmount of volume fraction,V v in percent33%Relative Accuracy20%Relative Accuracy10%Relative AccuracyNumber of ﬁelds n for a grid of P T =Number of ﬁelds n for a grid of P T =Number of ﬁelds n for a grid of P T =16points 25points 49points 100points 16points 25points 49points 100points 16points 25points 49points 100points 2110753520310200105501,2508004102005503015812580402050032016580102515104654020102501608540201510543020105125804020N OTE 1—The given values in the table above are based on the formula:n .4E 2·1002V vVV where:E =0.013%RA,and V V =is expressed in%.10.3.1Estimates for the number ofﬁelds required to obtain a%relative accuracy of10,20,or33%with different volume percentages and grid sizes are provided in Table3.These values were calculated under the assumption that the features have a random distribution upon the metallographic section.10.4The%relative accuracy reported should always be calculated from the sample data and should not be taken from Table3.11.Improving the Volume Fraction Estimate11.1If additionalﬁelds are measured to reduce the% relative accuracy,then the following rule gives an excellent guideline:To reduce the%RA by50%,then a total of four times the original number ofﬁelds should be measured. 11.2When additionalﬁelds are selected on the same sec-tion,they should not overlap the initial set but mayﬁt between ﬁelds of the initial set,and should also form a systematic sampling array.11.3As an example,if a6by5array ofﬁelds was used to obtain the initial set,then by halving the spacing and measur-ing the intermediateﬁeld positions,a total of four times the number ofﬁelds can be measured.Hence,120totalﬁelds would be measured by halving the spacing(in both x and y directions)and measuring the intermediate positions to form a 12by10array.This additional effort should reduce the conﬁdence interval,and thus the%RA,by approximately 50%.11.4Where additionalﬁelds are measured on the same section,the average,P¯p,the standard deviation estimate,s,the 95%conﬁdence interval,95%CI,and the%relative accu-racy,%RA,should be calculated using the increased total number ofﬁelds as a single data set.11.5If additional sections are prepared from the same sample by completely repeating the sample preparation,or if additional samples are prepared,then the same procedure should be used for each section,and the data recorded and reported separately.A grand average can be calculated by taking the average of the set means in this case.If no sample heterogeneity is indicated(that is,the conﬁdence intervals about the mean of each set overlap),then the95%CI can be calculated from the standard deviation obtained using the data from all of the sets(that is,pooling the data and calculating a mean,standard deviation,and95%CI).11.6Where the95%CI do not overlap for the different sets, then a statistically signiﬁcant difference between samples or sections may be present.In this case,more rigorous statistical signiﬁcance tests should be considered.12.Report12.1Report the following information:12.1.1Raw data,12.1.2Estimated volume%(P¯p)695%CI,12.1.3%relative accuracy(calculated value,not one esti-mated from Table2),12.1.4Number ofﬁelds per metallographic section,12.1.5Number of sections,12.1.6Sample description and preparation,including etchant,if used,12.1.7Section orientation,12.1.8Magniﬁcation,12.1.9Grid description,12.1.10Field array description and spacing,and12.1.11List of volume%estimates for each metallographic section695%CI.13.Effort Required13.1A reasonable estimate for the time required to perform the manual point count on30ﬁelds for a single type of microstructural feature is30min.This time estimate can probably be decreased to15min after some experience and familiarity with the point counting procedure and the micro-structure analyzed are obtained.14.Precision and Bias514.1The systematic point count technique is the most efficient manual technique for development of an unbiased estimate of the volume fraction of an identiﬁable constituent or phase.14.2The presence of periodicity,structural gradients or inhomogeneities in the section can inﬂuence the precision and accuracy of the volume fraction estimate.Guidelines are given in7.4,9.2.5,9.6.2,9.6.3,11.5and11.6.14.3The quality of the sample preparation can inﬂuence precision and accuracy of the volume fraction estimate.Guide-lines are given in Section8.14.4The point density of the grid used to make the volume fraction estimate can inﬂuence the efficiency,precision and relative accuracy of the volume fraction estimate.Guidelines are given in9.2.14.5The magniﬁcation employed in the point count can inﬂuence precision and relative accuracy.Guidelines are given in9.3.14.6The counting of grid points at a constituent boundary, particularly when doubt exists as to their exact location, presents an opportunity for bias in the estimate of the volume fraction.Guidelines are given in9.4.2,and9.4.3.14.7The number ofﬁelds measured,the method ofﬁeld selection and their spacing will inﬂuence the precision and relative accuracy of the volume fraction estimate.Guidelines are given in9.5,and9.6.14.8The precision of a given measurement of the volume fraction is determined by calculation of the standard deviation, 95%conﬁdence interval,and%relative accuracy as described in Section10.14.9If a greater degree of precision and relative accuracy is required,follow the guidelines in Section11.14.10Results from a round-robin interlaboratory program (5),where three micrographs with different constituent volume fractions were point counted using two different grids(25and 100points)by33different operators,were analyzed5in accordance with Practice E691to develop repeatability and reproducibility standard deviations and95%conﬁdence limits (see Table4).For the same number of random grid placements (10)on each micrograph,the repeatability and reproducibility standard deviations and95%conﬁdence intervals increased 5Support data are available from ASTM Headquarters.RequestRR:E04-1003.with increasing P¯p for measurements with the 25point test grid but were essentially constant for the 100point test grid.Note that the interlaboratory %relative accuracies (which are muchpoorer than those for the individual operators)improve as P¯p increases and as the grid point density (P T )increases.The 100point grid,with four times the number of grid points,decreasedthe relative accuracies by about 21to 51%as P¯p increased (Micrographs A to C).ANNEX(Mandatory Information)A1.PROCEDURE FOR SYSTEMATIC MANUAL POINT COUNTA1.1Visually estimate area percent of constituent or feature of interest on metallographic section.A1.2Using Table 3,select grid size,P T .A1.3Superimpose the grid upon the microscope viewing screen and select magniﬁcation such that the size of the features of interest are approximately one half of the spacing between grid points.A1.4Select a statistical precision,(%RA)for example,10,20,or 33%,desired for the measurement.Note that the %RA is deﬁned as follows:%RA 595%CIP¯p 3100A1.5Using Table 3,obtain an estimate of the number of ﬁelds,n ,required to obtain the desired degree of precision.N OTE A1.1—A minimum of 30ﬁelds must be measured in order to calculate the 95%conﬁdence interval using the equation given in A1.12.A1.6Determine the spacing between ﬁelds that will form a systematic (equally spaced)array covering a majority of the sample area without overlap.A1.6.1For example,on a 10mm 315mm specimen area where 40ﬁelds are indicated from Table 3,a 5by 8array of ﬁelds at 1.5mm intervals might be used.A1.7Determine the number of turns required on the stagetranslation knobs to move the stage from one ﬁeld position to the next.Do not observe the image while translating to a new ﬁeld to avoid bias in positioning the grid.A1.8Count and record the number of grid points,P i ,falling within the features of interest.N OTE A1.2—Any point that falls on the boundary should be counted as one half.To avoid bias,questionable points should be counted as one half.A1.9Calculate the average %of points per ﬁeld,P¯p ,and its standard deviation,s .N OTE A1.3—A hand calculator with a (+key can be used to calculate these quantities.A1.10The average percentage of points is:P ¯p 51n (i 51n P p ~i !51n (i 51nP i /P TA1.11The standard deviation estimate is:s 5F 1n 21(i 51n [P p ~i !2P¯p G21/2A1.12The 95%conﬁdence interval for P¯p is:95%CI 5ts=nTABLE 4Results of Interlaboratory Point Counting Round-Robin 5MicrographP ¯p (%)Repeatability Std.Dev.(%)Reproducibility Std.Dev.(%)Repeatability 95%CI (%)Reproducibility95%CI (%)Repeatability%RAReproducibility%RA25Point Test Grid A 9.9 5.3 5.314.814.8149.5149.5B 17.8 6.6 6.918.619.4104.5109.0C 27.08.89.424.726.291.597.0100Point Test Grid A 9.3 3.9 3.911.011.0118.3118.3B 15.9 3.4 4.09.411.259.170.4C25.13.94.310.912.143.448.2REFERENCES(1)DeHoff,R.T.,and Rhines, F.N.,eds.,Quantitative Microscopy,McGraw-Hill Book Co.,New York,NY,1968.(2)Underwood,E.E.,Quantitative Stereology,Addison-Wesley Publish-ing Co.,Reading,MA,1970.(3)Howard,R.T.,and Cohen,M.,“Quantitative Metallography byPoint-Counting and Lineal Analysis,”Transactions AIME,V ol172, 1947,pp.413–426.(4)Hilliard,J.E.,and Cahn,J.W.,“An Evaluation of Procedures inQuantitative Metallography for V olume-Fraction Analysis,”Transac-tions AIME,V ol221,1961,pp.344–352.(5)Abrams,H.,“Practical Applications of Quantitative Metallography,”Stereology and Quantitative Metallography,ASTM STP504,ASTM, Philadelphia,PA,1972,pp.138–182.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this ers of this standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed everyﬁve years and if not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,at the address shown below.This standard is copyrighted by ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959, United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at610-832-9585(phone),610-832-9555(fax),or service@(e-mail);or through the ASTM website().。

ASTM+D+4065-2001

1 This practice is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. Current edition approved September 10, 2001. Published November 2001. Originally published as D 4065 – 82. Last previous edition D 4065 – 95.
3
2
*A Summary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1. Scope* 1.1 This practice is for general use in gathering and reporting dynamic mechanical data. It incorporates laboratory practice for determining dynamic mechanical properties of specimens subjected to various oscillatory deformations on a variety of instruments of the type commonly called dynamic mechanical analyzers or dynamic thermomechanical analyzers. 1.2 This practice is intended to provide means of determining the transition temperatures, elastic, and loss moduli of plastics over a range of temperatures, frequencies, or time, by free vibration and resonant or nonresonant forced vibration techniques. Plots of elastic and loss moduli are indicative of the viscoelastic characteristics of a plastic. These moduli are functions of temperature or frequency in plastics, and change rapidly at particular temperatures or frequencies. The regions of rapid moduli change are normally referred to as transition regions. 1.3 The practice is primarily useful when conducted over a range of temperatures from −160°C to polymer degradation and is valid for frequencies from 0.01 to 1000 Hz. 1.4 This practice is intended for materials that have an elastic modulus in the range from 0.5 MPa to 100 GPa (73 psi to 1.5 3 107 psi). 1.5 Apparent discrepancies may arise in results obtained under differing experimental conditions. Without changing the observed data, reporting in full (as described in this practice) the conditions under which the data were obtained will enable apparent differences observed in another study to be reconciled. 1.6 Test data obtained by this practice are relevant and appropriate for use in engineering design. 1.7 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the

ASTM D883–00 塑料制品的术语

Designation:D883–00Standard Terminology Relating toPlastics1This standard is issued under theﬁxed designation D883;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1This terminology covers deﬁnitions of technical terms used in the plastics industry.Terms that are generally under-stood or adequately deﬁned in other readily available sources are not included.1.2When a term is used in an ASTM document for which Committee D20is responsible it is included only when judged, after review,by Subcommittee D20.92to be a generally usable term.1.3Deﬁnitions that are identical to those published by another standards body are identiﬁed with the abbreviation of the name of the organization;for example,IUPAC is the International Union of Pure and Applied Chemistry.1.4A deﬁnition is a single sentence with additional infor-mation included in discussion notes.It is reviewed every5 years;the year of last review is appended.1.5For literature related to plastics terminology,see Appen-dix X1.2.Referenced Documents2.1ASTM Standards:C162Terminology of Glass and Glass Products2D638Test Method for Tensile Properties of Plastics3D747Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam3D790Test Methods for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulating Materi-als3D882Test Methods for Tensile Properties of Thin Plastic Sheeting3D907Terminology of Adhesives4D1003Test Method for Haze and Luminous Transmittance of Transparent Plastics3D1566Terminology Relating to Rubber5D4703Practice for Compression Molding ThermoplasticMaterials into Test Specimens,Plaques,or Sheets6E308Practice for Computing the Colors of Objects by Using the CIE System73.Terminology3.1Deﬁnitions:A-stage,n—an early stage in the preparation of certain thermosetting resins in which the material is still soluble in certain liquids,and may be liquid or capable of becoming liquid upon heating.D ISCUSSION—Sometimes referred to as Resol.(See also B-stage andC-stage.)(1978)8acetal plastics,n—plastics based on polymers having a predominance of acetal linkages in the main chain.(See also polyoxymethylene.)(1985)acrylic plastics—plastics based on polymers made with acrylic acid or a structural derivative of acrylic acid.(1982) addition polymerization—polymerization in which mono-mers are linked together without the splitting off of water or other simple molecules.(1983)adiabatic extrusion—a method of extrusion in which,after the extrusion apparatus has been heated sufficiently by conventional means to plastify the material,the extrusion process can be continued with the sole source of heat being the conversion of the drive energy,through viscous resis-tance of the plastic mass in the extruder.(1978)aging,n—(1)the effect on materials of exposure to an environment for an interval of time.(2)the process of exposing materials to an environment for an interval of time. (1973)alkyd plastics—plastics based on alkyd resins.(1980)alkyd resin—a polyester convertible into a crosslinked form; requiring a reactant of functionality higher than two,or having double bonds.(1982)alloy,n(in plastics)—two or more immiscible polymers united,usually by another component,to form a plastic resin having enhanced performance properties.allyl plastics—plastics based on allyl resins.(1978)1This terminology is under the jurisdiction of ASTM Committee D20on Plastics and is the direct responsibility of Subcommittee D20.92on Terminology.Current edition approved Aug.10,2000.Published October2000.Originally published as D883–st previous edition D883–99.2Annual Book of ASTM Standards,V ol15.02.3Annual Book of ASTM Standards,V ol08.01. 4Annual Book of ASTM Standards,V ol15.06. 5Annual Book of ASTM Standards,V ol09.01.6Annual Book of ASTM Standards,V ol08.03.7Annual Book of ASTM Standards,V ol06.01.8Date indicates year of introduction or latest review or revision. 1*A Summary of Changes section appears at the end of this standard. Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.allyl resin—a resin made by polymerization of chemical compounds containing the allyl group.(1978)amino plastics,n—plastics based on amino resins.(1978) amino resin,n—a resin made by polycondensation of a compound containing amino groups,such as urea or melamine,with an aldehyde,such as formaldehyde,or an aldehyde-yielding material.(1985)apparent density—See density,apparent.aromatic polyester,n—a polyester derived from monomers in which all the hydroxyl and carboxyl groups are linked directly to aromatic nuclei.(1986)artiﬁcial weathering—exposure to laboratory conditions, which may be cyclic,involving changes in temperature, relative humidity,radiant energy,and any other elements found in the atmosphere in various geographical areas.D ISCUSSION—The laboratory exposure conditions are usually inten-siﬁed beyond those encountered in actual outdoor exposure in an attempt to achieve an accelerated effect.(1980)average injection velocity,n—the mean value of the velocity of the molten plasticﬂow front within a cavity during the injection time that is calculated from the shot volume and injection time.D ISCUSSION—The average injection velocity is calculated as follows:V av5V st i3A c3nwhere:V av=average injection velocity,mm/s,V s=shot volume,mm3,t i=injection time,s,A c=cross section of the cavity,mm2,andn=number of cavities.This calculation is valid for molds containing a single cavity or those containing identical multi-specimen cavities only and not for family molds.B-stage,n—an intermediate stage in the reaction of certain thermosetting resins in which the material swells when in contact with certain liquids and softens when heated,but may not entirely dissolve or fuse.D ISCUSSION—The resin in an uncured thermosetting molding com-pound is usually,in this stage,sometimes referred to as Resitol.(See also A-stage and C-stage.)(1978)bag modeling—a method of molding or laminating which involves the application ofﬂuid pressure,usually by means of air,steam,water or vacuum,to aﬂexible barrier material which transmits the pressure to the material being molded or bonded.D ISCUSSION—The process is usually employed for forming shapesfrom preformed laminates comprising aﬁbrous sheet impregnated with an A-stage or a B-stage thermosetting resin.(1986)binder,n—in a reinforced plastic,the continuous phase which holds together the reinforcement.D ISCUSSION—During fabrication,the binder,which may be eitherthermoplastic or thermoset,usually undergoes a change in state.(1978) biodegradable plastic,n—See degradable plastic.blister,n—an imperfection,a rounded elevation of the surfaceof a plastic,with boundaries that may be more or less sharply deﬁned,somewhat resembling in shape a blister on the human skin.(1983)block copolymer—an essentially linear copolymer in which there are repeated sequences of polymeric segments of different chemical structure.(1982)blocking,n—unintentional adhesion between plasticﬁlms or between aﬁlm and another surface.(1983)bloom,n—a visible exudation or efflorescence on the surface of a material.(1972)blowing agent—a compounding ingredient used to produce gas by chemical or thermal action,or both,in manufacture of hollow or cellular articles.(1983)blow molding—a method of fabrication in which a heated parison is forced into the shape of a mold cavity by internal gas pressure.(1985)branched polyethylene plastics,n—those containing signiﬁ-cant amounts of both short-chain and long-chain branching and having densities in the0.910to0.940g/cm3range.D ISCUSSION—These plastics,usually produced commercially by freeradical polymerization,are subcategorized by density level;low density polyethylene plastic and medium density polyethylene plastic.bulk density,n—the weight per unit volume of a loosely packed material,such as a molding powder or pellets.D ISCUSSION—This term should not be used synonymously withapparent density.bulk factor,n—the ratio of the volume of a given mass of molding material to its volume in the molded form.D ISCUSSION—The bulk factor is also equal to the ratio of the densityof the material to its apparent density in the unmolded form.(ISO) (1982)bulk molding compound(BMC),n—a putty-like mixture of any thermosetting resin containingﬁllers,ﬁber reinforce-ments,catalysts and thickening agents,or thermoplastic polymers,often extruded into logs or ropes.D ISCUSSION—BMC is suitable for molding by any one of threematched-metal-mold processes—compression molding,transfer mold-ing,or injection molding.(1983)butylene plastics—plastics based on resins made by the polymerization of butene or copolymerization of butene with one or more unsaturated compounds,the butene being in greatest amount by weight.(1975)C-stage,n—theﬁnal stage in the reaction of certain thermo-setting materials in which they have become practically insoluble and infusible.D ISCUSSION—The resin in a fully cured thermoset molding is,in thisstage,sometimes referred to as Resite.(See also A-stage and B-stage.) (1986)castﬁlm—aﬁlm made by depositing a layer of plastic,either molten,in solution,or in a dispersion,onto a surface, solidifying and removing theﬁlm from the surface.(1982) cavity,n—in specimen preparation,the part of the hollow space of a mold that forms one specimen.cell,n—a small cavity surrounded partially or completely by walls.(1983)cell,closed—a cell totally enclosed by its walls and hence not interconnecting with other cells.(ISO)(See cell and cell, open.)(1983)cell,open—a cell not totally enclosed by its walls and hence interconnecting with other cells.(See cell and cell,closed.) (1983)cellular plastic—a plastic containing numerous cells,inten-tionally introduced,interconnecting or not,distributed throughout the mass.(See also syntactic cellular plastics.) (1983)cellular striation,n—a condition characterized by a layer within a cellular material that differs greatly from the characteristic cell structure.cellulosic plastics,n—plastics based on cellulose compounds, such as esters(cellulose acetate)and ethers(ethyl cellulose). (1985)chalking,n—(plastics)a powdery residue on the surface of a material resulting from degradation or migration of an ingredient,or both.D ISCUSSION—Chalking may be designed-in characteristic.(1980) chemically foamed polymeric material—a cellular material in which the cells are formed by gases generated from thermal decomposition or other chemical reaction.(1982) chlorinated poly(vinyl chloride)—a poly(vinyl chloride) (PVC)polymer modiﬁed by additional chlorination.(2000) chlorinated poly(vinyl chloride)plastics—plastics based on chlorinated poly(vinyl chloride)in which the chlorinated poly(vinyl chloride)is in the greatest amount by weight. (1978)chloroﬂuorocarbon plastics—plastics based on polymers made with monomers composed of chlorine,ﬂuorine,and carbon only.(ISO)(1983)chloroﬂuorohydrocarbon plastics,n—plastics based on poly-mers made with monomers composed of chlorine,ﬂuorine, hydrogen,and carbon only.(ISO)(1982)circuit—inﬁlament winding,the winding produced by a single revolution of mandrel or form.(1978)closed-cell cellular plastics—cellular plastics in which almost all the cells are noninterconnecting.(1983)coldﬂow—See creep.(1983)cold molding—a special process of compression molding in which the molding is formed at room temperature and subsequently baked at elevated temperatures.(1982) collapse,n—inadvertent densiﬁcation of cellular material dur-ing manufacture resulting from breakdown of cell structure. (1982)composite,n—a solid product consisting of two or more distinct phases,including a binding material(matrix)and a particulate orﬁbrous material.D ISCUSSION—Examples are moulding material containing reinforcingﬁbers,particulateﬁllers,or hollow spheres.(1991) compost—the product of composting.compostable plastic—a plastic that undergoes biological deg-radation during composting to yield carbon dioxide,water, inorganic compounds,and biomass at a rate consistent with other known compostable materials and leaves no visually distinguishable or toxic residues.(1996)compound,n—an intimate admixture of(a)polymer(s)with all the materials necessary for theﬁnished product.(1983) compression molding—the method of molding a material already in a conﬁned cavity by applying pressure and usually heat.(1986)condensation polymer—a polymer made by condensation polymerization.(1983)condensation polymerization—polymerization in which monomers are linked together with the splitting off of water or other simple molecules.(1983)contact pressure molding,n—a method of molding or lami-nating in which the pressure,usually less than70kPa(10 psi),is only slightly more than necessary to hold the materials together during the molding operation.(1985) cooling time,n—in molding,the time interval from the start of forward screw movement until the mold starts to open. copolymer—See polymer.(1983) copolymerization—See polymerization.(1983)crater,n—a small,shallow surface imperfection.(1978) crazing,n—apparentﬁne cracks at or under the surface of a plastic.D ISCUSSION—The crazed areas are composed of polymeric materialof lower density than the surrounding matrix.(1978)creep,n—the time-dependent part of strain resulting from stress.(1983)cross laminate—a laminate in which some of the layers of material are oriented approximately at right angles to the remaining layers with respect to the grain or strongest direction in tension.(See also parallel laminate).(1982) crosslinking,n—the formation of a three dimensional polymer by means of interchain reactions resulting in changes in physical properties.(1983)cross section of the cavity,n—in a mold for test specimens, the area of a planar section perpendicular to theﬂow pattern duringﬁlling of the mold that forms the critical portion of the test specimen.cure,v—to change the properties of a polymeric system into a more stable,usable condition by the use of heat,radiation,or reaction with chemical additives.D ISCUSSION—Cure may be accomplished,for example,by removal ofsolvent or by crosslinking.(ISO)(1983)cure cycle—the schedule of time periods,at speciﬁed condi-tions,to which a reacting thermosetting material is subjected to reach a speciﬁed property level.(1983)cure time—the period of time that a reacting thermosetting material is exposed to speciﬁc conditions to reach a speciﬁed property level.(1983)cut-layers—as applied to laminated plastics,a condition of the surface of machined or ground rods and tubes and of sanded sheets in which cut edges of the surface layer or lower laminations are revealed.(1978)cycle time,n—in molding,the total time used to carry out a complete sequence of operations making up the molding cycle.degradable plastic,n—a plastic designed to undergo a sig-niﬁcant change in its chemical structure underspeciﬁcenvironmental conditions resulting in a loss of some prop-erties that may vary as measured by standard test methods appropriate to the plastic and the application in a period of time that determines its classiﬁcation.(1991) biodegradable plastic,n—a degradable plastic in which the degradation results from the action of naturally-occurring micro-organisms such as bacteria,fungi,and algae.D ISCUSSION—The level of biodegradability may be indicated asshown in subordinate deﬁnitions for biodegradable plastics.(1991) hydrolytically degradable plastic,n—a degradable plastic in which the degradation results from hydrolysis.D ISCUSSION—The level of hydrolytic degradability may be indicatedas shown in subordinate deﬁnitions for hydrolytically degradable plastic.(1991)oxidatively degradable plastic,n—a degradable plastic in which the degradation results from oxidation.D ISCUSSION—The level of oxidative degradability may be indicatedas shown in subordinate deﬁnitions for oxidatively degradable plastic.(1991)photodegradable plastic,n—a degradable plastic in which the degradation results from the action of natural daylight.D ISCUSSION—The level of photodegradability may be indicated asshown in subordinate deﬁnitions for photodegradable plastic.(1991) degradation,n—a deleterious change in the chemical struc-ture,physical properties,or appearance of a plastic.(1980) delamination,n—the separation of the layers of material in a laminate.(1978)density,apparent—the weight in air of a unit volume of a material.D ISCUSSION—This term is sometimes used synonymously with bulkdensity.(1973)density,bulk—the weight per unit volume of a material including voids inherent in material as tested.D ISCUSSION—This term is commonly used for material such asmolding powder.(1973)depth,n—in the case of a beam,the dimension parallel to the direction in which the load is applied.(1978)dome,n—in reinforced plastics,an end of aﬁlament-wound cylindrical container.(1985)dry-blend,n—a dry compound prepared withoutﬂuxing or addition of solvent(also called powder blend).(1983)dry-spot,n—an imperfection in reinforced plastics,an area of incomplete surfaceﬁlm where the reinforcement has not been wetted with resin.(1983)durometer,n—an instrument for measuring indentation hard-ness.elastomer,n—a macromolecular material that at room tem-perature returns rapidly to approximately its initial dimen-sions and shape after substantial deformation by a weak stress and release of the stress.(1985)engineered plastic,n—a material that has been made by speciﬁc design and through use of particular monomers and monomer sequences to produce a plastic with desired properties,possibly for a speciﬁc application.(1991)engineering plastics,n—those plastics and polymeric compo-sitions for which well-deﬁned properties are available such that engineering rather than empirical methods can be used for the design and manufacture of products that require deﬁnite and predictable performance in structural applica-tions over a substantial temperature range.epoxy plastics,n—thermoplastic or thermosetting plastics containing ether or hydroxyalkyl repeating units,or both, resulting from the ring-opening reactions of lower molecular weight polyfunctional oxirane resins,or compounds,with catalysts or with various polyfunctional acidic or basic coreactants.D ISCUSSION—Epoxy plastics often are modiﬁed by the incorporationof diluents,plasticizers,ﬁllers,thixotropic agents,or other materials.(1985)ethylene plastics,n—plastics based on polymers of ethylene or copolymers of ethylene with other monomers,the ethyl-ene being in greatest amount by mass.(ISO)(1982) expandable plastic,n—a plastic in a form capable of being made cellular by thermal,chemical,or mechanical means. (1985)expanded plastics—See cellular plastic.(1985) extrusion,n—a process in which heated or unheated plastic is forced through a shaping oriﬁce(a die)in one continuously formed shape,as inﬁlm,sheet,rod,or tubing.(1983) fabricating,n—the manufacture of plastic products from molded parts,rods,tubes,sheeting,extrusions,or other forms by appropriate operations such as punching,cutting, drilling,and tapping including fastening plastic parts to-gether or to other parts by mechanical devices,adhesives, heat sealing,or other means.(1978)ﬁber show,n—strands or bundles ofﬁbers not covered by resin which are at or above the surface of a reinforced plastic.(1985)ﬁller,n—a relatively inert material added to a plastic to modify its strength,permanence,working properties,or other quali-ties,or to lower costs.(See also reinforced plastic.)(1978)ﬁlm,n—in plastics,an optional term for sheeting having a nominal thickness not greater than0.25mm(0.01in.). (1985)ﬁsh-eye,n—small globular mass that has not blended com-pletely into the surrounding material.See gel.(1978)ﬂuorocarbon plastic,n—a plastic based on polymers made with perﬂuoromonomers.D ISCUSSION—When the monomer is essentially tetraﬂuoroethylene,the preﬁx TFE is sometimes used to designate these materials.It is preferable to use the accepted abbreviation,PTFE.TFE should not be used by itself to mean PTFE.When the resins are copolymers of tetraﬂuoroethylene and hexaﬂuoropropylene,the resins may be desig-nated with the preﬁx FEP.Other preﬁxes may be adopted to designate otherﬂuorocarbon plastics.(ISO)(1983)ﬂuorohydrocarbon plastics,n—plastics based on polymers made with monomers composed ofﬂuorine,hydrogen,and carbon only.(ISO)(1982)ﬂuoroplastic,n—a plastic based on polymers made from monomers containing one or more atoms ofﬂuorine,orcopolymers of such monomers with other monomers,the ﬂuorine-containing monomer(s)being in greatest amount by mass.D ISCUSSION—For speciﬁc examples ofﬂuoroplastic seeﬂuorocarbonplastic,chloroﬂuorocarbon plastics,ﬂuorohydrocarbon plastics, and chloroﬂuorohydrocarbon plastics.(1983)foamed plastics,n—See cellular plastics(the preferred termi-nology).(1983)forming,n—a process in which the shape of plastic pieces such as sheets,rods,or tubes is changed to a desired conﬁguration.D ISCUSSION—The use of the term“forming”in plastics technologydoes not include such operations as molding,casting,or extrusion,in which shapes or pieces are made from molding materials or liquids.(1982)furan plastics—plastics based on furan resins.(ISO)(1982) furan resin,n—a resin in which the furan ring is an integral part of the polymer chain and represents the greatest amount by mass.(ISO)(1983)gate,n—in an injection mold,a constriction in theﬂow channel between the runner and the mold cavity.(1983) gel,n—(1)a semisolid system consisting of a network of solid aggregates in which liquid is held.(2)the initial jelly-like solid phase that develops during the formation of a resin from a liquid.(3)with respect to vinyl plastisols,gel is a state between liquid and solid that occurs in the initial states of heating,or upon prolonged storage.D ISCUSSION—All three types of gels have very low strengths and donotﬂow like a liquid.They are soft,ﬂexible,and may rupture under their own weight unless supported externally.(1978)(4)in plasticﬁlm and sheet,a nodule of plastic material composedof one or more of oxidized,high-molecular-weight,unmelted,non-solvated,or cross-linked material of the same composition as the matrix that,for a variety of reasons,has not blended with the matrix.See ﬁsh-eye.D ISCUSSION—Gel in theﬁlm or sheet is to be distinguished fromcontamination such as particles of dirt,carbon,or lint.(1992)gel point,n—the stage at which a liquid begins to exhibit pseudo-elastic properties.D ISCUSSION—This stage may be detected as the inﬂection point on aviscosity-time plot.(See gel(2).)(1985)gel time,n—the period of time from the initial mixing of the reactants of a liquid material composition to the time when gelation occurs,as deﬁned by a speciﬁc test method.D ISCUSSION—For a material that must be processed by exposure tosome form of energy,the zero time is the start of exposure.(1983) glass,n—an inorganic product of fusion which has cooled to a rigid condition without crystallizing.D ISCUSSION—Term not deﬁned by Committee D20.Deﬁnition ap-proved by Committee C14on Glass and Glass Products.See Termi-nology C162.(a)Glass is typically hard and brittle and has a conchoidal fracture.It may be colorless or colored,and transparent to opaque.Masses or bodies of glass may be made colored,translucent,or opaque by the presence of dissolved,amorphous,or crystalline material.(b)When a speciﬁc kind of glass is indicated,such descriptive termsasﬂint glass,barium glass,and window glass should be used following the basic deﬁnition,but the qualifying term is to be used as understood by trade custom.(c)Objects made of glass are loosely and popularly referred to asglass;such as glass for a tumbler,a barometer,a window,a magniﬁer or a mirror.(1978)glassﬁnish—a material applied to the surface of glassﬁbers used to reinforce plastics and intended to improve the physical properties of such reinforced plastics over that obtained using glass reinforcement withoutﬁnish.(1982) glass transition—the reversible change in an amorphous polymer or in amorphous regions of a partially crystalline polymer from(or to)a viscous or rubbery condition to(or from)a hard and relatively brittle one.D ISCUSSION—The glass transition generally occurs over a relativelynarrow temperature region and is similar to the solidiﬁcation of a liquid to a glassy state;it is not a phase transition.Not only do hardness and brittleness undergo rapid changes in this temperature region but other properties,such as thermal expansibility and speciﬁc heat also change rapidly.This phenomenon has been called second order transition, rubber transition and rubbery transition.The word transformation has also been used instead of transition.Where more than one amorphous transition occurs in a polymer,the one associated with segmental motions of the polymer backbone chain or accompanied by the largest change in properties is usually considered to be the glass transition.(1980)glass transition temperature(Tg)—the approximate mid-point of the temperature range over which the glass transi-tion takes place.D ISCUSSION—The glass transition temperature can be determinedreadily only by observing the temperature at which a signiﬁcant change takes place in a speciﬁc electrical,mechanical,or other physical property.Moreover,the observed temperature can vary signiﬁcantly depending on the speciﬁc property chosen for observation and on details of the experimental technique(for example,rate of heating, frequency).Therefore,the observed Tg should be considered only an estimate.The most reliable estimates are normally obtained from the loss peak observed in dynamic mechanical tests or from dialatometric data.(1978)graft copolymer—a copolymer in which polymeric side chains have been attached to the main chain of a polymer of different structure.(1973)gusset,n—(1)a piece used to give additional size or strength in a particular location of an object.(2)the folded-in portion ofﬂattened tubularﬁlm.(1972) halocarbon plastics—plastics based on resins made by the polymerization of monomers composed only of carbon and a halogen or halogens.(1978)haze—the cloudy or turbid aspect or appearance of an other-wise transparent specimen caused by light scattered from within the specimen or from its surfaces.D ISCUSSION—For the purpose of Test Method D1003,haze is thepercentage of transmitted light which,in passing through the specimen, deviates from the incident beam through forward scatter more than2.5 deg on the average.(1983)heat mark—extremely shallow depression or groove in the surface of a plastic visible because of a sharply deﬁned rim or a roughened surface.(See also shrink mark.)(1978)high density polyethylene plastics,(HDPE)n —those linear polyethylene plastics,g.v.,having a standard density of 0.941g/cm 3or greater.D ISCUSSION —These plastics are usually produced commercially by processes not employing free radical polymerization.Standard density refers to the density of the material molded to a thickness of 1.9mm (0.075in.)using Procedure C of Annex A1of Practice D 4703.high-pressure molding,n —a method of molding or laminat-ing in which the pressure used is greater than 1400kPa (200psi).(1985)hold pressure,n —in molding,the melt pressure during the hold time interval in injection molding.homopolymer,n —a polymer resulting from polymerization involving a single monomer.(1983)hydrocarbon plastics —plastics based on resins made by the polymerization of monomers composed of carbon and hy-drogen only.(1985)hydrolytically degradable plastics,n —See degradable plas-tic.inhibitor,n —a substance used in low concentration which suppresses a chemical reaction.D ISCUSSION —Inhibitors,unlike catalysts,are consumed during the reaction.(1983)injection molding,n —the process of forming a material by forcing it,in a ﬂuid state and under pressure,through a runner system (sprue,runner,gate(s))into the cavity of a closed mold.D ISCUSSION —Screw injection molding and reaction injection molding are types of injection molding.(1983)injection time,n —the time interval from the beginning of screw forward movement until switching over to hold pressure.(1995)insert,n —a part consisting of metal or other material which may be molded into position or may be pressed into the molding after the completion of the molding operation.(ISO)(1978)isotactic,adj —pertaining to a type of polymeric molecular structure containing a sequence of regularly spaced asym-metric atoms arranged in like conﬁguration in a polymer chain.(1985)knit-line,n —See weld-line (the preferred terminology).(1983)knuckle area —in reinforced plastics,the area of transition between sections of different geometry in a ﬁlament-wound part.(1985)laminate,9n —a product made by bonding together two or more layers of material or materials.(See also cross lami-nate and parallel laminate.)(ISO)D ISCUSSION —A single resin-impregnated sheet of paper,fabric,or glass mat,for example,is not considered a laminate.Such a single-sheet construction may be called a “lamina.”(See also reinforced plastic.)(1983)lattice pattern —in reinforced plastics,a pattern of ﬁlamentwinding with a ﬁxed arrangement of open voids.(1985)lay,n —(1)the length of twist produced by stranding ﬁlaments,such as ﬁbers,wires,or roving;(2)the angle that such ﬁlaments make with the axis of the strand during a stranding operation.D ISCUSSION —Length of twist of a ﬁlament is usually measured as the distance parallel to the axis of the strand between successive turns of the ﬁlament.(1985)lay up,n —in reinforced plastics,an assembly of layers of resin-impregnated material ready for processing.(1982)lay up,v —in reinforced plastics,to assemble layers of resin-impregnated material for processing.(1985)let-go,n —an area in laminated glass over which an initial adhesion between interlayer and glass has been lost.(1985)lignin plastics —plastics based on lignin resins.(ISO)(1983)lignin resin —a resin made by heating lignin or by reaction of lignin with chemicals or resins,the lignin being in greatest amount by mass.(ISO)(1983)linear low density polyethylene plastics,(LLDPE)n —those linear polyethylene plastics,q.v.,having a standard density of 0.919to 0.925g/cm 3.D ISCUSSION —These plastics are usually produced commercially by processes not employing free radical polymerization.Standard density refers to the density of the material molded to a thickness of 1.9mm (0.075in.)using Procedure C of Annex A1of Practice D 4703.linear medium density polyethylene plastics,(LMDPE)n —those linear polyethylene plastics,q.v.,having a stan-dard density of 0.926to 0.940g/cm 3.D ISCUSSION —These plastics are usually produced commercially by processes not employing free radical polymerization.Standard density refers to the density of the material molded to a thickness of 1.9mm (0.075in.)using Procedure C of Annex A1of Practice D 4703.linear polyethylene plastics,n —those containing insigniﬁcant amounts of long-chain branching but which may contain signiﬁcant amounts,by design,of short-chain branching.D ISCUSSION —These plastics,usually produced commercially by pro-cesses not employing free radical polymerization,are subcategorized by density level;linear low density polyethylene plastic,linear medium density polyethylene plastic,and high density polyethylene plastic.For differentiation among high molecular versions of these plastics pro-duced commercially by stereo-speciﬁc catalysts,see extra-high mo-lecular weight polyethylene plastic and ultra-high molecular weight polyethylene plastic.low density polyethylene plastics,(LDPE)n —those branched polyethylene plastics,q.v.,having a standard density of 0.910to 0.925g/cm 3.D ISCUSSION —These plastics are usually produced commercially by processes employing free radical polymerization.Standard density refers to the density of the material molded to a thickness of 1.9mm (0.075in.)using Procedure C of Annex A1of Practice D 4703.low-pressure molding,n —a method of molding or laminating in which the pressure is 1400kPa (200psi)or less.(1985)lubricant bloom —See bloom.(1982)luminous transmittance,n —the ratio of the luminous ﬂux transmitted by a body to the ﬂux incident upon it.9These deﬁnitions are identical with those appearing in Terminology D 907,which were prepared by ASTM Committee D14onAdhesives.。

维卡软化点D1525

Designation:D1525–06Standard Test Method forVicat Softening Temperature of Plastics1This standard is issued under theﬁxed designation D1525;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope*1.1This test method covers determination of the tempera-ture at which a speciﬁed needle penetration occurs when specimens are subjected to speciﬁed controlled test conditions.1.2This test method is not recommended for ethyl cellu-lose,nonrigid poly(vinyl chloride),poly(vinylidene chloride), or other materials having a wide Vicat softening range.1.3The values stated in SI units are to be regarded as standard.1.4This standard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.N OTE1—This test method and ISO306:1987(E)are technically equiva-lent,with the exception of the allowance for creep,prior to beginning the test,in this test method.2.Referenced Documents2.1ASTM Standards:2D618Practice for Conditioning Plastics for TestingD883Terminology Relating to PlasticsD1898Practice for Sampling of Plastics3E1Speciﬁcation for ASTM Liquid-in-Glass Thermometers E77Test Method for Inspection and Veriﬁcation of Ther-mometersE220Test Method for Calibration of Thermocouples By Comparison TechniquesE644Test Methods for Testing Industrial Resistance Ther-mometersE691Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test MethodE1137/E1137M Speciﬁcation for Industrial Platinum Re-sistance Thermometers2.2ISO Standards:4ISO306Plastics—Thermoplastic Material—Determination of Vicat Softening Temperature3.Terminology3.1Deﬁnitions—Deﬁnitions of plastics used in this test method are in accordance with those deﬁned in Terminology D883,unless otherwise speciﬁed.3.1.1Vicat softening temperature—the temperature at which aﬂat-ended needle of1-mm2circular cross section will penetrate a thermoplastic specimen to a depth of1mm under a speciﬁed load using a selected uniform rate of temperature rise.4.Summary of Test Method4.1Aﬂat-ended needle loaded with a speciﬁed mass is placed in direct contact with a test specimen.The mass applied can be one of two accepted loads,as follows:Loading1—1060.2NLoading2—5061.0NThe specimen and needle are heated at either of two permis-sible rates,as follows:Rate A—5065°C/hRate B—120610°C/hThe temperature at which the needle has penetrated to a depth of160.01mm is recorded as the Vicat softening temperature.5.Signiﬁcance and Use5.1Data obtained by this test method may be used to compare the heat-softening qualities of thermoplastic materi-als.5.2This test method is useful in the areas of quality control, development,and characterization of plastic materials.6.Apparatus6.1The equipment shall be constructed essentially as shown in Fig.1and shall consist of the following:1This test method is under the jurisdiction of ASTM Committee D20on Plastics and is the direct responsibility of Subcommittee D20.30on Thermal Properties (Section D20.30.07).Current edition approved March15,2006.Published April2006.Originally approved st previous edition approved in2000as D1525-00.2For referenced ASTM standards,visit the ASTM website,,or contact ASTM Customer Service at service@.For Annual Book of ASTM Standards volume information,refer to the standard’s Document Summary page onthe ASTM website.3Withdrawn.4Available from American National Standards Institute(ANSI),25W.43rd St.,4th Floor,New York,NY10036.*A Summary of Changes section appears at the end of this standard.Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.6.1.1Immersion Bath —The bath containing the heat-transfer medium shall be equipped with a stirrer,temperature-measuring device,and heater.The heater shall have automatic control of the selected bath temperature-rise rate (see 4.1).The bath should be constructed to allow the specimens to be submerged at least 35mm below the surface of the heat-transfer medium.6.1.2Heat-Transfer Medium —Several liquids,such as sili-cone oils,glycerine,ethylene glycol,and mineral oil have been used successfully for various plastics.5The medium used shall be free from contaminants and shall have no short-time effect at elevated temperatures on the material being tested,and shall be of low viscosity at room temperature.The results of the test may depend on the thermal diffusivity of the heat-transfer medium.N OTE 2—It is desirable to have a method of cooling the bath in order to reduce the time required to lower the temperature of the bath between tests.This may be accomplished by using a cooling coil installed in the bath or an external heat-transfer system.If the temperature rise rate is adversely affected by the presence of residual coolant in the cooling coils,the coolant should be purged prior to beginning the test.6.1.3Specimen Support —A suitable stand or support for the specimen to be placed in the bath.The vertical members that attach the specimen support to the upper plate shall be made of a material having the same coefficient of expansion as that used for the rod through which the load is applied in order that the penetration-measuring device reading caused by differential expansion over the intended temperature range does not exceed 0.02mm when the specimen is replaced by a piece of heat-resistant material.66.1.4Penetration-Measuring Device —The device used for measuring the penetration of the specimen shall be capable ofmeasuring a penetration depth of at least 160.01mm.The measuring device may be an analog or digital dial gauge or similar device,including an electronic-displacement sensing apparatus.6.1.5Masses —A set of masses of suitable sizes shall be supplied so that the net force on the needle point shall be equal to 1060.2N (Loading 1)or 5061.0N (Loading 2)when the apparatus is assembled.The net force shall consist of the weight of the needle rod assembly,the force attributed to action of the penetration-measuring device,and the extra weight that is required to balance the system.The required mass is calculated as follows:Required mass,m w 5~F 2F s !/9.806652m rF =total force to be applied to the specimen,N,F s=force exerted by any penetration-measuring device,N (this is a positive value if the thrust of the spring is towards the specimen (downward),a negative value if the thrust of the spring is opposing the descent of the rod,or zero if no such device is involved),m r =mass of the needle rod assembly,kg,andm w =extra mass applied to attain the desired force,kg.Veriﬁcation of the load should be made on new equipment and after replacing penetration-measuring devices,or at any time to ensure that the equipment is in calibration.The calibration procedure for dial-gauge-type penetration-measuring devices is described in Appendix X1and Appendix X2.The methods for determination of the thrust contributed by dial-gauge-type penetration-measuring devices are also given in Appendix X1and Appendix X2.6.1.6Temperature-Measuring Device —A thermocouple,re-sistance thermometer (RTD),or thermometer adequate to cover the range being tested.The thermometer shall be one of the following,or its equivalent,in accordance with Speciﬁcation E 1:Thermometer 1C or 2C,having ranges from −20to 150°C5Silicone oils having a room temperature viscosity of 100cP have been found satisfactory and safe for short-term heat cycles up to 260°C.6Borosilicate glass has been found satisfactory for thispurpose.FIG.1Apparatus for Softening TemperatureDeterminationor−5to300°C,respectively,depending on the test range.The thermocouple or resistance thermometer and related electronics shall be accurate to at least60.5°C.Mercury-in-glass ther-mometers shall be calibrated for the depth of immersion in accordance with Test Method E77.Thermocouples shall be calibrated in accordance with Test Method E220.Resistance thermometers shall comply with the requirements of Test Methods E644and Speciﬁcation E1137/E1137M.6.1.7Needle—Aﬂat-tipped,hardened steel needle with a cross-sectional area of1.00060.015mm2(diameter of1.120 to1.137mm)shall be used.The tip shall be free of burrs and be perpendicular to the axis of the rod.The needle shall protrude at least2mm from the end of the rod.7.Sampling7.1Unless otherwise agreed upon between the seller and the purchaser,sample in accordance with the sections on General Sampling Procedures and Speciﬁc Sampling Procedures of Practice D1898.Sampling based on engineering principles, prior to packaging,shall be considered an acceptable alterna-tive.8.Test Specimen8.1Use at least two specimens to test each sample.The specimen shall beﬂat,between3and6.5mm thick,and at least 10by10mm in area or10mm in diameter.When necessary to use multiple layers,no more than three layers of material may be stacked in order to achieve the minimum thickness.The specimens may be cut from sheet or molded material.The type of mold and the molding process used to produce test speci-mens will affect the results obtained in the test.Molding conditions shall be in accordance with the standard for the material being tested or should be agreed upon between the cooperating laboratories.N OTE3—Discrepancies in test results due to variations in molding conditions may be minimized by annealing the test specimens before the test.Since different materials require different annealing conditions, annealing procedures shall be employed only if required by the material standard or if agreed upon between the cooperating laboratories.9.Conditioning9.1If conditioning of the specimens is required,the test specimens shall be conditioned at2362°C and at5065% relative humidity for not less than40h in accordance with Practice D618.N OTE4—Conditioning periods less than the40h,as speciﬁed by Practice D618,may be used when it is shown that the Vicat softening temperature is not affected by the shorter conditioning time.Longer conditioning times may be required for some materials that take longer to reach temperature and humidity equilibrium.Refer to the applicable ASTM standards for those materials.10.Procedure10.1Prepare the immersion bath so that the temperature of the heat-transfer medium is between20and23°C at the start of the test unless previous tests have shown that for a particular material under test no error is introduced by starting at a higher temperature.The bath should be well stirred.N OTE5—Under certain conditions,it may be difficult to bring the temperature of the heat-transfer medium down to20to23°C.In these cases,the test may be started with the bath temperature at30°C.The selection of the starting temperature shall be agreed upon between the cooperating laboratories.10.2Place the specimen,which is at room temperature,on the specimen support so that it is approximately centered under the needle.The needle should not be nearer than3mm to the edge of the specimen.Gently lower the needle rod,without the extra mass,so that the needle rests on the surface of the specimen and holds it in position.10.3Position the temperature measuring device so that the sensing end is located within10mm from where the load is applied to the surface of the specimen.The sensing end should not touch the specimen.10.4Lower the assembly into the bath,taking care not to jar it in any way that would damage or dislodge the specimen.10.5Apply the extra mass required to increase the load on the specimen to1060.2N(Loading1)or5061.0N (Loading2).After a5-min waiting period,set the penetration indicator to zero.10.6Start the temperature rise.The rate of temperature increase shall be either5065°C/h(Rate A)or120610°C/h (Rate B)and shall be uniform throughout the test.The Rate A heating requirement shall be considered to be met if over every 12-min interval during the test,the temperature of the bath rises1061°C at each specimen location.The Rate B heating requirement shall be considered to be met if over every6-min interval during the test,the temperature of the bath rises 1261°C at each specimen location.The selection of the rate of rise shall be agreed upon between cooperating laboratories. See Annex A1for calibration of single temperature probe units.10.7Record the temperature of the bath when the needle has penetrated160.01mm into the test specimen.Take care to ensure that an accurate reading of the temperature is made since the rate of penetration of the specimen will be increasing rapidly at this point.10.8Express the Vicat softening temperature as the arith-metic mean of the temperature of penetration of all specimens tested.If the range of penetration temperatures for the indi-vidual test specimens exceeds2°C,record the individual results and repeat the test,using at least two new specimens. N OTE6—If a permanent record is desired,either read and record the penetration for each5°C rise in temperature until the penetration reaches 0.4mm,and at2°C intervals thereafter,or attach a displacement transducer,having the same resolution as the gauge,to each rod and continuously record the rate of penetration by means of a multichannel recorder or similar data-acquisition device.N OTE7—Some commercially available instruments record the time at which the penetration reaches a set depth.If this type of instrument is used,make a time-temperature calibration before the specimens are tested. This calibration compensates for slight variations in the heating rate. (Warning—Even though the variations may be within the speciﬁcations set forth in10.6,the compounded error over the range of the test can produce a substantial error in the Vicat softening temperature.)11.Report11.1Report the following information:11.1.1Reference to this test method,11.1.2Complete identiﬁcation of the materialtested,11.1.3Method of preparing test specimens,including con-ditioning and annealing methods used,11.1.4Initial starting temperature,11.1.5Rate of temperature rise,Rate A (50°C/h)or Rate B (120°C/h),11.1.6Total load applied to the specimen,Loading 1(1060.2N)or Loading 2(5061.0N),11.1.7Thickness of the specimen and the number of layers of the material that were used,11.1.8Heat-transfer medium,11.1.9Vicat softening temperature,expressed as the arith-metic mean of the Vicat softening temperatures of the indi-vidual specimens,and11.1.10Any observations relating to the test.12.Precision and Bias 712.1Precision —Tables 1and 2have been developed in accordance with Practice E 691.Table 1,for the case using Loading 1(1060.2N)and Heating Rate B (120610°C/h)is based on round-robin tests conducted in 1982involving ﬁve materials and differing numbers of laboratories as noted in the table.Each laboratory obtained three test results for each material.Table 2,for the case using Loading 2(50.061.0N )and Heating Rate A (5065°C/h)is based on round-robin tests conducted in 1994involving 8materials and six laboratories.Each laboratory obtained two test results for each material.In both cases,for each material,all of the individual specimensfrom all material samples were prepared by one source.Each test result was the average of two individual determinations.(Warning—The following explanations of r and R (see 12.1.1-12.1.1.3)are intended only to present a meaningful way of considering the approximate precision of this test method.The data given in Tables 1and 2should not be applied rigorously to the acceptance or rejection of material,as those data are speciﬁc to the round-robin test and may not be representative of other lots,conditions,materials,or ers of this test method should apply the principles outlined in Practice E 691to generate data speciﬁc to their laboratory and materi-als,or between speciﬁc laboratories.The principles of 12.1.1-12.1.1.3would then be valid for such data.)12.1.1Concept of r and R —If S r and S R have been calcu-lated from a large enough body of data,and for test results that were averages from testing two specimens,the following applies:12.1.1.1Repeatability,r —In comparing two test results for the same material obtained by the same operator using the same equipment on the same day,the two test results obtained within one laboratory shall be judged as not equivalent if they differ by more than the “r ”value for that material.“r ”is the interval representing the critical difference between two test results for the same material,obtained by the same operator using the same equipment on the same day in the same laboratory.12.1.1.2Reproducibility,R —In comparing two test results for the same material obtained by different operators using different equipment in different laboratories on different days,the two test results obtained by different laboratories shall be7Supporting data are available from ASTM Headquarters.Request RR:D20:1194.TABLE 1Vicat Softening Temperature Using Loading 1and Rate B,Values Expressed in Units of °CMaterialAverage S r A S R B r C R DNumber of ParticipatingLaboratoriesEthylene vinyl acetate 72.4 1.44 2.29 4.03 6.4010Polystyrene 97.30.68 2.36 1.91 6.6210High-density polyethylene 127.9 1.04 2.73 2.907.6310Polypropylene 152.5 1.13 2.83 3.167.9110Nylon 66251.20.705.061.9614.167A S r =within-laboratory standard deviation of the average.BS R =between-laboratories standard deviation of the average.Cr =within-laboratory repeatability limit =2.8S r .DR =between-laboratories reproducibility limit +2.8S R .TABLE 2Vicat Softening Temperature Using Loading 2and Rate A,Values Expressed in Units of °CMaterialAverage S r A S R B r C R D Polypropylene (PP0343)56.2 1.07 1.86 2.99 5.22Polypropylene (PP0114)92.5 1.47 4.08 4.1211.44Impact Modiﬁed Acrylic (PMMA0230V1)94.10.32 1.960.91 5.48ABS94.40.62 1.61 1.74 4.52High Heat ABS (ABS0135)100.80.34 1.530.95 4.29Unmodiﬁed Acrylic (PMMA0141V3)105.10.44 1.48 1.23 4.15Polycarbonate (PC0136)143.60.19 1.240.53 3.48Polycarbonate (PC0123)143.80.381.031.052.89AS r =within-laboratory standard deviation for the indicated material.It is obtained by pooling the within-laboratory standard deviations of the test results from all of the participating laboratories:S r =[[(S 1)2...+(S n )2]/n]1/2BS R =between-laboratories reproducibility,expressed as standard deviation:S R =[S r 2+S L 2[1/2where S L =standard deviation of laboratory means.Cr =within-laboratory critical interval between two test results =2.83S r .DR =between-laboratories critical interval between two test results =2.83S R.judged not equivalent if they differ by more than the“R”value for that material.“R”is the interval representing the critical difference between two test results for the same material, obtained by different operators using different equipment in different laboratories.12.1.1.3Any judgment in accordance with12.1.1or 12.1.1.1would have an approximate95%(0.95)probability of being correct.12.2Bias—There are no recognized standards by which to estimate the bias of this test method.13.Keywords13.1plastics;thermoplastics;Vicat softening temperatureANNEXES(Mandatory Information)A1.CALIBRATION OF SINGLE-(CENTRALIZED)TEMPERATURE PROBE UNITSA1.1If the unit in operation is of the type that has only one temperature probe in the bath,and this probe is monitored to record the softening temperature of the specimen at all the stations in the unit,then the following calibration and checks must be undertaken to ensure comparable results with units that have a temperature probe at each station.A1.2This procedure must be performed annually as a minimum to ensure proper temperature distribution and accu-racy of probe and display.A1.3Calibration will require the use of temperature meter and probe traceable to NIST,with accuracy and display resolution of0.1°C or better,a stopwatch,and any tools needed to open and adjust the unit.A1.3.1Low-temperature calibration of the unit is accom-plished by placing the NIST-traceable probe within10mm of specimen height,in the bath at three different points in the bath. The three points will be at the center and left and right ends of the bath.Start with the station closest to the centralized probe, while the unit is programmed to maintain a constant tempera-ture between20and50°C,with all stirrers operating.Allow the bath to stabilize for a minimum of5min.Read and record the readout of the calibrated probe and the units internal tempera-ture display to the nearest0.1°C.Make any necessary adjust-ments to the unit’s temperature controller to bring the bath to 60.1°C of the bath set point,allowing a stabilization time of a minimum of5min between adjustment(s)and readings.Once the calibrated probe indicates the bath is at the set point,make adjustments to the centralized probe’s display as necessary. A1.3.1.1Move the NIST-traceable probe to the other two points maintaining the probe within10mm of specimen height. Read and record the temperatures at these points,after allow-ing the probe to stabilize a minimum of5min.A1.3.2High-temperature calibration will be accomplished by programming the unit to maintain an elevated temperature near,but not exceeding,the highest temperature allowed by the heat transfer media.All covers and stations must be in place and stirrer motors operating.Place the NIST probe within10 mm of specimen height at the station closest to the centralized probe,and allow the bath to stabilize for a minimum of5min. Read and record the readout of the calibrated probe and the unit internal temperature display to the nearest0.1°C.Make any necessary adjustments to the unit’s temperature controller to bring the bath to60.1°C of the bath set point,allowing a stabilization time of a minimum of5min between adjust-ment(s)and readings.Once the calibrated probe indicates the bath is at the set point make adjustments to the centralized probe’s display as necessary.A1.3.2.1Move the NIST-traceable probe to the other two points maintaining the probe within10mm of specimen height. Read and record the temperatures at these points,after allow-ing the probe to stabilize for a minimum of5min.A1.3.3Evaluate the data from each of the three points in the bath at both low and high temperature.If any point is greater than60.5°C from the set point,have the unit serviced or repaired to correct this error.If it is not possible to correct the bath uniformity to less than0.5°C,then a thermal sensing device must be placed at each station and used to record the temperature of the bath at the time of deﬂection while running tests.The unit may be electronically modiﬁed or the use of glass thermometers(as outlined in6.1.6)may be placed at each station and manually read and recorded at the moment of specimen deﬂection.A1.3.4If the steps given in A1.3.1-A1.3.2.1have been taken and successfully completed,cool the bath down to a normal start temperature and allow the bath to stabilize.Place the NIST probe at the point in the bath that the preceding gathered data shows the greatest error.Start a test at120°C/h or 50°C/h.Read and record the temperature of both the unit’s display and the readout of the NIST probe.An offset of10to 15s between the two readings is acceptable as long as this interval is maintained throughout this test.Start the stopwatch when theﬁrst temperature is recorded.Read and record the temperature of the unit’s display and the NIST probe,main-taining any delay interval,if used,every5min for1h.A1.3.5Evaluate the data acquired during the test given in A1.3.4.Ensure that the temperature of the bath is rising at the correct rate as outlined in10.6,at both the centralized probe and the other selected test point.If either is outside the limits for the rate of rise,the unit must be serviced and rechecked before further use.If a unit fails to pass this calibration test the unit must be serviced or replaced.Placing a temperature sensing device at each station will not correct theproblemobserved in A1.3.4,as the unit’s rate of rise is outside the tolerances of this test method.A2.CALIBRATION OF MULTI TEMPERATURE SENSOR INSTRUMENTSA2.1This procedure is to be used in addition to manufac-turer’s requirements and procedures to calibrate a VICAT instrument that has multiple temperature sensors in the bath to control the temperature of the bath,or record the deﬂection temperature,or both.If the unit under test has only a single temperature sensor please refer to Annex A1.A2.2This procedure shall be performed at a frequency that conforms to the end user’s quality system requirements.A2.3All test equipment,that is,temperature meters,temperature sensors,gauge blocks,stopwatches,etc.,used to perform this procedure must be calibrated and traceable to NIST or other recognized national standards.Temperature measuring equipment must have a resolution of 0.1°C or better,gauge blocks used to calibrate the deﬂection must be accurate to 0.001mm or better,stopwatches must be accurate to 0.1s or better.A2.4Temperature calibration shall be done in accordance with the manufacturer’s procedures and the following guide-lines:A2.4.1The temperature shall be calibrated at a minimum of two points.One being at or near 8the start temperature of the test and the other at or above the maximum temperature used by the end user.Care must be taken not to exceed the maximum safe temperature of the heat transfer media.A2.4.2If moving the reference temperature sensor(s)from location to location in the bath,a minimum of 5min must be allowed between moving the temperature sensor and reading the temperature values.A2.4.3Test stations and covers shall be in their normal test position when possible and all agitators operating during the calibration.A2.4.4Reference temperature sensor(s)sensitive part shall be placed as close as possible to the Unit Under Test (UUT)sensor(s),and #10mm from the specimens.A2.4.5Adjustment of the UUT shall be made so the display(s)of the UUT is 60.1°C of the values indicated by the reference temperature sensor(s).A2.5Once the static temperature calibration has been completed,cool the instrument down to a normal start tem-perature and allow the bath temperature to stabilize.Program the UUT to ramp up the bath temperature at a rate of 120°C/h or 50°C/h as dictated by the use of the UUT.If the UUT is used at both ramp rates separate tests must be conducted at each ramp rate.Read and record the temperature at each station at intervals not to exceed those stated in section 10.6of this test method,until the UUT reaches the high temperature calibrationpoint.These temperatures shall be read and recorded by software control or data acquisition from the UUT using the internal temperature sensors after they have been calibrated by the above steps or by the use of external traceable temperature measurement equipment.Perform multiple ramps if necessary to verify each station.A2.5.1Evaluate the data acquired during the proceeding test(s)to ensure that the temperature rate of rise at each station is within the tolerances outlined in Section 4of this test method.It is allowable for the ﬁrst 10min of the ramp to be outside of the prescribed tolerances as many instruments use a PID control for the heating,and it is normal for the controller to tune itself to the correct power and interval requirements to perform the required ramp rate.If any station is found to be outside the prescribed tolerances beyond the ﬁrst 10min,that station shall not be used for testing until repairs or adjustments are made to bring the station back into tolerance.A2.6A test must be made on each station using a test specimen made of a material having a low coefficient of expansion 9to determine the thermal expansion of the station,load rod and associated parts.The calibrated temperature range of the UUT shall be covered and a compensation value determined at a minimum of each 20°C rate of rise.If the UUT is used at both ramp rates of 120°C/h and 50°C/h then a compensation value must be determined independently for each ramp rate.If this compensation value is greater than 0.02mm [0.0008in.]its algebraic sign shall be noted and the compensation value shall be applied to each test by adding it algebraically to the reading of apparent deﬂection of the test specimen.It is permissible to perform this test in conjunction with the rate of rise test as outlined in A2.5.A2.7The deﬂection indicators and critical mechanical dimensions,that is,needle point(s),must also be calibrated/veriﬁed using traceable calibration tools.The manufacturer’s requirement and procedures will provide details on how to perform the actual tasks;the following are intended to provide the user with tolerances and other necessary guidelines.A2.7.1The deﬂection indicators must be calibrated to a tolerance of 60.01mm of the reference.A2.7.2The critical mechanical dimensions must meet the requirements outlined in 6.1.4and 6.1.7of this test method.A2.7.3The weights must be veriﬁed and conform to the speciﬁcation outlined in 6.1.5of this test method.A2.7.4When determining the weight of the load rod(s)and deﬂection indicator any spring force acting on the specimen must be accounted for.If the design of the apparatus uses a spring force that acts downward (as part of the load)or8Near is deﬁned in this Annex as 65°C.9Borosilicate (quartz)has been found suitable for thispurpose.。

ASTM F1173

Designation:F1173–01An American National Standard Standard Speciﬁcation forThermosetting Resin Fiberglass Pipe Systems to Be Usedfor Marine Applications1This standard is issued under theﬁxed designation F1173;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1This speciﬁcation covers reinforced thermosetting resin pipe systems with nominal pipe sizes(NPS)1through48in. (25through1200mm)which are to be used for allﬂuids approved by the authority having jurisdiction in marine piping systems.1.2Values stated in inch-pound are to be regarded as the standard.Values given in parentheses are for information only.1.3The dimensionless designator NPS has been substituted for traditional terms as“nominal diameter,”“size,”and“nomi-nal size.”1.4The following safety hazards caveat pertains to the test methods which are included in this speciﬁcation.This standard does not purport to address all of the safety concerns,if any, associated with its use.It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.2.Referenced Documents2.1ASTM Standards:D883Terminology Relating to Plastics2D1598Test Method for Time-To-Failure of Plastic Pipe Under Constant Internal Pressure3D1599Test Method for Resistance to Short-Time Hydrau-lic Failure Pressure of Plastic Pipe,Tubing,and Fittings3 D2105Test Method for Longitudinal Tensile Properties of “Fiberglass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe and Tube3D2310Classiﬁcation for Machine-Made“Fiberglass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe3D2584Test Method for Ignition Loss of Cured Reinforced Resins4D2924Test Method for External Pressure Resistance of “Fiberglass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe3D2992Practice for Obtaining Hydrostatic or Pressure De-sign Basis for“Fiberglass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe and Fittings3D3567Practice for Determining Dimensions of“Fiber-glass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe and Fittings3D5028Test Method for Curing Properties of Pultrusion Resins by Thermal Analysis5D5686Speciﬁcation for“Fiberglass”(Glass-Fiber-Reinforced Thermosetting-Resin)Pipe and Pipe Fittings, Adhesive Bonded Joint Type Epoxy Resin,for Condensate Return Lines3E1529Test Methods for Determining Effects of Large Hydrocarbon Pool Fires on Structural Members and As-semblies6F412Terminology Relating to Plastic Piping Systems3 2.2Other Documents:ANSI B16.1Cast Iron Pipe Flanges and Flanged Fittings7 ANSI B16.5Pipe Flanges and Flanged Fittings7IMO Resolution A.753(18)Guidelines for the Application of Plastic Pipes on Ships8NSF-619Code of Federal Regulations21CFR175.105, 21CFR177.2280,21CFR177.2410,and21CFR177.24208 Code of Federal Regulations Title46,Part56,for Piping Systems,and Subpart56.60-25for Nonmetallic Materials8 IMO Resolution A.653(16)Recommendation on Improved1This speciﬁcation is under the jurisdiction of ASTM Committee F25on Ships and Marine Technology and is the direct responsibility of Subcommittee F25.13on Piping Systems.Current edition approved Dec.10,2001.Published April2002.Originally published as F1173–st previous edition F1173–95.2Annual Book of ASTM Standards,V ol08.01.3Annual Book of ASTM Standards,V ol08.04.4Annual Book of ASTM Standards,V ol08.02.5Annual Book of ASTM Standards,V ol08.03.6Annual Book of ASTM Standards,V ol04.07.7Available from American National Standards Institute,25W.43rd St.,4th Floor,New York,NY10036.8Available from Standardization Documents Order Desk,Bldg.4Section D,700 Robbins Ave.,Philadelphia,PA19111-5098,Attn:NPODS.9Available from the National Sanitation Foundation,P.O.Box130140,789N.Dixboro Rd.,Ann Arbor,MI48113-0140.1Copyright©ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.Fire Test Procedures for Surface Flammability of Bulk-head,Ceiling,and Deck Finish Materials 8IMO Resolution MSC.61(67)International Code for Appli-cation of Fire Test Procedures 8OTI 95634Jet-Fire Resistance Test of Passive Fire Protec-tion Materials 102.3ISO Documents:900177573.Terminology3.1Deﬁnitions are in accordance with Terminologies D 883and F 412.3.2Deﬁnitions of Terms Speciﬁc to This Standard:3.2.1continuously electrically conductive ,adv —pipe and ﬁttings made conductive using discretely conductive materials or layers.3.2.2homogeneously electrically conductive ,adv —pipe and ﬁttings made conductive using a resin additive so that conductivity is maintained between any two points on the pipe or ﬁtting.3.2.2.1Discussion —For conveying nonconducting ﬂuids (those having conductance less than 1000pico-Siemens per metre),pipe systems which are continuously or homoge-neously conductive or have conductivity from the inside surface to the outside surface are recommended.In accordance with IMO Resolution A.753(18),all pipe located in a hazard-ous area,regardless of the ﬂuid being conveyed,must be electrically conductive.3.2.3maximum operating pressure ,n —the highest pressure that can exist in a system or subsystem under normal operating conditions.3.2.4representative piping system ,n —a system composed of a single manufacturer’s pipes,ﬁttings,joints,and adhesives that would normally be used by a customer or installer.4.Classiﬁcation4.1General —Pipe and ﬁttings are to be classiﬁed using the following system which is similar to that of Classiﬁcation D 2310for pipe.4.1.1Types :4.1.1.1Type I —Filament wound.4.1.1.2Type II —Centrifugally cast.4.1.1.3Type III —Molded (ﬁttings only).4.1.2Resin :4.1.2.1Resin 1—Epoxy resin.4.1.2.2Resin 2—Vinylester resin.4.1.2.3Resin 3—Polyester resin.4.1.2.4Resin 4—Phenolic resin.4.1.2.5Resin 5—Customer-speciﬁed resin.4.1.3Class :4.1.3.1Class A —No liner.4.1.3.2Class B —Reinforced liner.4.1.3.3Class C —Nonreinforced liner.4.2Pressure Rating —Pipe and ﬁttings shall be classiﬁed asto the method used to obtain their pressure rating (refer to Appendix X1).4.2.1Rating Method 1—Short-term test.4.2.2Rating Method 2—Medium-term (1000-h)test.4.2.3Rating Method 3—Long-term (10000-h)test.4.2.4Rating Method 4—Long-term (10000-h)regression test.4.3Fire Endurance —Piping systems are to be classiﬁed in accordance with the following cells if ﬁre performance is to be speciﬁed (refer to Appendix X2).4.3.1Fluid :4.3.1.1Fluid E —Empty.4.3.1.2Fluid EF —Initially empty for 5min,followed by ﬂowing water.Fluid velocity of 3-ft/s maximum during quali-ﬁcation test.)4.3.1.3Fluid S —Stagnant water.4.3.2Fire Type :4.3.2.1Fire Type JF —Jet ﬁre with heat ﬂux between 95100and 126800Btu/(h-ft 2)(300and 400kW/m 2).4.3.2.2Fire Type IF —Impinging ﬂame with heat ﬂux of 36011Btu/(h-ft 2)(113.6kW/m 2).4.3.2.3Fire Type HF —Hydrocarbon furnace test at 2012°F (1100°C).4.3.3Integrity/Duration :4.3.3.1Integrity A —No leakage during or after ﬁre test.4.3.3.2Integrity B —No leakage during ﬁre test,except a slight weeping is acceptable.Capable of maintaining rated pressure for a minimum of 15min with a leakage rate of 0.05gal/min (0.2L/min)after cooling.4.3.3.3Integrity C —Minimal or no leakage (0.13gal/min (0.5L/min))during ﬁre test.Capable of maintaining rated pressure with a customer-speciﬁed leakage rate after cooling.4.3.3.4Duration —The duration of the test shall be speciﬁed in minutes and shall be speciﬁed or approved by the authority having jurisdiction.5.Ordering Information5.1When ordering pipe and ﬁttings under this speciﬁcation,the following should be speciﬁed (where applicable):5.1.1Service Conditions :5.1.1.1Fluid being transported.5.1.1.2Design temperature (reference6.6).5.1.1.3Internal design pressure.5.1.1.4External design pressure.5.1.2General Information :5.1.2.1Type (reference 4.1.1).5.1.2.2Resin (reference 4.1.2).5.1.2.3Class (reference 4.1.3).5.1.3Pressure Rating Method (Internal Only)(reference 4.2).5.1.4Fire Endurance :5.1.4.1Fluid (reference 4.3.1).5.1.4.2Fire type (reference 4.3.2).5.1.4.3Integrity (reference 4.3.3).5.1.4.4Flame spread rating (reference6.4).5.1.4.5Smoke and other toxic products of combustion (reference6.5).5.1.5NPS.10Offshore Technology Information (OTI)Report is available from Health and Safety Executive,HSE Information Centre,Broad Ln.,Sheffield,S37HQ,U.K.5.1.6Manufacturer’s Identiﬁcation(part number,product name,and so forth).5.1.7Speciﬁc job requirements(that is,potable water usage, electrical conductivity).6.Performance Requirements6.1Internal Pressure—All components included in the piping system shall have pressure ratings suitable for the intended service.Pressure ratings shall be determined in accordance with Appendix X1using the method speciﬁed by the customer or a longer-term method,if available.If,for example,a Rating Method2—medium-term test is speciﬁed and data for Rating Method3—long-term test is available,then the long-term test data is acceptable.Note that for some components,particularly specialtyﬁttings,long-term testing is not practical and ratings for these items will typically be determined using Rating Test Method1.6.2External Pressure—All pipe included in the piping system shall have external pressure ratings suitable for the intended service.External pressure ratings shall be determined by dividing the results of Test Method D2924by a minimum safety factor of3.6.3Fire Endurance—The piping system shall have theﬁre endurance required by the authority having jurisdiction based on the intended location and service.Fire endurance shall be determined using the appropriate method in Appendix X2. 6.4Flame Spread—The authority having jurisdiction shall designate anyﬂame spread requirements based on the location of the piping.For ships,mobile offshore drilling units (MODU’s),andﬂoating oil production platforms subject to the requirements of SOLAS or Title46of the U.S.Code of Federal Regulations,performance shall be determined by test proce-dures given in IMO Resolution MSC.61(67),Annex1,Part 5—Test for Surface Flammability,as modiﬁed for pipes in Appendix3of IMO Resolution A.753(18).6.5Smoke and Other Toxic Products of Combustion—The authority having jurisdiction shall designate any smoke and toxicity requirements based on the location of the piping.For ships,MODUs,andﬂoating oil production platforms subject to the requirements of SOLAS or Title46of the U.S.Code of Federal Regulations,performance shall be determined by test procedures given in IMO Resolution MSC.61(67),Annex1, Part2—Smoke and Toxicity Test,as modiﬁed in B.9.0of Appendix B—Fire Performance Tests.6.6Temperature—The maximum working temperature shall be at least36°F(20°C)less than the minimum glass transition temperature(determined in accordance with Test Method D5028or equivalent)or heat distortion temperature (determined in accordance with ISO75Method A,or equiva-lent)of the resin or plastic material.The minimum glass transition temperature or heat distortion temperature,which-ever is less,shall not be less than176°F(80°C).N OTE1—Glass transition temperature shall be used for in-process quality control testing(reference9.1.4,9.2.4,and9.3.3).6.7Material Compatibility—The piping material shall be chemically compatible with theﬂuid being carried and any ﬂuid in which it will be immersed.6.8Electrical Resistance—Conductive piping systems shall have a resistance per unit length not to exceed3.053104V/ft (13105V/m)when tested in accordance with Appendix X3. Resistance to earth at any location on an installed piping system required to be conductive shall be no greater than13 106V.6.9Static Charge Shielding—Conductive piping systems shall have a maximum resulting voltage not to exceed1%of the supply voltage induced on the exterior surface of the pipe when tested in accordance with Appendix X3.6.10Potable Water Usage—The material,including pipe,ﬁttings,adhesive,and any elastomeric gaskets required shall have no adverse effect on the health of personnel when used for potable water service.Material shall conform to National Sanitation Standard61or meet the requirements of FDA Regulations21CFR175.105and21CFR177.2280,21CFR 177.2410,or21CFR177.2420.7.Other Requirements7.1Flanges—Standardﬂanges shall have bolt patterns in accordance with ANSI B16.5Class150for nominal pipe sizes 24-in.and smaller and in accordance with ANSI B16.1Class 125for largerﬂanges.Consult the manufacturer’s literature for bolt length,torque speciﬁcations,and tightening sequence. 7.2Military Usage—Piping andﬁttings used in military applications shall comply with the provisions of Appendix D, Supplementary Requirements to Speciﬁcation F1173for U.S. Navy use.8.Workmanship and Appearance8.1All pipe,ﬁttings,and spools shall be visually inspected for compliance with the requirements stated in Table1,and,if appropriate,either repaired or rejected.After all minor repairs, a pressure test in accordance with9.1.1,9.2.1,or9.3.1shall be performed on the component.9.Inspection and Sampling9.1Pipe:9.1.1Pressure Tests—A minimum of5%of pipe joints shall be tested at a pressure of not less than1.5times the pipe system pressure rating.9.1.2Lot Size—A lot of pipe shall consist of150joints,or fractions thereof,of one size,wall thickness,and grade in continuous production.9.1.3Short-Term Burst Tests—Short-term hydrostatic burst tests shall be conducted in accordance with Test Method D1599at a minimum frequency of one test per lot.If the measured value is less than85%of the published value,the lot is rejected or subject to retest.9.1.4Degree of Cure—The glass transition temperature (Tg)shall be determined at a minimum frequency of one test per production lot.If the measured value is more than10°F less than the value in the manufacturer’s speciﬁcation,the lot is rejected or subject to retest.9.1.5Glass Content—The glass content(mass fraction ex-pressed as percentage)of at least one sample per production lot shall be determined in accordance with Test Method D2584.If the measured glass content is not within5%of the value in the manufacturer’s speciﬁcation,the lot is rejected or subject toretest.9.1.6Wall Thickness —Total wall thickness and reinforced wall thickness shall be determined in accordance with Practice D 3567once per every production lot.Total and reinforced wall thickness shall be as speciﬁed in Table 2.Any out of tolerance components shall be rejected and the remainder of the lot be subject to retest.9.2Fittings :9.2.1Pressure Tests —A minimum of 5%of each ﬁtting lot shall be tested at a pressure of not less than 1.5times the pipe system pressure rating.All samples shall hold the test pressure for a minimum of 2min.9.2.2Lot Size —A lot shall consist of 50ﬁttings or one day’s production of a speciﬁc ﬁtting,whichever is greater.By agreement between the manufacturer,the purchaser,and the authority having jurisdiction,the lot size shall be permitted to be altered.9.2.3Short-Term Burst Tests —Short-term hydrostatic burst tests shall be conducted in accordance with Test Method D 1599at a minimum frequency of one test per lot.If themeasured value is less than 85%of the published value,the lot is rejected or subject to retest.9.2.4Degree of Cure —The Tg shall be determined at a minimum frequency of one test per production lot.If the measured value is more than 10°F less than the value in the manufacturer’s speciﬁcation,the lot is rejected or subject to retest.9.2.5Glass Content —The glass content (mass fraction ex-pressed as percentage)of at least one sample per production lot shall be determined in accordance with Test Method D 2584.If the measured glass content is not within 5%of the value in the manufacturer’s speciﬁcation,the lot is rejected or subject to retest.9.2.6Wall Thickness —Total wall thickness and reinforced wall thickness shall be determined in accordance with Practice D 3567once per every production lot.Total and reinforced wall thickness shall be as speciﬁed in Table 2.Any out of tolerance components shall be rejected.9.3Flanges and Mitered Fittings :9.3.1Pressure Tests —One mitered ﬁtting from each lot shall be tested to a pressure equal to or greater than 1.5times the pipe system rating.All samples shall hold the pressure for a minimum of 2min.9.3.2Lot Size —A lot shall consist of 20ﬂanges or 10mitered ﬁttings of any given conﬁguration.9.3.3Degree of Cure —The Tg shall be determined at a minimum frequency of one test per production lot.If the measured value is more than 10°F less than the value in the manufacturer’s speciﬁcation,the lot is rejected or subject to retest.TABLE 1Visual Acceptance CriteriaDefect Type DescriptionAcceptance CriteriaCorrective Action Burnthermal decomposition indicated by distortion or discoloration of the laminate surfacenone permitted reject Chip small piece broken from edge or surface—if reinforcement ﬁbers are broken,the damage is considered a crack if there are undamaged ﬁbers exposed over any area;or noﬁbers are exposed but an area greater than 0.4by 0.4in.(10by 10mm)lacks resinminor repairif no ﬁbers are exposed,and the area lacking resin is less than 0.4by 0.4in.(10by 10mm)accept Crack actual separation of the laminate which is visible on opposite surfaces and often extends through the wall;reinforcement ﬁbers are often visible/brokennone permittedrejectCrazing ﬁne hairline cracks at or under the surface of the laminate;white areas are not visiblecrack lengths greater than 1.0in (25.4mm)minor repair crack lengths less than 1.0in (25.4mm)accept Dry spot area of incomplete surface ﬁlm where the reinforcement has not been wetted by resinnone permittedreject Fracture rupture of the laminate with complete penetration;majority of ﬁbers broken;visible as lighter colored area of interlaminar separationnone permittedrejectInclusion foreign matter wound into the laminate none permitted in structural wall (treat same as pit if located atthe surface)reject Pit (pinhole)small crater in the surface of the laminate;width is on the same order of magnitude as the depth diameter greater than 0.032in.(0.8mm)or depth greater than10%of wall thickness,or bothminor repair diameter less than 0.032in.(0.8mm)and depth less than 10%of wall thicknessacceptRestriction excessive resin,adhesive,or foreign matter on the internal wall of pipe/ﬁttingsnone permittedremove by careful grinding Wear scratch shallow mark caused by improper handling,storage,or transportation,or combination thereof—if reinforcement ﬁbers are broken,the damage is considered to be a crackundamaged ﬁbers exposed over any area or no ﬁbers are exposed but an area greater than 0.4by 0.4in (10by 10mm)lacks resinminor repairno ﬁbers exposed and the area lacking resin is less than 0.4by 0.4in.(10by 10mm)acceptTABLE 2Wall Thickness TolerancesN OTE —Where measurement of the reinforced wall thickness would cause destruction or damage to the part,only the total wall thickness measurement need be taken.DimensionTolerance,%Total wall thickness +22.5A −0Reinforced wall thickness+22.5A −0AThe tolerance on total and reinforced wall thickness for ﬁttings shall refer to the manufacturer’s designated location on the body of theﬁtting.9.3.4Glass Content—The glass content(mass fraction ex-pressed as percentage)of at least one sample per production lot shall be determined in accordance with Test Method D2584.If the measured glass content is not within5%of the value in the manufacturer’s speciﬁcation,the lot is rejected or subject to retest.9.3.5Wall Thickness—Total wall thickness and reinforced wall thickness shall be determined in accordance with Practice D3567once per every production lot.Total and reinforced wall thickness shall be as speciﬁed in Table2.Any out-of-tolerance components shall be rejected and the remainder of the lot be subject to retest.9.4Retest—If any test result in9.1,9.2,or9.3,or combi-nation thereof,fails to conform to the speciﬁed requirements, the manufacturer shall be permitted to elect to reject the entire lot,or retest two additional samples from the same lot.If both of the retest specimens conform to the requirements,all items in the lot shall be accepted except the sample which initially failed.If one or both of the retest samples fail to conform to the speciﬁed requirements,the manufacturer shall reject the entire lot or test individually the remaining samples in the lot in accordance with9.1.1,9.2.1,or9.3.1,as applicable.Note that in theﬁnal case,all samples need only be subjected to the tests that the original samples failed.9.5Production Quality Documentation—The manufacturer shall have manufacturing procedures for each component to be supplied,raw material test certiﬁcates for each component to be used in manufacturing,and production quality control reports available for the procurement officer.10.Certiﬁcation10.1The pipe manufacturer shall be registered by an ac-credited agency to meet the requirements of ISO9001.For purposes of this speciﬁcation,the manufacture shall be con-sidered a“special process”as deﬁned in ISO9001,Section4.9.11.Product Marking11.1Pipe andﬁttings shall be marked with the name,brand, or trademark of the manufacturer;NPS;manufacture date; pressure rating;pressure rating method;and other information upon agreement between the manufacturer and the purchaser.12.Keywords12.1epoxy resinﬁttings;epoxy resin pipe;marine piping; nominal pipe size;thermoset epoxy resin pipeAPPENDIXES(Nonmandatory Information)X1.DETERMINATION OF INTERNAL PRESSURE RATING FOR PIPE,FITTINGS,AND JOINTSX1.1Internal pressure rating for a piping system shall be determined using one of four methods.The method used to determine this rating shall be clearly identiﬁed by the manu-facturer in published literature.X1.1.1Rating Method1—Short-Term Test Method—Two samples of each pipe,joint,ﬁtting,or other component shall be tested in accordance with Test Method D1599at ambient temperature.The maximum rating for mitered(hand lay-up)ﬁttings shall be determined by dividing the lesser result by a safety factor of5.0.The maximum rating for all other compo-nents shall be determined by dividing the lesser result by a safety factor of4.0.X1.1.2Rating Method2—Medium-Term(1000-h)Test—Two samples of each pipe,joint,ﬁtting,or other component are to be tested in accordance with Test Method D1598for a period of1000h at the rated temperature.Both specimens must survive the exposure period without leakage.The maximum rating for mitered(hand lay-up)ﬁttings shall be determined by dividing the test pressure by a safety factor of 2.5.The maximum rating for all other components shall be determined by dividing the test pressure by a safety factor of2.2.X1.1.3Rating Method3—Long-Term(10000-h)Test—Two samples of each pipe,joint,ﬁtting or other component are to be tested in accordance with Test Method D1598for a period of 10000h at the rated temperature.Both specimens must survive the exposure period without leakage.The maximum rating for mitered(hand lay-up)ﬁttings shall be determined by dividing the test pressure by a safety factor of2.0.The maximum rating for all other components shall be determined by dividing the test pressure by a safety factor of1.87.X1.1.4Rating Method4—Long-Term(10000-h)Regres-sion Test—Pipe,ﬁttings,and joints shall be tested in accor-dance with Practice D2992Procedure B at the rated tempera-ture.The pressure rating for all components shall be determined in accordance with the hydrostatic design basis (HDB)and lower conﬁdence limit(LCL)as calculated in the test method.Ratings shall be determined by dividing the LCL at20years by a factor of1.5.Scaling of the results is allowed for pipe bodies only in accordance with the ISO equation:S3SF5P~D2t r!/2t r(X1.1) where:S=hoop stress,psi(kPa),SF=service factor,D=mean reinforced diameter(OD−t)or(ID+t),in.(mm),P=internal pressure psig(kPa),andt r=minimum reinforced wall thickness,in.(mm).N OTE X1.1—Liner thickness is not to be used in determining inside diameter.N OTE X1.2—Coating thickness is not to be used in determining outsidediameter.X2.FIRE PERFORMANCE TESTSX2.1Fire performance tests shall be performed at an independent third-party laboratory to the satisfaction of the authority having jurisdiction.X2.2Piping Material Systems:X2.2.1Allﬁre endurance,ﬂame spread,and smoke and toxicity testing,where required,shall be conducted on each piping material system.X2.2.2Changes in either the type,amount,or architecture, or combination thereof,of either the reinforcement materials, resin matrix,liners,coatings,or manufacturing processes shall require separate testing in accordance with the requirements of this speciﬁcation.X2.3Fire-Protective Coatings:X2.3.1Where aﬁre-protective coating is necessary for achieving theﬁre endurance,ﬂame spread,or smoke and toxicity criteria,the following requirements apply:X2.3.1.1Pipes shall be delivered from the manufacturer with the protective coating on.On site application will be limited to what is physically necessary for installation(that is, joints).X2.3.1.2Theﬁre-protection properties(that is,ﬁre endur-ance,ﬂame spread,smoke production,and so forth)of the coating shall not be diminished when exposed to(1)salt water, oil,or bilge slops,(2)other environmental conditions such as high and low temperatures,high and low humidity,and ultraviolet rays,or(3)vibration.X2.3.1.3The adhesion qualities of the coating shall be such that the coating does notﬂake,chip,or powder,when subject to an adhesion test.X2.3.1.4Theﬁre-protective coating shall be resistant to impact and abrasion.It shall not be separated from the piping during normal handling.X2.4General Fire Endurance Test Requirements:X2.4.1All typical joints,including but not limited to pipe to pipe,ﬁberglassﬂange toﬁberglassﬂange,andﬁberglassﬂange to metallicﬂange intended to be used shall be tested.Elbows and tees need not be tested provided the same adhesive or method of joining utilized in straight piping tests will be used in the actual application.X2.4.2Qualiﬁcation of piping systems of sizes different than those tested shall be allowed as provided for in Table X2.1.This applies to all pipe,ﬁttings,system joints(including joints between metal andﬁberglass pipes andﬁttings),methods of joining,and any internal or external liners,coverings,and coatings required to comply with the performance criteria.X2.4.3No alterations to couplings,ﬁttings,joints,fasteners, insulation,or other components shall be made after the commencement of theﬁre endurance testing.Flange bolts shall not be retorqued after completion of theﬁre exposure testing, before hydrostatic testing.Postﬁre hydrostatic testing shall be conducted without altering the component in any way.X2.5Fire Type JF–Jet Fire—This test is based upon Health &Safety Executive document OTI95634,except that is modiﬁed so that actual pipe,joints,andﬁttings are exposed to theﬂame.X2.5.1Equipment:X2.5.1.1A propane vaporization and propulsion system capable of delivering0.6660.11lb/s(0.360.05kg/s)ﬂow under controlled conditions into a backing“box”which has the test specimen mounted at the box’s front opening.The nozzle shall be a tapered,converging type,7.875in.(200mm)in length with an inlet diameter of2.0in.(52mm)and an outlet diameter of0.70in.(17.8mm).The nozzle is to be located 3.281ft(1.0m)from the front of the box,centered across the box,and mounted horizontally between15in.(375mm)and 30in.(750mm)from the bottom of the box.Theﬂow shall directly impinge on the test specimen.X2.5.1.2Water-handling and timing equipment suitable for delivering sufficient quantities of water to produce aﬂuid velocity of3ft/s(0.91m/s)at the rated pressure of the piping system being tested.X2.5.1.3Instrumentation to record fuelﬂow rate,water ﬂow rate,temperatures in the specimen and in various loca-tions in the backing panel,and water leakage rate from the pipe assembly or individual components.X2.5.2Test Specimen—The test specimen shall be prepared with the joints,ﬁttings,andﬁre-protection coverings,if any, intended for use in the proposed application.It is up to the authority having jurisdiction to determine the number and size of test specimens,as well as requirements for the qualiﬁcation of a range of pipe diameters.X2.5.3Test Conditions:X2.5.3.1Ifﬁre-protective coatings or coverings contain or are liable to absorb moisture,the test specimen shall not be tested until the insulation has reached an air-dry condition.This condition is deﬁned as equilibrium with an ambient tempera-ture at50%relative humidity of70610°F(2065°C).Where ﬁre-protective coatings or coverings are required to enable a pipe system to pass aﬁre endurance test,the coatings’or coverings’properties should not degrade over time or due to exposure to the environment as discussed in IMO FTP Code Res A.753(18)Paragraph2.2.6,or both.X2.5.3.2The test specimen shall be planar and shall be mountedﬂush to the opening of a5by5-ft(1.5by1.5-m) open-ended,steel box(closed back panel with a depth of1.64 ft(0.5m).Suitable auxiliary equipment shall be attached to the box to ensure the box’s structural stability and to prevent any transient ambient conditions from signiﬁcantly affecting theTABLE X2.1Qualiﬁcation of Piping Systems of Different SizesSize Tested[NPS],in.(mm)Minimum Size Approved,in.(mm)Maximum Size Approved,in.(mm)0to1.5(0to40)size tested size tested 2to4(50to100)size tested4(100)5to10(125to250)size tested10(250) 12to22(300to550)size tested22(550) 24to34(600to850)size tested34(850) 36to48(900to1200)size tested48(1200)。

塑料标准样条四个标准

维卡样条
面积不小于10*10，厚度3-6.4
UL-94
阻燃样条
长：125±5宽：13.0±0.5厚：最大不超过13mm，0.75+0.05，1.5+0.1，3.0+0.2，
ISO
拉伸样条
长：大于150 宽：10.0±0.2厚：4.0±0.2
弯曲样条
简支梁：长：80±2 宽：10.0±0.2 厚：4.0±0.2跨距：16±1厚度
热变形样条
长：120.0±10.0 厚：3.0-4.2 宽：9.8-15
长：80±2.0 厚：4±0.2 宽：10±0.2
洛氏硬度
厚度：至少6mm面积：至少可以测试五个点，点与点之间距离不少于10mm，点离样片边缘不少于10mm
测试标准号对照
项目
ASTM标准
项目
ISO标准
项目
DIN标准
项目
GB标准
TS：
冲击样条
长：64±2.0 厚：12.70±0.20 宽：3.0-12.7
缺口剩余厚度：10.2±0.05 缺口底角半径：0.25R±0.05 缺口弧度：45。±1.
洛氏硬度样块
面积不小于50*50，厚度不小于六毫米
维卡样条
面积不小于10*10，厚度：3-6.5
热变形样条
长：127±2 宽： 13±0.2 厚3-13
MI
DIN EN ISO1133
MI
GB3682
HDT
D648
HDT
ISO75
HDT
DIN EN ISO75
HDT
GB1643
维卡
D1525
维卡
ISO306
维卡
DIN ENISO306

通过分子力学模型对单壁碳纳米管尺寸效应的弹性性能的研究(译文)

通过分子力学模型对单壁碳纳米管尺寸效应的弹性性能的研究Size-dependent elastic propertiesof a single-walled carbon nanotube viaa molecular mechanics modelTienchong Changa, Huajian Gaob，∗aDepartment of Civil Engineering, Tongji University, Shanghai 200092, People’s Republic of ChinabMax Planck Institute for Metals Research, Heisenbergstrasse 3, D-70569 Stuttgart, GermanyReceived 2 September 2002; received in revised form 3 January 2003; accepted 6 January 2003 摘要现在，一种基于分子力学方法的分析模型应用于研究单壁碳纳米管原子结构的弹性性质。

我们得到弹性模量和泊松比封闭形式表达式，该表达式是碳纳米管直径的函数，通过这些表达式直接将不同尺度的材料性质联系到一起。

利用实验得到的石墨的力常数解析得到的非手性的碳纳米管弹性性质与紧束缚数值计算的结果进行比较。

这项研究是一个发展纳米模型应用程序的分子力学分析方法的初步努力。

关键词：碳纳米管，弹性性能，分子力学，连续介质力学1．简介自从在1991年的发现后(Iijima，1991年），由于其特殊的机械性能和电子性能，碳纳米管被广泛认为是在纳米工程学中非常有应用前途的材料（Dresselhaus等，1996;Yakobson和Smalley，1997;Fischer，1998年; Thostensona等，2001。

Cohen，2001年，钱等，2002等），例如，实验研究和数值模拟表明，碳纳米管因有TPa数量级的杨氏模量，(Treacy等，1996;Yakobson等，1996;Falvo等，1997;Wong等，1997;Bernholc 等，1998;克里希南等，1998;姚和Lordi，1998年; Lourie和Wagner,1998年; Salvetat等，1999;Hernandez等，1999年;Sanchez-Portal 等，1999；等等），在超强复合材料和纳米机械装置有广泛应用前景。

MESSKO产品_说明书_指针式温度计_Trasy2

CAUTION
Measuring instruments are sensitive. All parts should therefore be protected against falling and against knocks and vibrations.
The capillary tube may not be shortened otherwise the pressurized measuring system will be destroyed.
4
4
4.1
Connecting the microswitches
4
5
4.2
Checking and adjusting the microswitches 5
5
5
Indication control and readjustment
5
6
6
Maintenance
6
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7
Technical data
6
7
NOTE
These notes give important information on a certain issue.
1.2 Speciﬁed application Pointer thermometers are used to measure temperatures on power transformers, reactors or similar equipment. It is important to read and observe the limit values for operation indicated on the nameplate and in the operating instructions prior to commissioning the device.

ASTM D792_2000

ASTM-D792ADOPTION NOTICEASTM-D792, "DENSITY AND SPECIFIC GRAVITY (RELATIVE DENSITY) OFPLASTICS BY DISPLACEMENT", was adopted on 15-JUL-91 for use bythe Department of Defense (DoD). Proposed changes by DoDactivities must be submitted to the DoD Adopting Activity:Commander, Defense Supply Center Philadelphia, ATTN: DSCP-ILEA,700 Robbins Avenue, Philadelphia, PA 19111-5096. Copies of thisdocument may be purchased from the American Society for Testingand Materials 100 Barr Harbor Drive West Conshohocken,____________________ Pennsylvania, United States, 19428-2959. /--`-`-`,,`,,`,`,,`---Custodians:Adopting Activity:DLA - ISArmy - MRNavy - SHAir Force - 11DLA - GSReviewer Activities:Navy - YDFSC 9330DISTRIBUTION STATEMENT A:Approved for public release; distributionis unlimited.Copyright ASTM InternationalProvided by IHS under license with ASTMNot for ResaleNo reproduction or networking permitted without license from IHSimmersion is determined,and its speciﬁc gravity(relative density)calculated.5.Signiﬁcance and Use5.1The speciﬁc gravity or density of a solid is a property that can be measured conveniently to identify a material,to follow physical changes in a sample,to indicate degree of uniformity among different sampling units or specimens,or to indicate the average density of a large item.5.2Changes in density of a single specimen may be due to changes in crystallinity,loss of plasticizer,absorption of solvent,or to other causes.Portions of a sample may differ in density because of difference in crystallinity,thermal history, porosity,and composition(types or proportions of resin, plasticizer,pigment,orﬁller).N OTE6—Reference is made to Test Method D1622.5.3Density is useful for calculating strength-weight and cost-weight ratios.6.Sampling6.1The sampling units used for the determination of spe-ciﬁc gravity(relative density)shall be representative of the quantity of product for which the data are required,in accordance with Practice D1898.6.1.1If it is known or suspected that the sample consists of two or more layers or sections having different speciﬁc gravities,either completeﬁnished parts or complete cross sections of the parts or shapes shall be used as the specimens, or separate specimens shall be taken and tested from each layer.The speciﬁc gravity(relative density)of the total part cannot be obtained by adding the speciﬁc gravity of the layers, unless relative percentages of the layers are taken into account.7.Conditioning7.1Conditioning—Condition the test specimens at 2362°C and5065%relative humidity for not less than40 h prior to test in accordance with Procedure A of Practice D618,unless otherwise speciﬁed by the contract or relevant material speciﬁcations.In cases of disagreement,the tolerances shall be61°C and62%relative humidity.7.2Test Conditions—Conduct tests in the standard labora-tory atmosphere of2362°C and5065%relative humidity, unless otherwise speciﬁed in this speciﬁcation or by the contract or relevant material speciﬁcation.In cases of disagree-ment,the tolerances shall be61°C and62%relative humid-ity.TEST METHOD A FOR TESTING SOLID PLASTICS IN WATER(SPECIMENS1TO50g)8.Scope8.1This test method involves weighing a one-piece speci-men of1to50g in water,using a sinker with plastics that are lighter than water.This test method is suitable for plastics that are wet by,but otherwise not affected by water.9.Apparatus9.1Analytical Balance—A balance with a precision within 0.1mg,accuracy within0.05%relative(that is,0.05%of the mass of the specimen in air),and equipped with a stationary support for the immersion vessel above the balance pan(“pan straddle”).N OTE7—Assurance that the balance meets the performance require-ments should be provided by frequent checks on adjustments of zero point and sensitivity and by periodic calibration for absolute accuracy,using standard masses.9.2Sample Holder,corrosion-resistant(for example,wire, gemholder,etc.).9.3Sinker—A sinker for use with specimens of plastics that have speciﬁc gravities less than1.000.The sinker shall:(1)be corrosion-resistant;(2)have a speciﬁc gravity of not less than 7.0;(3)have smooth surfaces and a regular shape;and(4)be slightly heavier than necessary to sink the specimen.The sinker should have an opening to facilitate attachment to the specimen and sample holder.9.4Immersion Vessel—A beaker or other wide-mouthed vessel for holding the water and immersed specimen.9.5Thermometer—A thermometer with an accuracy of 60.1°C is required.10.Materials10.1Water—The water shall be substantially air-free and distilled or demineralized water.N OTE8—Water may be rendered substantially air-free by boiling and cooling or by shaking under vacuum in a heavy-walled vacuumﬂask. (Precaution:Use gloves and shielding.)If the water does not wet the specimen,a few drops of a wettingagent shall be added.If this solution does not wet the specimen,Method B shall be used.11.Test Specimen11.1The test specimen shall be a single piece of the material under test of any size and shape that can conveniently be prepared and tested,provided that its volume shall be not less than1cm3and its surface and edges shall be made smooth.The thickness of the specimen should be at least1mm for each1 g of weight.A specimen weighing1to5g usually will be found convenient,but specimens up to approximately50g may be used(Note9).Care should be taken in cutting specimens to avoid changes in density resulting from compressive stresses or frictional heating.N OTE9—Speciﬁcations for certain plastics require a particular method of specimen preparation and should be consulted if applicable.11.2The specimen shall be free from oil,grease,and other foreign matter.12.Procedure12.1Measure and record the water temperature.12.2Weigh the specimen in air to the nearest0.1mg for specimens of mass1to10g or to the nearest mg for specimens of mass more than10to50g.12.3If necessary,attach to the balance a piece ofﬁne wire sufficiently long to reach from the hook above the pan to the support for the immersion vessel.In this case attach the specimen to the wire such that it is suspended about25mm above the vessel support.N OTE10—If a wire is used the specimen may be weighed in air after hanging from the wire.In this case,record the mass of the specimen,a =(mass of specimen +wire,in air)−(mass of wire in air).12.4Mount the immersion vessel on the support,andcompletely immerse the suspended specimen (and sinkers,ifused)in water (10.1)at a temperature of 2362°C.The vesselmust not touch sample holder or specimen.Remove anybubbles adhering to the specimen,sample holder,or sinker,paying particular attention to holes in the specimen and sinker.Usually these bubbles can be removed by rubbing them with awire.If the bubbles cannot be removed by this method or ifbubbles are continuously formed (as from dissolved gases),theuse of vacuum is recommended (Note 12).Determine the massof the suspended specimen to the required precision (12.2)(Note 11).Record this apparent mass as b (the mass of thespecimen,sinker,if used,and the partially immersed wire inliquid).Unless otherwise speciﬁed,weigh rapidly in order tominimize absorption of water by the specimen.N OTE 11—It may be necessary to change the sensitivity adjustment ofthe balance to overcome the damping effect of the immersed specimen.N OTE 12—Some specimens may contain absorbed or dissolved gases,or irregularities which tend to trap air bubbles;any of these may affect thedensity values obtained.In such cases,the immersed specimen may besubjected to vacuum in a separate vessel until evolution of bubbles hassubstantially ceased before weighing (see Test Method B).It must also bedemonstrated that the use of this technique leads to results of the requireddegree of precision.12.5Weigh the sample holder (and sinker,if used)in waterwith immersion to the same depth as used in the previous step13.Calculation 13.1Calculate the speciﬁc gravity of the plastic as follows:sp gr 23/23°C 5a /~a 1w 2b !where:a =apparent mass of specimen,without wire or sinker,in air,b =apparent mass of specimen (and of sinker,if used)completely immersed and of the wire partially im-mersed in liquid,and w =apparent mass of totally immersed sinker (if used)and of partially immersed wire.13.2Calculate the density of the plastic as follows:D 23C ,kg/m 35sp gr 23/23°C 3997.513.3If the temperature of the water is different than 23°C,the following equations will be used:M 5D D /D t (1)D –~conversion to 23°C !,kg/m 35sp gr t a /t w 3@997.51~t w –23!3M #(2)sp gr 23/235D ~conversion to 23°C !/997.5(3)where:M =slope,D D =difference between the lowest and highest tempera-ture tolerance for the standard density of water (D @A S r =within laboratory standard deviation for the individual material.It is obtained by pooling the within-laboratory standard deviations of the test results from all of the participating laboratories:S r =[[(s 1)2+(s 2)2...+(s n )2]/n]1/2B S R =between-laboratories reproducibility,expressed as standard deviation:S R =[S r 2+S L 2]1/2where S L is the standard deviation of laboratory means.C r =within-laboratory critical interval between two test results =2.83S r .D R =between-laboratories critical interval between two test results =2.83S R .different layers or areas of a nonhomogeneous product,14.1.4Report the temperature of the water.14.1.5Report the density and speciﬁc gravity with foursigniﬁcant ﬁgures.14.1.6Any evidence of porosity of the material or speci-men,14.1.7The method of test (Method A of Methods D 792),and14.1.8Date of test.15.Precision and Bias15.1See Section 23.TEST METHOD B FOR TESTING SOLID PLASTICSIN LIQUIDS OTHER THAN WATER (SPECIMENS 1TO 50g)16.Scope16.1Test Method B uses a liquid other than water for testingone-piece specimens,1to 50g,of plastics that are affected bywater or which are lighter than water.17.Apparatus17.1The apparatus shall include the balance,wire,andimmersion vessel of Section 8,and,optionally,the following:17.2Pycnometer with Thermometer —A 25-mL speciﬁcgravity bottle with thermometer,or17.3Pycnometer —A pycnometer of the Weld type,prefer-ably with a capacity of about 25mL and an external cap overthe stopper.17.4Thermometer —A thermometer having ten divisionsper degree Celsius over a temperature range of not less than5°C or 10°F above and below the standard temperature,andhaving an ice point for calibration.A thermometer shortenough to be handled inside the balance case will be foundconvenient.ASTM Thermometer 23C (see Speciﬁcation E 1)and Anschütz-type thermometers have been found satisfactoryfor this purpose.17.5Constant-Temperature Bath —An appropriate constant-temperature bath adjusted to maintain a temperature of 2360.1°C.18.Materials 18.1Immersion Liquid—The liquid used shall not dissolve,swell,or otherwise affect the specimen,but should wet it and should have a speciﬁc gravity less than that of the specimen.In addition,the immersion liquid should be nonhygroscopic,have a low vapor pressure,a low viscosity,and a high ﬂash point,and should leave little or no waxy or tarry residue on evaporation.A narrow cut distilled from kerosine meets these requirements for many plastics.The speciﬁc gravity 23/23°C of the immersion liquid shall be determined shortly before and after each use in this method to a precision of at least 0.1%relative,unless it has been established experimentally in the particular application that a lesser frequency of determination can be used to assure the desired precision.N OTE 15—For the determination of the speciﬁc gravity of the liquid,the use of a standard plummet of known volume (Note 15)or of Method A,C,or D of Test Methods D 891,using the modiﬁcations required to give speciﬁc gravity 23/23°C instead of speciﬁc gravity 60/60°F,is recom-mended.One suggested procedure is the following:If a constant-temperature water bath is not available,deter-mine the mass of the clean,dry pycnometer with thermometer to the nearest 0.1mg on an analytical balance.Fill the pycnometer with water (10.1)cooler than 23°C.Insert the thermometer-stopper,causing excess water to be expelled through the side arm.Permit the ﬁlled bottle to warm in air until the thermometer reads 23.0°C.Remove the drop of water at the tip of the side arm with a bit of ﬁlter paper,taking care not to draw any liquid from within the capillary,place the cap over the side arm,wipe the outside carefully,and determine the mass of the ﬁlled bottle again to the nearest 0.2mg.Empty the pycnometer,dry,and ﬁll and determine the mass with the other liquid in the same manner as was done with the water.TABLE 2Test Method BSpeciﬁc Gravity Tested in Liquids Other Than Water MaterialMean S r A S R B r C R D Polypropylene0.90230.001390.002390.003930.00676LDPE0.92150.001090.001950.003080.00552HDPE0.96780.001260.001890.003560.01007Thermoset1.31300.001600.002170.004530.01282A S r =within laboratory standard deviation for the individual material.It is obtained by pooling the within-laboratory standard deviations of the test results from all of the participating laboratories:S r =[[(s 1)2+(s 2)2...+(s n )2]/n]1/2B S R =between-laboratories reproducibility,expressed as standard deviation:S R =[S r 2+S L 2]1/2where S L is the standard deviation of laboratory means.C r =within-laboratory critical interval between two test results =2.83S r .D R =between-laboratories critical interval between two test results =2.83S R .TABLE 3Standard Density of Water A°Cr /kg m –30.00.10.20.30.40.50.60.70.80.921997.994897319513929490738852863084068182795722997.773075037275704568156584635161185883564823997.541251744936469744564215397337303485324024997.299427472499225020001749149712440990073525997.048002239965B 9707B 9447B 9186B 8925B 8663B 8399B 8135B AObtained from CRC Handbook of Chemistry and Physics ,78th edition,1997-1998.B The leading ﬁgure decreases by 1.Calculate the speciﬁc gravity23/23°C of the liquid,d,as follows:d5~b2e!/~w2e!where:e=apparent mass of empty pycnometer,w=apparent mass of pycnometerﬁlled with water at23.0°C,andb=apparent mass of pycnometerﬁlled with liquid at23.0°C.If a constant-temperature water bath is available,a pycnom-eter without a thermometer may be used(compare30.2).N OTE16—One standard object which has been found satisfactory for this purpose is the Reimann Thermometer Plummet.These are normally supplied calibrated for measurements at temperatures other than23/23°C, so that recalibration is necessary for the purposes of these methods. 19.Test Specimen19.1See Section11.20.Procedure20.1The procedure shall be similar to Section12,except for the choice of immersion liquid,and the temperature during the immersed weighing(12.3)shall be2360.5°C.21.Calculation21.1The calculations shall be similar to Section13,except that d,the speciﬁc gravity23/23°C of the liquid,shall be placed in the numerator:Sp gr23/23°C5~a3d/~a1w2b!22.Report22.1See Section14.23.Precision and Bias23.1Tables1and2are based on an interlaboratory study8conducted in1985in accordance with Practice E691,involv-ing5materials tested with Test Method A by6laboratories or 4materials tested with Test Method B by6laboratories.Each test result was based on two individual determinations and each laboratory obtained four test results for each material.N OTE17—Caution:The explanations of r and R are only intended to present a meaningful way of considering the approximate precision of these test methods.The data of Tables1and2should not be applied to acceptance or rejection of materials,as these data apply only to the materials tested in the round robin and are unlikely to be rigorously representative of other lots,formulations,conditions,materials,or ers of this test method should apply the principles outlined in Practice E691to generate data speciﬁc to the materials and laboratory(or between speciﬁc laboratories).The principles of23.2-23.2.3would then be valid for such data.23.2Concept of r and R in Tables1and2—If S r and S R have been calculated from a large enough body of data,and for test results that were averages from4test results for each material,then:23.2.1Repeatability—Two test results obtained within one laboratory shall be judged not equivalent if they differ by more than the r value for that material.The concept r is the interval representing the critical difference between two test results for the same material,obtained by the same operator using the same equipment on the same day in the same laboratory. 23.2.2Reproducibility—Two test results obtained by differ-ent laboratories shall be judged not equivalent if they differ by more than the R value forthat material.The concept R is theinterval representing the critical difference between two testresults for the same material,obtained by different operatorsusing different equipment in different laboratories.23.2.3Any judgment in accordance with23.2.1or23.2.2would have an approximate95%(0.95)probability of beingcorrect.23.3There are no recognized standards by which to esti-mate bias of this test method.24.Keywords24.1density;relative density;speciﬁc gravitySUMMARY OF CHANGESCommittee D20has identiﬁed the location of selected changes to these test methods since the last issue thatmay impact the use of these test methods.D792–98:(1)An ISO equivalency statement(Note2)was added and subsequent notes were renumbered.(2)Practice E380was added to the text.(3)Paragraph9.2was revised to include the identiﬁcation of a sample holder.(4)“And”was added to10.1.(5)Paragraphs12.1and14.1.4were added and subsequent paragraphs were renumbered.(6)“I r”and I R were changed to“r”and“R”in Tables1and2.(7)Section23was rewritten.D792–00:(1)Changed Note2from“There is no similar or equivalent ISO standard”to“This standard is not equivalent to ISO1183 Method A.”(2)Deleted reference to Note2in3.2.2.(3)Changed1°C to61°C in7.1.(4)Changed“if the wire is used”to“if a wire is used”in Note 13.(5)Changed the correction factor from997.6to997.5in Note 5and13.2.(6)Replaced“wire”with“sample holder”in9.3.(7)Changed accuracy from1°C to0.1°C in9.5.(8)Deleted“if the test is not performed in the standard8Supporting data are available from ASTM Headquarters.Request RR:D20-1133.laboratory atmosphere of Practice D 618”from 9.5.(9)Started ﬁrst sentence with “If necessary”in 12.3.(10)Started second sentence with “In this case”in 12.3.(11)Started ﬁrst sentence with “If a wire is used”in Note 10.(12)Replaced “wire”with “sample holder”in 12.4.(13)Replaced “wire”with “sample holder”in 12.5.(14)Added “is used and”between “wire”and “is”in Note 14.(15)Added 13.3and equations.(16)Added “Report the density and speciﬁc gravity with four signiﬁcant ﬁgures”to 14.1.5.(17)Replaced “not fewer than four”to “ten”in 17.4.The American Society for Testing and Materials takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this ers of this standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ﬁve years and if not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,at the address shown below.This standard is copyrighted by ASTM,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.Individual reprints (single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at 610-832-9585(phone),610-832-9555(fax),or service@ (e-mail);or through the ASTM website().。

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1. INTRODUCTION
The existence of a plasticity length scale has been inferred for several decades [1]. It has been an essential element in rationalizing eects of particle size on the strain hardening found in particle strengthened alloys [1±3]. It has also been invoked as an explanation for the eects of penetration depth on the nanohardness of metals [4±6], as well as the in¯uence of grain size on strain hardening [7] (the Hall±Petch eect). The phenomenon has been attributed to the geometrically-necessary dislocations introduced when the plastic deformation requires rotation and stretch gradients [1, 8]. Attempts at rationalizing measurements of crack growth at metal±oxide interfaces have also brought out the need for a length scale capable of elevating the stresses to levels required to rupture the interface [9, 10]. The most compelling experimental evidence that such a length scale exists has been provided by Fleck et al. [11], through torsional stress±strain measurements performed on Cu wires. These showed that thin (15 mm) wires required substantially higher torsions than thicker wires to cause equivalent rotations. A phenomenological theory has been developed that allows a length scale to be included in a plasticity law amenable to implementation in ®nite element programs [11±14]. From these theoretical developments, and consequent attempts at explaining experimental ®ndings of indentation [4±6],
A MICROBEND TEST METHOD FOR MEASURING THE PLASTICITY LENGTH SCALE
È LKEN1 and A. G. EVANS2{ J. S. STO
1
Materials Department, University of California, Santa Barbara, CA 93106 and 2Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, U.S.A. (Received 20 February 1998; accepted 16 April 1998)
of the foil in the loaded state is simply related to the radius of curvature by eb ha2R0 1 where h is the foil thickness. By choosing mandrils with dierent radii, R0, a range of strains may be accessed, with corresponding moments governed by the stress±strain behavior of the material (Fig. 2). 2.2. Test arrangement While the microbend test is straightforward, two aspects of the design are crucial. (i) A second mandril is needed that clamps the foil in place above that required for the bending [Fig. 1(a)]. This secures the foil, enabling symmetric loading, as well as avoiding distortion upon unloading and facilitating relocation into the confocal microscope. (ii) The loading die must be pro®led [Fig. 1(b)] and have highly polished contact surfaces to minimize friction with the foil, which otherwise causes distortion when the die is removed. The mandrils comprise W ®bers with diameters ranging from 0.125 to 2 mm. Such ®bers are commercially available. The surface strains realized with these ®bers upon using foils ranging in size from 12.5 to 50 mm are between 2 and 9% (Table 1).
5109
5110
È LKEN and EVANS: MICROBEND TEST STO
Table 1. Microbend test dimensions and bending strains Foil thickness (mm) 12.5 25 50 Fiber diameter (mm) 125 250 500 250 500 1000 500 1000 2000 Bending strain (%) 9.09 4.76 2.44 9.09 4.76 2.44 9.09 4.76 2.44
PII:
ቤተ መጻሕፍቲ ባይዱ
Acta mater. Vol. 46, No. 14, pp. 5109±5115, 1998 # 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved Printed in Great Britain S1359-6454(98)00153-0 1359-6454/98 $19.00 + 0.00
2. EXPERIMENTAL DESIGN
2.1. Microbend concept The test method is designed with the intention that it be broadly applicable to a wide range of materials in a readily available morphological form, particularly thin foils. Foils can be made by rolling, followed by annealing to produce a standard reference state. For foils, the most straightforward test approach capable of providing high ®delity measurements comprises microbending (Figs 1 and 2). In microbending, measurements of loads and bending moments are dicult because they are small. It is also dicult to control strain levels in a
AbstractÐA versatile microbend test method for determining the plasticity length scale has been developed and described. It involves the bending of a thin annealed foil around a small diameter cylindrical mandril, followed by measurement of the unloaded and loaded radii of curvature. This test fully characterizes the moment±curvature relation, subject to independent knowledge of the elastic modulus of the foil material. By using mandrils having dierent radii as well as foils with dierent thicknesses, the plasticity length scale can be established, upon comparison with tensile stress±strain measurements made on the same foils. The analysis relating the length scale to the measured moments is described and used to interpret results obtained for high purity Ni. This length scale is in the range 3±5 mm. It is dominated by rotation (rather than stretch) gradient and similar to that found previously for Cu using wire torsion tests. It is larger than the length scale determined from nanohardness tests. # 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.