dynamic simulation of soft multimaterial 3D-printed objects
ASTM+D+4065-2001
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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
Materials_Studio软件与高分子材料的结合应用
Materials_Studio 软件与高分子材料的结合应用李佳萱（南京林业大学，江苏南京210037）摘要：Materials_Studio 作为新一代的材料计算软件，帮助解决当今化学及材料工业中的许多重要问题。
文章将它和传统实验技术相比并进行了优缺点分析及举例子说明了如何利用该软件进行高分子材料的学习。
关键词：Materials_Studio ；高分子材料；传统实验机能作者简介：李佳萱（2000-），女，江苏徐州人，主要研究方向：高分子材料。
Metallurgy and materials1Materials_Studio 简介Materials_Studio 软件是由美国公司Accelrys 开发研究的一款材料计算软件。
可以帮助我们解决当今化学、材料工业中的一系列问题。
比如构型优化、性质预测以及动力学模拟和量子力学计算等。
目前它已被应用在许多行业。
一些大学甚至开设了相关的计算机材料软件研究课程。
其中主要包括的模拟方法由量子力学的密度泛函数理论、半经验的量化计算方法、分子力学、分子动力学以及介观模拟方法等。
作为一款材料计算软件它采用Client/Server 结构，Windows98、NT 或NT 系统都可以是它的客户端。
而计算服务器则可以是本机的Windows98、2000或NT ，也可以是网络上的Win 动物是2000、Windows NT 、Linux 或UNIX 系统。
它的基本环境为MS.Materials Visualizer.包括MS.Synthia.MS.Blends.MS.DPD 等模块。
其操作界面如下：2Materials_Studio 的优缺点2.1消耗少、成本低在过去材料的研究方法属于实验研究，主要研究材料的性能、结构、组成、成分、优化等问题。
是借助实验设备消耗大量的实验材料所进行的实验行为。
所使用的实验设备大多数是非常昂贵的，比如扫描透射电子显微镜、紫外吸收光谱仪、红外吸收光谱仪、投射电子显微镜等。
《CompositesPartB》：3D打印玄武岩纤维增强热塑性复合材料
《CompositesPartB》：3D打印玄武岩纤维增强热塑性复合材料3D打印是一种通过自下而上，依次添加材料，分层制造三维微观结构的过程。
在过去的十年里，3D打印技术发展迅速，特别是在汽车、航空航天、建筑和体育应用等高强度、轻量化工业复合材料领域方面。
尽管3D打印技术应用广泛，但是在打印过程中经常会遇到一个问题，那便是会形成空隙，空隙的存在会对打印出的材料的力学性能产生影响。
这些空隙通常存在于相邻的纤维之间，并且往往在打印方向上高度对齐，因此表现出了一种各向异性的模式而不是一种随机的分布。
此外，由于材料是逐层打印的，这些纤维和空隙分布在每个相应的层平面上，使得打印出材料更易受到平面各向异性效应的影响。
与此同时，这种结构的各向异性反过来又受到相关工艺参数的影响，这就导致许多研究者致力于寻找控制工艺参数的方法。
尽管如此，目前还是缺乏对3D打印造成的各向异微观结构对所得材料各向异性力学响应的影响的定性分析。
因此，仍有巨大的空间可以更深入的研究和讨论，以揭示这些材料的微观结构与其力学性能之间的关系。
近日，韩国科技先进研究院的Siwon Yu（第一作者），Soon Hyung Hong （通讯作者），韩国科技研究所的Jun Yeon Hwang （通讯作者）及其团队，在《Composites Part B》上发表了题为“Anisotropic microstructure dependent mechanical behavior of 3D-printed basalt fiber-reinforced thermoplastic composites”的文章，该文系统地研究了3D打印纤维增强复合材料的各向异性微观结构，并确定了它们对各向异性力学性能的影响。
利用高度详细的三维X射线层析成像技术，定量鉴定了由三维打印过程构建的纤维增强复合材料的各向异性组件。
此外，在实验确定的物理性能的基础上，系统地进行了X射线CT辅助模拟分析，以正确重建预测3D打印微结构的微观力学性能。
Additive manufacturing frontier
DOI: 10.29026/oea.2018.170004Additive manufacturing frontier: 3D printing electronicsBingheng Lu1, Hongbo Lan2,3* and Hongzhong Liu13D printing is disrupting the design and manufacture of electronic products. 3D printing electronics offers great potential to build complex object with multiple functionalities. Particularly, it has shown the unique ability to make embedded elec-tronics, 3D structural electronics, conformal electronics, stretchable electronics, etc. 3D printing electronics has been considered as the next frontier in additive manufacturing and printed electronics. Over the past five years, a large num-ber of studies and efforts regarding 3D printing electronics have been carried out by both academia and industries. In this paper, a comprehensive review of recent advances and significant achievements in 3D printing electronics is provided. Furthermore, the prospects, challenges and trends of 3D printing electronics are discussed. Finally, some promising so-lutions for producing electronics with 3D printing are presented.Keywords: 3D printed electronics; embedded electronics; 3D structural electronics; additive manufacturingLu B H, Lan H B, Liu H Z. Additive manufacturing frontier: 3D printing electronics. Opto-Electronic Advances1, 170004 (2018).Introduction3D printing (also known as additive manufacturing, AM) is a breakthrough technology that has been developing for more than 30 years, but has attracted more and more attentions in recent years. The American Society for Testing and Materials (ASTM) International defines AM as “A process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies”. The seven major additive manufacturing processes as classified per ISO (ASTM F42) are: material jetting, binder jetting, material extrusion, vat polymerization, powder bed fu-sion, direct energy deposition, sheet lamination. With the development of 3D printing (3DP) from rapid prototyp-ing to the end-of-use product manufacturing process, manufacturing constraints have been greatly relieved and the design freedom has been significantly expanded, in-cluding shape complexity, material complexity, hierar-chical complexity, and functional complexity1. In partic-ular, 3D printing has the unique capability to control the point-line-area in geometry and material of each layer for an object at full scale length ranging from micro to mac-ro-scale. The emerging multi-scale and multi-material 3D printing technique possesses great potential to im-plement the simultaneous and full control of fabricated object which involves the external geometry, internal architecture, functional surface, material composition and ratio as well as gradient distribution, feature size ranging from nano, micro, to macro-scale, embedded components and electro-circuit, etc. Therefore, it is able to construct the heterogeneous and hierarchical struc-tured object with tailored properties and multiple func-tionalities which cannot be achieved through the existing technologies. Such technology has been considered as a revolutionary technology and next-generation manufac-turing tool which can really fulfill the “creating material” and “creating life”, especially subvert traditional product design and manufacturing scheme. 3D printing paves the pathway and will result in great breakthrough in various applications for example functional tissue and organ, functionally graded material/structure, lattice materi-al/structure, metamaterial, smart material, functionally embedded electronic component, bio-inspired material/1State Key Laboratory for Manufacturing System Engineering, Xi’an Jiao Tong University, Xi’an 710049, China; 2Qingdao Engineering Research Center for 3D Printing, Qingdao University of Technology, Qingdao 266033, China; 3Nanomanufacturing and Nano-Optoelectronics Lab, Qingdao University of Technology, Qingdao 266033, China* Correspondence: H B Lan, E-mail: hblan99@Received 31 December 2017; accepted 21 January 2018; accepted article preview online 9 February 2018structure, multi-functionality product, soft robot, etc. Furthermore, it may promote the tremendous progress in many subjects involving material, bio-medical, elec-tronics, mechanics, bionics, aerospace, etc 2–8.In last few years, 3D printing has been utilized to fab-ricate electronics and structural electronics. More specif-ically, electronic/electrical components can be deposited and embedded in a 3D structure to form a mul-ti-functionality product by interrupting the 3D printing process. 3D printing promotes the integrated assemblage and embedded other components as results of layer-by- layer or point-by-point characteristics. Functional ele-ments such as sensors, circuits, and embedded compo-nents are now being integrated into 3D-printed products or structures, paving the way for exciting new markets, applications and opportunities. Furthermore, 3D print-ing can be harnessed to print electronics on stretchable and flexible bio-compatible “skins” with integrated cir-cuitry that can conform to irregularly-shaped mounting surfaces. Therefore, 3D printing electronics can offer great potential and unique capabilities to build complex object with multiple functionalities. Particularly, it has shown the unique ability to produce the embedded elec-tronics, 3D structural electronics, conformal electronics, stretchable electronics, OLED, etc 9–16. 3D printing appli-cations have been significantly expanded. 3D printing electronics has been considered as the next frontier in AM. Harrop J , the director of technology research firm IDTechEx, thinks the most promising use of multi mate-rial 3D printing will come in the electronics space. A large number of studies and efforts regarding 3D print-ing electronics have been carried out by both academia and industries. Great progresses in 3D printing electron-ics have been achieved in recent years. This paper mainly presents a comprehensive review of recent progresses in 3D printing electronics. Furthermore, the challenges and prospects of 3D printing electronics are discussed. This paper may provide a reference and direction for the fur-ther explorations and studies of 3D printing electronics.Recent progresses in 3D printing electronicEmbedded electronicsMany researchers have been conducted to add electronic functionality into the 3D printed structures by embed-ding electronic/electrical components and fully encapsu-lating interconnect conductive tracks. The ability of starting or stopping the build at any given layer enables the embedding of electronic components for manufac-turing conformal embedded 3D electronic systems. Tak-ing advantage of the layer-based additive manufacturing method and access to individual layers during fabrication, a single object with multiple materials and embedded components can be built now.Embedded electronics can greatly reduce the mass and assembly complexity due to the elimination of cabled interconnects and redundant electronics packaging. The ability to embed complex functioning components and electronics into 3D printed structures is very crucial for the small-satellite users who are looking to exploit 3DP in a limited space. NASA/GRC (National Aeronautics and Space Administration/Glenn Research Center) and America Makes have performed AM techniques to de-velop the embedded electronics used in the structures of spacecraft. A manufacturing platform, the multi 3D system which integrates two FDM (fused deposition modeling) systems, a CNC (computer numerical control) router for micromachining and a precision dispenser for depositing conductive inks (as shown in Fig. 1), has been developed to produce 3D, multi-material, multifunctional devices (3D-printed CubeSat module) for addressing the re-quirements of aerospace applications. The system can embed wires and components on a multi-material sub-strate to provide mechanical, electronic, thermal and electromagnetic functionality, and making conformal structures with integrated electronics. Figure 2 illustrates the process flow of the multi 3D system and fabricated parts using the platform. A CubeSat Trailblazer inte-grated a 3D-printed structure and the embeddedFig. 1 | (a ,b ) Photograph of the multi 3D system. (c ) Schematic of a fabrication example. Figure reproduced from: (a ) ref. 9, Springer International Publishing AG; (b ) ref. 14, Elsevier Ltd; (c ) ref. 9, Springer International Publishing AG.FDM1FDM2Pneumatic slideBuild platform aStrengthFlame retardancebcelectronics has been successfully launched in 20139,14,17–20. Figure 3 demonstrated the fabrication procedure of a fully encapsulated capacitive sensor. This study provides a proof of concept for advanced fully encapsulated 3D printable devices. It also verified the utility of fully em-bedded bulk conductors interconnect 21.A shoe insole with embedded pressure and tempera-ture sensing circuitry, with wireless communications chip for data transmission was fabricated by mul-ti-material 3D printing, shown in Fig. 4. Using a hybrid 3D printing process, multi-layer tactile sensors including insulating layers and sensing elements have been built. This process enables building a sensor body layer by lay-er, prints sensing elements onto the surface of the body, and builds additional layers. With the combination of ink jet, aerosol jet and extrusion print heads, the depositedmaterial can ranges from one to tens of thousands cps with a wide range of solvents. The case demonstrated the feasibility of fabricating an electronically functional ob-ject through 3D printing 22.Figure 5 shows a 3D “smart cap” with an embedded inductor–a wireless passive sensor, which has beenFig. 2 | (a ) Process flow of the multi 3D system. (b ) Fabricated parts. Figure adapted from ref. 9, Springer International Publishing AG.Build substrate with FDMabMachine channels and cavities for circuitryDispense conductive inkPlace electronic components Join traces and electronic componentsCure conductive inksabdFig. 3 | Fabrication procedure of fully encapsulated capacitive sensor with 3D printing . (a ) Polycarbonate (PC) substrate with recesses designed for all electronic components. (b ) Components arranged in in the PC substrate. (c) Electrical components with corresponding embedded wiring. (d ) Completed capacitive sensor with fully embedded wiring, diodes, LEDs, resistors, and a microcontroller. Figure reproduced from ref. 21, IEEE.cFig. 4 | (a ) Printed wireless pressure and temperature sensor within a shoe's insole. (b ) Pressure and temperature data obtained through wireless communication from the printed insole 22. Figure reproduced from ref. 22, Society for Imaging Science and Technology.Pressure 1 Pressure 2Temperature1200011000100009000T e m p e r a t u r e (d i g i t a l v a l u e )17000 16000 15000 1400013000 12000P r e s s u r e (d i g i t a l v a l u e )0 100200300400 500 600 Time (s)abdemonstrated to monitor the quality of liquid food wire-lessly. The 3D structures including both supporting and sacrificial structures are constructed with a resolution of 30 μm using the FDM technology equipped with a multi-ple-nozzle system. After removing the sacrificial materi-als, silver particles suspensions are injected subsequently and solidified as the metallic elements/interconnects. This may be the first demonstration of a comprehensive manufacture process for printing 3D additive polymer with liquid metal paste filling for the use of potential ap-plications 12.A commercial 3Dn-300 multi-material printer from nScrypt Inc. has been utilized to fabricate a fully embed-ded low-profile antenna. The 3D printer includes dual deposition heads allowing two different kinds of materi-als to be dispensed. The thermoplastic stock is dispensed from one head through a filament extrusion process to print the dielectric components. While the other head prints the ink/paste is printed from the other head with feature sizes of as small as 20 μm to build the conductive elements 23.A hybrid 3D printing process integrating stereolitho-graphy (SL) and direct print (DP) was adopted to pro-duce functional, monolithic 3D structures with embed-ded electronics. The hybrid SL/DP system (as shown in Fig. 6) consists of a 3D Systems SL 250/50 machine and an nScrypt micro-dispensing pump integrated within the SL machine through orthogonally-aligned linear transla-tion stages. The substrate/mechanical structure was fab-ricated by SL while interconnections were made by DP conductive inks. A process was developed to fabricate a 3D electronic device using the hybrid SL/DP machine with the requirement of multiple starts and stops of the SL process, removing the uncured resin from the SL sub-strate, inserting active and passive electronic components, and DP and laser curing of the conductive traces. By curing the conductive traces in situ, the construction of monolithic 3D structural electronic devices can be per-formed without removal of the device from the machine during fabrication. Functional 2D and 3D 555 timer cir-cuits have been fabricated by the hybrid 3D printing sys-tem combined with the proposed process 24. J ang et al. also presented a 3D circuit device fabrication by the hy-brid process of SL and DW technologies. A custom-made SL system was adopted instead of a commercial SL ma-chine 25.Fig. 5 | Fabrication process of 3D “smart cap” with an embedded inductor–a wireless passive sensor . (a ) 3D fabrication process with embedded and electrically conductive structures. (b ) 3D microelectronics components, including parallel-plate capacitors, solenoid-type inductors, and meandering-shape resistors. (c ) A 3D LC tank, which is formed by combining a solenoid-type inductor and a parallel-plate capacitor. (d ) A wireless passive sensor demonstration of a “smart cap”, containing the 3D-printed LC-resonant circuit. (e ) A smart cap with a half-gallon milk package, and the cross-sectional schematic diagram. (f) Sensing principle with the equivalent circuit diagram. Figure reproduced from ref. 12, Macmillan Publishers Limited.aDual 3D printing nozzlesInjection holeLiquid metalInjectionG-S-G padsCapacitorsInductorsResistorsLC tankViaSpiral inductorTop electrodeBottom electrode z yx bcd ReaderSmart capFrequency responseM a g n i t u d e o f S 11f res f res fEnergy RF coilInformationLiquid food qualityR CLfSpiral inductorSmart capViaTop electrodeBottom electrode BottleLiquid foode3D structural electronicsA hybrid technology combined with direct-write/cure (DWC) and projection microstereolithography (PμSL) has been utilized to make 3D structural electronics. A PμSL process was applied to build the 3D structures, and the conductive tracks was produced by the combination of DWC with CNT/polymer nanocomposites, which may capacitate a new generation of inexpensive 3D structural electronics in the field of consumer, defense, and medicalelectronics. The technology of hybrid manufacturing combined with AM technologies will offer capabilities of fully 3D, high-resolution, multimaterial and large-area fabrication as well as requiring only ambient processing conditions (no clean room, vacuum or high temperature environment required). Figure 7 demonstrated the hy-brid 3D printing process and the fabricated 3D structural electronics 10.Disadvantages in the manufacturing process of printedFig. 6 | (a ) Schematic of the hybrid SL/DP system. (b –d ) Fabricated 3D 555 timer circuits packaged within SL substrates. Figure reproduced from: (b –d ) ref. 24, Emerald Publishing Limited. SLA-250Z -axisnScrypt headnScrypt controller PLC controllerY -axisX -axisOptical tableDP computerScanning mirrorSL computer355 nm DPSSlaserLaser beamSL partPlatform SL resin SL vataLEDs bMicrochip Resistor Vertical interconnects Power supplyEmbedded capacitor cdThermistorFig. 7 | The hybrid 3D printing process and fabricated 3D structural electronics . (a ) Bottom insulating structure. (b ) “U” shape wire. (c ) Top insulating layer. (d ) Wires on top surface. (e ) P μSL of the bottom insulating structure. (f ) DWC of the “U” shape wire. (g ) P μSL of the topinsulating structure. (h ) DWC of wires on the top surface. (i ) Fabricated 3D structural electronics with embedded wires. Figure reproduced from ref. 10, Springer International Publishing AG.Projector lens Projected beamDispensing head Conductive material Photocurable materialPhotocurable materialConductive materialf be a cdg hicircuit board include complexity, time consuming, high-er cost, and limited product formation as the printed circuit board must be included. In order to get over these disadvantages, Jiang et al. reported a hybrid process us-ing stereolithography and direct writing (DW) to fabri-cate 3D circuit devices. The insulated structures of circuit boards having high precision were fabricated using SL. Furthermore, the circuits were made on the several layers using DW 25. Lopes et al. also presented a similar manu-facturing system using SL and DW technologies for the fabrication of 3D structural electronics 24.The integration of SL in combination with both microdispensing (nozzle deposition) and pick-and-place technology (component insertion) can produce dielectric substrates of intricately-detailed, complex shape where miniature cavities are used for the integration of press-fit electronic components. Printed conductive traces serve as electrical connections deposited by an integrated mi-cro-dispensing system within the SL system and this combination of fabrication technologies stands to revo-lutionize the integration of electronics within mechanical structures as ‘‘3D structural electronics’’. Wicker and MacDonald demonstrated the development of multiple material and multiple technology SL systems capable of manufacturing multiple material structures with me-chanical, electrical, and biochemical functionality. Some functional objects including multi-material tissue engi-neered implants, multi-material micro-scale parts, 3D structural electronics, have been successfully fabricated.Contamination issues associated with using multiple viscous materials in a single build, throughput, and lim-ited materials as well as conductive inks with low-temperature curing capabilities remain still a chal-lenging. Figure 8 shows some examples of printed 3D structural electronics 18,24.Stretchable electronicsWith the development of electronics, progresses in man-ufacturing techniques have promoted the development in the aspects of smaller, faster, more efficient. So far, the main focus has been on rigid electronics. However, re-cent interest in devices such as wearable electronics and soft robotics has led to an whole new set of electronic devices–stretchable electronics. These new devices re-quire new manufacturing solutions to integrate hetero-geneous soft functional materials. 3D printing can be harnessed to print electronics on stretchable and flexible bio-compatible “skins” with integrated circuitry that can conform to irregularly-shaped mounting surfaces.Muth et al. reported a method of embedded 3D print-ing (e-3DP) for the fabrication of strain sensors, as shown in Fig. 9. In this method, a viscoelastic ink is ex-truded into an elastomeric reservoir via a deposition nozzle. The ink is used as a resistive sensing element, while the reservoir form the matrix material. A capping (filler fluid) layer is used to fill the void space formed in the process of the nozzle translating through the reser-voir. Finally, a monolithic part was formed by theFig. 8 | Examples of printed 3D structural electronics . (a ) A gaming die which includes a microcontroller and accelerometer. (b , c ) A magnetometer system with microprocessor and orthogonal Hall Effect sensors. Figure reproduced from ref. 18, Taylor & Francis.5 mma5 mm5 mmb cFig. 9 | Schematic illustration of the embedded 3D printing (e-3DP) process and printed stretchable electronics . (a ) Schematicillustration of the e-3DP process. (b ) Photograph of a glove with embedded strain sensors produced by e-3DP. (c ) Photograph of a three-layer strain and pressure sensor in the stretched state. Figure reproduced from ref. 11, WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Printing directionabcFiller fluidco-cure of both the reservoir and filler fluid, which cov-ered and keep the embedded conductive ink fluid. The e-3DP can create soft sensors in a highly programmable and seamless manner. In order to enable e-3DP, a multi-component materials system composed of an ink, reser-voir, and filler fluid was developed. The above method that for building highly stretchable sensors by e-3DP opens new approaches for manufacturing soft functional devices for wearable electronics, human/machine inter-faces, soft robotics, and so on 11.The ability of printing integrated circuits on the flexi-ble substrate enables the electronic devices with con-formity, lightweight structure and shock-resistant con-struction, which are challenging to be achieved by using rigid substrates such as semiconductor wafers and glass plates. Bijadi et al. have successfully tested the feasibility of a syringe extrusion-based 3D printing process to print stretchable embedded electronics through the use of SS-26S conductive silicone on flexible non-conductive silicone substrates. Instead of merely using the conduc-tive silicone traces as flexible interconnects, this method used the conductive material for creating complete cir-cuitry with SMT components and embedded microcon-trollers 26. Vatani et al. presented a hybrid manufacturing process including direct print/cure (DPC) and projec-tion-based stereolithography for stretchable tactile sen-sors. The fabrication process of the tactile sensor (shown in Fig. 10) includes building the sensor body, printing sensing elements on the body surface, and building some additional layers to cover the cured sensing elements 27. The developed 3D printable stretchable sensing material is a photocurable and stretchable liquid resin filled with multi-walled carbon nanotubes (MWNTs).Other electronic/electrical products and related technologies3D printing possesses the ability of creating complex and conformal electronics integrated within a manufactured product. The Aerosol J et printing from Optomec has been demonstrated the ability of building the functional antennae on the conformal 3D printing substrates. The whole printing process accurately controls the location, geometry and thickness of the deposit and produces a smooth mirror-like surface finish to insure optimumFig. 10 | Fabricated stretchable tactile sensor using integrated PSL and DP processes . (a ) An example (partial sphere) of 3D structure built in the PSL system. (b ) Printed sensing elements using the DP process on the insulating layers built in the PSL system. (c ) Final sensor with two sensing layers. (d ) Deformed sensor. Figure reproduced from ref. 27, Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.abcdFig. 11 | 3D printed electronics using Aerosol Jet printing from Optomec . (a ) 3D MID demonstrator. (b ) 3D MID with integrated sensor. (c ) Printed conformal electronics (curve). (d ) Printed conformal electronics (dome). (e ) Printed conformal electronics (dome). (f) Sub-mm lengthscale, custom made 3D metal-dielectric. Figure reproduced from (a –c ) ref. 28, Neotech; (d –f ) ref. 29, Optomec.d e a b cfantenna performance. Some kinds of mobile device an-tennas, such as the LTE, NFC, GPS, Wifi, WLAN, and BT, have been printed through the Aerosol J et process. And the performance of such antennas tested by a cell phone component supplier is in the same level with other production methods. For now, the Aerosol Jet technolo-gy has been using for the mass production of printed 3D conformal electronics in the application of antenna and sensor. As can been seen that a hybridized DW/AM pro-cess presents great potential for creating antennas with 3-dimensional structure. Figure 11 demonstrated 3D printed electronics using Aerosol Jet printing process 28–29. Aerosol J et printing process has the ability to print conformal interconnects on 3D surfaces eliminating the need for wire bonding – for example printing electrical connections on 3D stacked die or for LED chip fabrica-tion. Runge showed Leg prosthesis part produced from PLA (Polylactic Acid) via FDM showing complexnon-planar surfaces, with surface-integrated strain gauge sensors produced by Aerosol J et TM printing and con-ductive paths deposited via micro-dispensing, both using the modular manufacturing platform. The structural elements of this leg prosthesis shaft were produced via the FDM process from PLA, a thermoplastic polymer. Its functionalization relies on a surface-integrated strain gauge realized via Aerosol J et printing. The conductive paths that lead across the part as well as the contact pads at their end were deposited through micro-dispensing. The material of the resistive sensor is a silver based ink, while interconnects and contact pads are made from sil-ver particle-filled epoxy, as shown in Fig. 12 31.The first multi-material 3D electronics printer in the world, named as Voxel8, provides an all-in-one, desktop solution for designing and prototyping next generation 3D electronic devices. Therefore, it has been regarded as a disruptive manufacture platform with the capabilities of printing embedded electronics. It enables prototyping of 3D electronic devices by the method of co-printing both thermoplastics and a highly conductive silver ink, which can be printed and cured at ambient temperature without the need for thermal annealing. Figure 13 demonstrates Voxel8 and some printed products 32.Prospect, challenges and future trends3D printing is disrupting the design and manufacture of electronic products. Functionalities of the devic-es/products fabricated by 3D printing can be significantly expanded by incorporating electronic components, such as sensors and circuits, in predetermined cavities within fabricated structures. 3D printed objects include not only traditional mechanical characteristics, but also embedded optical and electrical functions, such as sensor; all com-plex structures are difficult to produce with existingFig. 13 | Voxel8 and some printed products . (a , b ) Photograph of Voxel8 3D printer. (c ) Printed unmanned aerial vehicle. (d ) Printed antenna (dome). (e ) Printed wearable device. Figure reproduced from ref. 32, Voxel8.bac d eFig. 12 | Leg prosthesis part produced by FDM and Aerosol Jet printing . Figure reproduced from ref. 31, University of Applied Science Bremerhaven.manufacturing methods. Many emerging and innovative products, such as embedded electronics, 3D structural electronics, conformal electronics, stretchable electronics, etc., have been fabricated using the technologies. 3D printing electronics has been considered as the next fron-tier in AM. Optomec has developed a high volume printing solution for the production of 3D antenna and 3D sensors that are tightly integrated with an underlying product ranging from smartphones to industrial com-ponents. It can be utilized for high volume printing of conformal sensors and antennas directly onto preformed 3D structures. Complex electronics can be 3D printed at micron resolution which will enable cheaper smartphones and medical gadgets. Aerosol J et 3D mi-cro-structure printing is capable of ultra-high resolutions with lateral features sizes of 10 μm and aspect ratios of more than 100:1 33–37.The conductivity is still one of the major difficulties in both 3D printed electronics and general 2D printed elec-tronics because of the poor conductivity of ink caused by the low curing temperature due to the limitation of sub-strate material such as cardboard, polymers. More and more challenges in the fields of material types and pro-cessing challenges in the process of printing from 2D electronics to 3D integrated objects. Therefore, the com-patible material sets should be explored and created to provide the adequate functionality and manufacturability for the product invention by designers. Besides, the ad-hesion between the materials is also a big issue, because the conductive materials would be stripped from the substrate with a poor adhesion. This is especially im-portant case for traces that are embedded within a print and not on the surface because repair is impossible after a circuit is embedded.In order to make electronics with 3D printing, new processes should be developed to possess the ability of depositing broader types of materials. To date, there are several solutions which have the ability to fabricate mul-tifunctional 3D structures or products with embedded functional systems. Compared to other methods, the hybrid process combining FDM and direct print/writing shows higher applied potential, more flexibility. Material jetting systems seem currently to be the most successful multi-material 3D printing process among AM technol-ogies. To date, fabrication of true 3D multiple material polymeric components using material jetting processes has been demonstrated. Currently, material jetting of polymers appears to be the nearest approximation to this vision that is currently available: The combination of high resolution, controlled material deposition with the possibility of photo polymerization, which allows imme-diate solidification of the material after printing and thus facilitates deposition of materials with different func-tional or structural roles directly besides each other, pro-vides the foundation for effectively printing a structural electronics system directly. Multi-material and mul-ti-scale 3D printing will be the most promising solutions. More and more 3D printed functional electronics and products with electronics will be fabricated. 3D printing electronic technology provides a powerful tool for inno-vative product development, and extends 3D printing multiple functionalities. Significant advances in 3D printing electronics have been accomplished in the re-cent years. However, there is still a long way to go for 3D printed functional electronics and products as well as their industrial-level applications. Further potentials of 3D printing electronics need still to be explored and in-vestigated.References1. Gibson I, Rosen D W, Stucker B. Additive manufacturing tech-nologies (Springer, New York, 2010).2. Derby B. Printing and prototyping of tissues and scaffolds. Sci-ence338, 921–926 (2012).3. Lewis J A, Ahn B Y. Device fabrication: Three-dimensionalprinted electronics. Nature518, 42–43 (2015).4. Kong Y L, Tamargo I A, Kim H, Johnson B N, Gupta M K et al.3D printed quantum dot light-emitting diodes. Nano Lett14, 7017–7023 (2014).5. Lan H. Active mixing nozzle for multimaterial and multiscalethree-dimensional printing. J Micro Nano-Manuf5, 040904 (2017).6. Zheng X, Smith W, Jackson J, Moran B, Cui H et al. Multiscalemetallic metamaterials. Nature Mater15, 1100–1106 (2016).7. Vaezi M, Seitz H, Yang S. A review on 3D micro-additive manu-facturing technologies. Int J Adv Manuf Technol67, 1721–1754 (2013).8. Tian X Y, Yin L X, Li D C. Current situation and trend of fabrica-tion technologies for three-dimensional metamaterials. Opto- Electron Eng44, 69–76 (2017).9. Espalin D, Muse D W, MacDonald E, Wicker R B. 3D Printingmultifunctionality: structures with electronics. Int J Adv Manuf Technol72, 963–978 (2014).10. Lu Y, Vatani M, Choi J W. Direct-write/cure conductive polymernanocomposites for 3D structural electronics. J Mech Sci Technol27, 2929–2934 (2013).11. Muth J T, Vogt D M, Truby R L, Mengüç Y, Kolesky D B et al.Embedded 3D printing of strain sensors within highly stretcha-ble elastomers. Adv Mater26, 6307–6312 (2014).12. Wu S Y, Yang C, Hsu W, Lin L. 3D-printed microelectronics forintegrated circuitry and passive wireless sensors. Microsys Nanoeng1: 15013 (2015).13. Sun K, Wei T S, Ahn B Y, Seo J Y, Dillon S J et al. 3D Printing ofinterdigitated Li-Ion microbattery architectures. Adv Mater25, 4539–4543 (2013).14. Lehmhus D, Aumund-Kopp C, Petzoldt F, Godlinskic D,Haberkorn A et al. Customized smartness: a survey on links between additive manufacturing and sensor integration.Procedia Tech26: 284–301 (2016).15. Ladd C, So J H, Muth J, Dickey M D. 3D printing of free stand-ing liquid metal microstructures. Adv Mater25, 5081–5085。
sic模具高温模压石英玻璃物相接触角的分子动力学模拟
第３９卷第３期２０２０年３月硅㊀酸㊀盐㊀通㊀报ＢＵＬＬＥＴＩＮＯＦＴＨＥＣＨＩＮＥＳＥＣＥＲＡＭＩＣＳＯＣＩＥＴＹＶｏｌ.３９㊀Ｎｏ.３Ｍａｒｃｈꎬ２０２０ＳｉＣ模具高温模压石英玻璃物相接触角的分子动力学模拟吴㊀悠１ꎬ２ꎬ３ꎬ邹㊀斌１ꎬ２ꎬ３ꎬ王俊成１ꎬ２ꎬ３ꎬ黄传真１ꎬ２ꎬ３ꎬ朱洪涛１ꎬ２ꎬ３ꎬ姚㊀鹏１ꎬ２ꎬ３(１.山东大学机械工程学院先进射流工程技术研究中心ꎬ济南㊀２５００６１ꎻ２.山东大学高效洁净机械制造教育部重点实验室ꎬ济南㊀２５００６１ꎻ３.山东大学机械工程国家级实验教学示范中心ꎬ济南㊀２５００６１)摘要:针对高温下石英玻璃纳米液滴在ＳｉＣ模具表面接触角难以测量的问题ꎬ采用分子动力学方法ꎬ模拟研究了不同温度和粗糙表面面向模压的ＳｉＯ２/ＳｉＣ高温接触角以及ＳｉＯ２熔体的界面结构ꎮ应用压力张量法发现了ＭＳ￣Ｑ势函数模拟的ＳｉＯ２熔体表面张力较接近实际值ꎬ即ＳｉＯ２高温表面特性模拟可优先采用ＭＳ￣Ｑ势函数ꎮ针对ＳｉＣ模具纳米级表面的粗糙度ꎬ发现当粗糙度因子ｒ>１.５时润湿模式由Ｗｅｎｚｅｌ变为Ｃａｓｓｉｅ￣Ｂａｘｔｅｒꎬ此时Ｒａ的变化对接触角值无明显影响ꎬＲｍｒ值减小使得接触面积分数ｆ减小ꎬ接触角值随之增大ꎮ因此ꎬ保持ｒ大于１.５的同时适当减小Ｒｍｒ值有利于减小固液摩擦ꎬ降低石英玻璃工件和ＳｉＣ模具界面上的脱模力ꎮ随着温度升高ＳｉＯ２表面结构变得松散ꎬ导致其在ＳｉＣ表面接触角减小ꎮ在超过２３００Ｋ时接触角值的变化率增大ꎬ为减小工件￣模具界面的粘附ꎬ模压温度应选择２３００Ｋ以下ꎮ关键词:石英玻璃ꎻ碳化硅ꎻ接触角ꎻ分子动力学ꎻ模压中图分类号:Ｏ６４７.１ꎻＴＳ９４３.６５㊀㊀文献标识码:Ａ㊀㊀文章编号:１００１￣１６２５(２０２０)０３￣０９２３￣０９ＭｏｌｅｃｕｌａｒＤｙｎａｍｉｃｓＳｉｍｕｌａｔｉｏｎｏｆＨｉｇｈＴｅｍｐｅｒａｔｕｒｅＣｏｎｔａｃｔＡｎｇｌｅｆｏｒＭｏｌｄｅｄＳｉｌｉｃａＧｌａｓｓｉｎＳｉＣＤｉｅＷＵＹｏｕ１ꎬ２ꎬ３ꎬＺＯＵＢｉｎ１ꎬ２ꎬ３ꎬＷＡＮＧＪｕｎｃｈｅｎｇ１ꎬ２ꎬ３ꎬＨＵＡＮＧＣｈｕａｎｚｈｅｎ１ꎬ２ꎬ３ꎬＺＨＵＨｏｎｇｔａｏ１ꎬ２ꎬ３ꎬＹＡＯＰｅｎｇ１ꎬ２ꎬ３(１.ＣｅｎｔｅｒｆｏｒＡｄｖａｎｃｅｄＪｅｔＥｎｇｉｎｅｅｒｉｎｇＴｅｃｈｎｏｌｏｇｉｅｓꎬＳｃｈｏｏｌｏｆＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇꎬＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙꎬＪｉｎａｎ２５００６１ꎬＣｈｉｎａꎻ２.ＫｅｙＬａｂｏｒａｔｏｒｙｏｆＨｉｇｈＥｆｆｉｃｉｅｎｃｙａｎｄＣｌｅａｎＭｅｃｈａｎｉｃａｌＭａｎｕｆａｃｔｕｒｅꎬＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙꎬＭｉｎｉｓｔｒｙｏｆＥｄｕｃａｔｉｏｎꎬＪｉｎａｎ２５００６１ꎬＣｈｉｎａꎻ３.ＮａｔｉｏｎａｌＤｅｍｏｎｓｔｒａｔｉｏｎＣｅｎｔｅｒｆｏｒＥｘｐｅｒｉｍｅｎｔａｌＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇＥｄｕｃａｔｉｏｎꎬＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉｔｙꎬＪｉｎａｎ２５００６１ꎬＣｈｉｎａ)Ａｂｓｔｒａｃｔ:Ｄｕｅｔｏｔｈｅｄｉｆｆｉｃｕｌｔｉｅｓｏｆｍｅａｓｕｒｅｍｅｎｔｏｆｃｏｎｔａｃｔａｎｇｌｅｗｈｅｎｐｒｅｓｓｉｎｇｓｉｌｉｃａｇｌａｓｓｎａｎｏ￣ｄｒｏｐｌｅｔｉｎＳｉＣｄｉｅｓｕｒｆａｃｅａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅꎬｔｈｅＳｉＯ２/ＳｉＣｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｃｏｎｔａｃｔａｎｇｌｅａｔｄｉｆｆｅｒｅｎｔｔｅｍｐｅｒａｔｕｒｅａｎｄｒｏｕｇｈｓｕｒｆａｃｅａｓｗｅｌｌａｓｔｈｅｓｕｒｆａｃｅｓｔｒｕｃｔｕｒｅｏｆＳｉＯ２ｍｅｌｔｗｅｒｅｓｉｍｕｌａｔｅｄｂｙｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓ.ＵｓｉｎｇｔｈｅｐｒｅｓｓｕｒｅｔｅｎｓｏｒｍｅｔｈｏｄꎬｉｔｉｓｆｏｕｎｄｔｈａｔｔｈｅｓｕｒｆａｃｅｔｅｎｓｉｏｎｏｆＳｉＯ２ｍｅｌｔｓｉｍｕｌａｔｅｄｂｙＭＳ￣Ｑｐｏｔｅｎｔｉａｌｆｕｎｃｔｉｏｎｉｓｃｌｏｓｅｔｏｔｈｅｅｘｐｅｒｉｍｅｎｔａｌｖａｌｕｅ.ＴｈｕｓｔｈｅＭＳ￣ＱｐｏｔｅｎｔｉａｌｃａｎｂｅｐｒｅｆｅｒｒｅｄｉｎｓｉｍｕｌａｔｉｏｎｏｆＳｉＯ２ｈｉｇｈ￣ｔｅｍｐｅｒａｔｕｒｅｓｕｒｆａｃｅｃｈａｒａｃｔｅｒ.ＦｏｒｔｈｅｒｏｕｇｈｎｅｓｓｏｆｎａｎｏｓｃａｌｅｓｕｒｆａｃｅｏｆＳｉＣｄｉｅ.Ｗｈｅｎｔｈｅｒｏｕｇｈｎｅｓｓｆａｃｔｏｒｒｅｘｃｅｅｄｓ１.５ꎬｔｈｅｗｅｔｔｉｎｇｍｏｄｅｃｈａｎｇｅｓｆｒｏｍＷｅｎｚｅｌｔｏＣａｓｓｉｅ￣Ｂａｘｔｅｒ.ＡｔｔｈｉｓｔｉｍｅꎬｔｈｅｃｈａｎｇｅｏｆＲａｈａｓｎｏｓｉｇｎｉｆｉｃａｎｔｉｍｐａｃｔｏｎｔｈｅｃｏｎｔａｃｔａｎｇｌｅꎬａｎｄｔｈｅｒｅｄｕｃｅｄＲｍｒｖａｌｕｅｒｅｓｕｌｔｓｉｎｔｈｅｄｅｃｒｅａｓｅｏｆｃｏｎｔａｃｔａｒｅａｆｒａｃｔｉｏｎｆａｎｄｔｈｅｉｎｃｒｅａｓｅｏｆｃｏｎｔａｃｔａｎｇｌｅ.Ｔｈｅｒｅｆｏｒｅꎬｋｅｅｐｉｎｇｒｇｒｅａｔｅｒｔｈａｎ１.５ｗｈｉｌｅａｐｐｒｏｐｒｉａｔｅｌｙｒｅｄｕｃｉｎｇＲｍｒｖａｌｕｅｉｓｃｏｎｄｕｃｉｖｅｔｏｒｅｄｕｃｉｎｇｓｏｌｉｄ￣ｌｉｑｕｉｄｆｒｉｃｔｉｏｎａｎｄｒｅｄｕｃｉｎｇｔｈｅｓｔｒｉｐｐｉｎｇｆｏｒｃｅｏｎｔｈｅｉｎｔｅｒｆａｃｅｂｅｔｗｅｅｎｆｕｓｅｄｓｉｌｉｃａｗｏｒｋｐｉｅｃｅａｎｄＳｉＣｄｉｅ.ＡｓｔｈｅｔｅｍｐｅｒａｔｕｒｅｉｎｃｒｅａｓｅｓꎬｔｈｅｓｕｒｆａｃｅｓｔｒｕｃｔｕｒｅｏｆＳｉＯ２ｂｅｃｏｍｅｌｏｏｓｅꎬｒｅｓｕｌｔｉｎｇｉｎｉｔｓｃｏｎｔａｃｔａｎｇｌｅｄｅｃｌｉｎｉｎｇｏｎｔｈｅＳｉＣｓｕｒｆａｃｅ.Ｔｈｅｃｈａｎｇｅｒａｔｅｏｆｔｈｅｃｏｎｔａｃｔａｎｇｌｅｉｎｃｒｅａｓｅｓｗｈｅｎｔｅｍｐｅｒａｔｕｒｅｅｘｃｅｅｄｓ２３００Ｋ.Ｉｎｏｒｄｅｒｔｏｒｅｄｕｃｅｔｈｅａｄｈｅｓｉｏｎｏｆｔｈｅｗｏｒｋｐｉｅｃｅｗｉｔｈｔｈｅｄｉｅꎬｔｈｅｍｏｌｄｉｎｇｔｅｍｐｅｒａｔｕｒｅｓｈｏｕｌｄｂｅｂｅｌｏｗ２３００Ｋ.Ｋｅｙｗｏｒｄｓ:ｓｉｌｉｃａｇｌａｓｓꎻｓｉｌｉｃｏｎｃａｒｂｉｄｅꎻｃｏｎｔａｃｔａｎｇｌｅꎻｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓꎻｃｏｍｐｒｅｓｓｉｏｎｍｏｌｄｉｎｇ基金项目:山东省自然科学基金重大基础研究项目(ＺＲ２０１８ＺＢ０５２１)作者简介:吴㊀悠(１９９４￣)ꎬ男ꎬ硕士研究生ꎮ主要从事模具摩擦磨损方面的研究ꎮＥ￣ｍａｉｌ:ｊｏｌｍｕｇｉ＠１６３.ｃｏｍ通讯作者:邹㊀斌ꎬ教授ꎮＥ￣ｍａｉｌ:ｚｂ７８＠ｓｄｕ.ｅｄｕ.ｃｎ９２４㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第３９卷０㊀引㊀言近年来ꎬ微结构光学元件因其在信息通信领域的广泛应用受到越来越多的关注ꎮ模压是制造光学玻璃元件常用的方法之一ꎮ模压过程中ꎬ一方面模具上精准的几何结构复印到了玻璃元件上ꎻ另一方面玻璃元件与模压模具之间的摩擦与粘附造成了模具的磨损ꎬ从而导致模具几何结构精度的丧失ꎮ这些均为模具与工件的固液界面相互接触㊁相对运动作用的结果ꎮ因此ꎬ有必要研究它们的接触特性ꎬ从而对模具结构和模压工艺的设计提供一定的指导ꎮ润湿是能够实现模压的先决条件ꎬ而接触角是表征润湿性的主要参数ꎮ对于理想光滑表面的接触角模型ꎬＹｏｕｎｇ[１]从固㊁液㊁气界面张力平衡的角度建立了经典的杨氏方程ꎮ对于粗糙表面和非均质表面ꎬＷｅｎｚｅｌ[２]和Ｃａｓｓｉｅ[３]等学者在杨氏方程的基础上分别建立了Ｗｅｎｚｅｌ和Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ模型ꎮＷｅｎｚｅｌ润湿模式中ꎬ液体始终完全浸渍粗糙结构波谷中ꎬ即出现所谓 钉扎 现象ꎮ而在模压工艺中ꎬ这一现象增大了工件液相在模具表面流动的阻力ꎬ从而增大了固液摩擦ꎬ使得模具更易磨损ꎮ而Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ润湿模式认为由于粗糙结构波谷中存在气相ꎬ液体无法浸渍其中ꎬ因此是模压比较期望的润湿模式ꎮ在光学玻璃材料中ꎬ石英玻璃的光学性能有其独特之处ꎮ它既可以透过远紫外光谱ꎬ且透射率在同类材料中最优ꎬ又可透过可见光和近红外光谱ꎮ同时ꎬ其机械性能也高于普通玻璃[４]ꎮ目前ꎬ石英玻璃光学元件的制造多采用超精密磨削或是激光刻蚀的方法ꎬ生产效率低ꎬ生产成本高ꎮ而模压方法可以提高加工效率ꎬ实现大规模生产ꎮ然而ꎬ由于石英玻璃软化点温度高达１５００~１６００ħꎬ常用的模具材料如ＷＣ等在此温度下无法正常工作ꎬ而ＳｉＣ热稳定性好ꎬ熔点达２８３０ħ[５]ꎬ故较为适合作为模压石英玻璃的模具材料ꎮ由于模压温度高ꎬ超出了目前接触角测量仪器的工作范围ꎬ并且微结构模具表面粗糙度达到纳米级ꎬ要研究粗糙度对润湿性的影响需要测量纳米尺度微液滴的接触角ꎬ因此试验测定比较困难ꎮ分子动力学方法使微纳液滴高温接触角的模拟及研究其成因机理成为可能ꎮ徐威等[６]通过改变ＬＪ势函数中的作用参数模拟了纳米水滴在不同能量表面上的铺展过程和润湿形态ꎬ模拟结果与经典润湿理论计算得到的结果呈现相似变化趋势ꎮ王龙[７]研究了铜和金液滴在石墨烯和碳纳米管等不同结构基底上的润湿和融合过程ꎬ发现金属液滴的融合受液滴形状和基底结构影响ꎮ由于势函数的限制ꎬ目前对于界面润湿的分子动力学模拟多集中于ＬＪ流体ꎬ如水和液氩等ꎬ而多元素流体较少见于报道ꎮ势函数按多体作用的复杂程度可分为对势和多体势ꎮ对于石英玻璃的模拟ꎬ多体势不能较好地计算Ｓｉ￣Ｏ键的断裂ꎬ因此不利于高温动力学性能的研究[８]ꎮＢｅｅｓｔ等[９]基于石英玻璃经典的ＢＭＨ势提出了ＢＫＳ势ꎬ并运用第一性原理方法结合实验数据拟合了参数ꎮＳｕｎｄａｒａｒａｍａｎ等[１０]使用ＢＫＳ势预测了石英玻璃的力学性能ꎬ发现当短程和长程截止半径分别为５.５Å和１０Å时模拟的石英玻璃结构更符合实际ꎮＤｅｍｉｒａｌｐ等[１１]首先将Ｍｏｒｓｅ势与电荷平衡法(ＱＥｑ)相结合ꎬ建立了ＭＳ￣Ｑ力场ꎬ并研究了石英玻璃在压力变化过程中的相变ꎮ丁元法等[１２]比较了ＢＫＳ与ＭＳ￣Ｑ模型下石英玻璃的高温扩散特性ꎬ认为计算高温下石英玻璃的扩散传输性能可优先选择ＭＳ￣Ｑ力场ꎬ但并未比较其表面特性ꎮ从以上文献可以看出ꎬＢＫＳ和ＭＳ￣Ｑ是石英玻璃分子动力学模拟中常用的对势ꎮ其中ꎬＢＫＳ势从低温到高温的较大温度范围均具有较好性能ꎬ而ＭＳ￣Ｑ势在高温下的传输性能要优于ＢＫＳ势ꎮ目前对于石英玻璃高温表面特性的模拟的报道较为少见ꎬ因此仍需要对两种势函数性能的优劣进行比较ꎮＨｏｓｓｅｉｎｉ等[１３]研究了不同形貌的疏水表面上的水滴行为ꎬ发现表面形貌㊁柱高度㊁空隙率和沉积角是影响表面疏水性的主要参数ꎮ因此ꎬ本模拟在ＳｉＣ表面构建了纳米方柱阵列ꎬ并分别使用粗糙度评定参数Ｒａ和Ｒｍｒ表示柱高和空隙率ꎬ研究了纳米级表面粗糙结构对面向高温模压的ＳｉＯ２/ＳｉＣ接触角的影响ꎮ本文使用分子动力学方法ꎬ对比了分别采用ＢＫＳ和ＭＳ￣Ｑ势函数计算的ＳｉＯ２熔体高温表面张力ꎮ模拟了不同模压温度和ＳｉＣ模具表面粗糙结构ＳｉＯ２的高温接触角ꎬ研究了微尺度下的高温界面润湿特征和ＳｉＯ２熔体表面层结构特点ꎬ本研究的结构框图如图１所示ꎮ１㊀模拟方法和模型１.１㊀界面张力的计算为了保证成形精度并减小工件与模具的粘附ꎬ光学玻璃模压温度一般选择在转变点温度到软化点温度第３期吴㊀悠:ＳｉＣ模具高温模压石英玻璃物相接触角的分子动力学模拟９２５㊀之间[１４]ꎬ故选择石英玻璃实际软化点附近温度１９００Ｋ作为模拟温度ꎮＳｉＯ２表面张力模拟系统如图２所示ꎮＳｉＯ２熔体表面模型的建立方法是在模拟盒子中随机加入８００个Ｓｉ原子和１６００个Ｏ原子ꎬ使其密度约为２.２ｇ/ｃｍ３ꎮ随后在５０００Ｋ下驰豫２００ｐｓ以消除初始构型的影响ꎬ并以１００Ｋ/２０ｐｓ的速度降温至１９００Ｋꎮ最后在ｘ轴方向模型两边各添加一厚度为２０Å的真空层ꎬ以避免周期性边界的影响ꎮ面向高温模压的ＳｉＯ２/ＳｉＣ界面张力模拟系统如图３(ｃ)所示ꎬ其中ＳｉＣ是由金刚石结构的β￣ＳｉＣ原胞排列而成ꎮ分别将ＳｉＯ２和ＳｉＣ单独在１９００Ｋ下驰豫２００ｐｓꎬ然后将它们添加进同一模拟盒子中ꎬ使ＳｉＯ２与ＳｉＣ{１００}表面接触并对整个体系进行驰豫ꎮ图１㊀基于分子动力学的ＳｉＣ模具高温模压石英玻璃的物相接触角模拟研究关系框图Ｆｉｇ.１㊀ＳｔｕｄｙｒｅｌａｔｉｏｎｓｈｉｐｏｆｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｃｏｎｔａｃｔａｎｇｌｅｏｆｍｏｌｄｅｄｏｐｔｉｃａｌｇｌａｓｓｉｎＳｉＣｄｉｅｂａｓｅｄｏｎｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓ图２㊀ＳｉＯ２熔体表面张力模拟计算体系Ｆｉｇ.２㊀ＳｉｍｕｌａｔｉｏｎｓｙｓｔｅｍｏｆＳｉＯ２ｍｅｌｔｓｕｒｆａｃｅｔｅｎｓｉｏｎ图３㊀ＳｉＯ２/ＳｉＣ高温界面张力模拟计算体系Ｆｉｇ.３㊀ＳｉｍｕｌａｔｉｏｎｓｙｓｔｅｍｏｆＳｉＯ２/ＳｉＣｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｉｎｔｅｒｆａｃｅｔｅｎｓｉｏｎ㊀㊀表面与界面张力的计算均采用压力张量法[１５]ꎬγ＝１２ʏＬｘ２－Ｌｘ２[ＰＮ(ｘ)－ＰＴ(ｘ)]ｄｘ(１)式中ꎬγ表示表面张力ꎻＬｘ为模拟体系在ｘ方向的长度ꎻ因子１/２是由于模拟系统有两个界面ꎻＰＮ与ＰＴ分别为系统界面法向和切向压力张量分量ꎮＰＮ(ｘ)＝ρｋＢＴ－１Ｖðｉ<ｊｘ２ｉｊｒｉｊｄＵ(ｒｉｊ)ｄｒｉｊ[](２)９２６㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第３９卷ＰＴ(ｘ)＝ρｋＢＴ－１Ｖðｉ<ｊｙ２ｉｊ－ｚ２ｉｊ２ｒｉｊｄＵ(ｒｉｊ)ｄｒｉｊ[](３)式中ꎬｋＢ为玻尔兹曼常数ꎻＶ为模拟盒子体积ꎻＵ表示势函数ꎻρ为液体密度ꎻＴ为温度ꎻｒ为原子间距ꎬｘ㊁ｙ㊁ｚ为其在三个坐标轴方向的分量ꎮ为了比较不同势函数模拟界面张力的可靠性ꎬ在模拟中ꎬＳｉＯ２原子间的相互作用先后用ＢＫＳ[１０]和ＭＳ￣Ｑ[１１]势函数进行表征如下ꎬ势函数参数见表１ꎮＵＢｉｊ＝ｑｉｑｊｅ２ｒｉｊ＋Ａｉｊｅ－ｒｉｊρ－Ｃｉｊｒ６ｉｊ(４)ＵＭｉｊ＝ｑｉｑｊｅ２ｒｉｊ＋Ｄ０[ｅ－２α(ｒｉｊ－ｒ０)－２ｅ－α(ｒｉｊ－ｒ０)](５)式中ꎬｑ表示电荷量ꎻＡ㊁Ｃ㊁Ｄ均为与相互作用强度有关的参数ꎻα为与平衡距离有关的参数ꎮ表１㊀ＳｉＯ２势函数参数Ｔａｂｌｅ１㊀ＰａｒａｍｅｔｅｒｓｏｆｐｏｔｅｎｔｉａｌｓｆｏｒＳｉＯ２ＰａｉｒＢＫＳＡｉｊ/(ｋｃａｌ ｍｏｌ－１)ρ/ÅＣｉｊ/(ｋｃａｌ ｍｏｌ－１ Å６)ＭＳ￣ＱＤ０/(ｋｃａｌ ｍｏｌ－１)α/Å－１ｒ０/ÅＳｉ￣Ｓｉ￣￣￣０.１７７３２.０４４３.７６０Ｏ￣Ｏ３２０２５.７９９８０.３６２３４０３５.５８７５０.５３６３１.３７３３.７９１Ｓｉ￣Ｏ４１５１７５.６４２９０.２０５２３０７９.４５５４４５.９９７０２.６５２１.６２８㊀㊀ＳｉＣ原子间的相互作用使用ｔｅｒｓｏｆｆ势函数表征ꎮ由于ＳｉＯ２/ＳｉＣ界面间为范德华作用ꎬ因此使用ＬＪ势函数表征ꎬ其参数来自于ＵＦＦ力场[１６]ꎬ如表２所示ꎮ表２㊀ＳｉＯ２/ＳｉＣ势函数参数Ｔａｂｌｅ２㊀ＰａｒａｍｅｔｅｒｓｏｆｐｏｔｅｎｔｉａｌｆｏｒＳｉＯ２/ＳｉＣｉｎｔｅｒａｃｔｉｏｎＰａｉｒε/(ｋｃａｌ ｍｏｌ－１)σ/ÅＳｉ￣Ｓｉ０.４０２３.８２６Ｏ￣Ｓｉ０.１５５３３.４７２３Ｓｉ￣Ｃ０.２０５３.６２８Ｏ￣Ｃ０.０７９３３.２７４５㊀㊀模拟过程中ꎬ模拟盒子三个方向均为周期性边界ꎮＢＫＳ势函数Ｓｉ和Ｏ原子所带电荷分别为＋２.４ｅ㊁－１.２ｅꎬ截断半径为５.５ÅꎻＭＳ￣Ｑ势函数Ｓｉ和Ｏ原子所带电荷分别为＋１.３１８ｅ㊁－０.６５９ｅꎬ截断半径为９Åꎮ静电力的计算采用ＰＰＰＭ(Ｐａｒｔｉｃｌｅ￣ＰａｒｔｉｃｌｅＰａｒｔｉｃｌｅ￣Ｍｅｓｈ)方法且精度为１０－５ꎬ截断半径为１０Åꎮ时间步长为１ｆｓꎮ模拟均在正则系综(ＮＶＴ)下进行ꎬ调温使用Ｎｏｓé￣Ｈｏｏｖｅｒ方法ꎮ１.２㊀接触角的模拟图４㊀面向高温模压的ＳｉＯ２/ＳｉＣ接触角模拟系统Ｆｉｇ.４㊀ＳｉｍｕｌａｔｉｏｎｓｙｓｔｅｍｏｆＳｉＯ２/ＳｉＣｃｏｎｔａｃｔａｎｇｌｅｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｏｌｄｉｎｇ在模拟系统中ＳｉＯ２与ＳｉＣ分别为液相和固相ꎬ其中ꎬＳｉＣ基底为ＳｉＣ单胞排列而成的超晶胞ꎬ对其作出三点假设:(１)假设ＳｉＣ表面为不存在缺陷的理想表面ꎻ(２)由于ＳｉＣ不同晶面表面能相差较小ꎬ假设其{１００}晶面为与ＳｉＯ２相接触的表面ꎻ(３)假设ＳｉＯ２熔体液滴为理想的球形ꎮ接触角的模拟系统如图４所示ꎬ首先在半径２.３４８Å的球体区域随机添加１２００个Ｓｉ原子和２４００个Ｏ原子ꎬ随后在５０００Ｋ下驰豫２００ｐｓ并以１００Ｋ/２０ｐｓ的速度降温至１９００Ｋ得到模拟所用的ＳｉＯ２液滴模型ꎮ最后将ＳｉＯ２和ＳｉＣ添加进同一模拟盒子ꎬｘ㊁ｙ方向使用周期性边界ꎬｚ方向使用固定和镜像边界ꎬ其他第３期吴㊀悠:ＳｉＣ模具高温模压石英玻璃物相接触角的分子动力学模拟９２７㊀设置与上一节相同ꎮ图５㊀微结构阵列模具表面多尺度形貌示意图Ｆｉｇ.５㊀Ｍｕｌｔｉｓｃａｌｅｓｕｒｆａｃｅｔｏｐｏｇｒａｐｈｙｏｆｍｉｃｒｏ￣ｓｔｒｕｃｔｕｒｅａｒｒａｙｄｉｅ为了研究纳米级表面粗糙结构对接触角的影响ꎬ采用文献[１３]的方法构建了方柱形阵列ＳｉＣ壁面ꎮ其结构如图５所示ꎮＷｅｎｚｅｌ[２]和Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ[３]模型可用式(６)㊁(７)表示:ｃｏｓθＷ＝ｒｃｏｓθＹ(６)ｃｏｓθＣ＝ｆｃｏｓθＹ＋ｆ－１(７)式中ꎬθＹ为本征接触角ꎻθＷ与θＣ为Ｗｅｎｚｅｌ和Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ模型接触角ꎻｒ为粗糙度因子ꎬ表示表面的实际面积与表观面积之比ꎻｆ为接触面积分数ꎬ表示液滴与基底实际接触的面积和基底表观面积之比ꎮｒ与ｆ可用粗糙度评定参数表示为ｒ＝１＋８ＲｍｒＲａＳｍ(８)ｆ＝Ｒｍｒ２(９)式中ꎬＲａ为轮廓算数平均偏差ꎬＲｍｒ为轮廓支承长度率ꎬＳｍ为轮廓微观不平度的平均间距ꎮ模拟中若Ｒｍｒ㊁Ｓｍ取恒值ꎬ则Ｒａ取０.２５㊁０.５㊁１㊁１.５倍晶格参数ꎬ分别对应ｒ值为１.５㊁２.０㊁３.０㊁４.０ꎻ若Ｒａ取恒值ꎬ改变柱间距为２㊁１.５㊁１㊁０.５倍晶格参数使Ｒｍｒ取０.３３㊁０.４０㊁０.５０㊁０.６７ꎬ分别对应ｆ值为０.１１㊁０.１６㊁０.２５㊁０.４４ꎮ２㊀模拟结果与讨论２.１㊀界面张力图６为１９００Ｋ下ＢＫＳ与ＭＳ￣Ｑ模型中ＳｉＯ２熔体表面张力随时间的演化ꎮ由于使用压力张量法时系统需要较长时间稳定ꎬ模拟连续进行了２０ｎｓꎮ为了降低模拟初期结构不稳定的影响ꎬ在计算累计平均值时采用最后１０ｎｓ数据ꎮＢＫＳ与ＭＳ￣Ｑ势函数的计算结果分别为０.４１０Ｎ/ｍ和０.３９０Ｎ/ｍꎮ由文献[１７]可知ꎬＳｉＯ２在１９００Ｋ下的实际表面张力应为０.３０２Ｎ/ｍ左右ꎮ考虑到模拟本身的准确性以及实际实验过程中ꎬ氧分子等充当表面活性剂降低了测定的表面张力值ꎬ因此模拟值高出实验值０.０７~０.１１Ｎ/ｍ左右是可接受的[１８]ꎮ可以看出ＭＳ￣Ｑ势函数的模拟结果比ＢＫＳ势函数更为接近实验值ꎮ图６㊀ＢＫＳ势函数与ＭＳ￣Ｑ势函数下ＳｉＯ２熔体表面张力演化Ｆｉｇ.６㊀ＥｖｏｌｕｔｉｏｎｏｆＳｉＯ２ｍｅｌｔｓｕｒｆａｃｅｔｅｎｓｉｏｎｕｓｉｎｇＢＫＳｐｏｔｅｎｔｉａｌａｎｄＭＳ￣Ｑｐｏｔｅｎｔｉａｌ图７为两种不同势函数模拟的面向模压的ＳｉＯ２/ＳｉＣ高温界面张力演化图ꎮ界面张力系统达到稳定时间相对较短ꎬ因此模拟时间设为１５ｎｓꎬ取最后４.５ｎｓ时间段的数据计算平均值ꎮ从图中可见ꎬＢＫＳ和ＭＳ￣Ｑ势函数的模拟结果分别为０.８４６Ｎ/ｍ和０.６８２Ｎ/ｍꎮ同时ꎬ计算了两种表面模型的一维密度分布和径向分布函数(ＲａｄｉａｌＤｉｓｔｒｉｂｕｔｉｏｎＦｕｎｃｔｉｏｎꎬＲＤＦ)ꎮ图８(ａ)为模型中心至模拟盒子边缘的密度分布ꎬＢＫＳ与ＭＳ￣Ｑ模型的表面均存在类似汽液共存界面的低密度相ꎬ其厚度分别为４Å与６ÅꎮＢＫＳ模型内部的密度约为９２８㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第３９卷２.６９ｇ/ｃｍ３ꎬ大于ＭＳ￣Ｑ的２.２５ｇ/ｃｍ３ꎮ这说明ＢＫＳ表面模型的密度大于ＭＳ￣Ｑ模型ꎬ因此原子间距要小于ＭＳ￣Ｑ模型ꎬ具有更强的原子间作用力ꎬ从而具有更大的表面张力ꎮ图８(ｂ)中ＲＤＦ的计算结果也支持了这一解释ꎮＲＤＦ图中前三个峰代表Ｏ￣Ｏ㊁Ｓｉ￣Ｏ㊁Ｓｉ￣Ｓｉ原子对的第一近邻ꎬ峰值点的横坐标即原子对的键长ꎬ其数值如图８(ｂ)所示ꎬＭＳ￣Ｑ模型中数量较多且强度较大的Ｓｉ￣Ｏ㊁Ｏ￣Ｏ键长均大于ＢＫＳ模型ꎬ从而导致其表面张力小于ＢＫＳ模型ꎮ综上所述ꎬ高温模压时ＳｉＯ２表面性质的模拟可优先选择ＭＳ￣Ｑ势函数ꎮ图７㊀面向高温模压的ＳｉＯ２/ＳｉＣ界面张力演化过程Ｆｉｇ.７㊀ＥｖｏｌｕｔｉｏｎｏｆＳｉＯ２/ＳｉＣｉｎｔｅｒｆａｃｅｔｅｎｓｉｏｎｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｏｌｄｉｎｇ图８㊀使用ＢＫＳ与ＭＳ￣Ｑ势函数的ＳｉＯ２表面结构对比Ｆｉｇ.８㊀ＣｏｍｐａｒｉｓｏｎｏｆＳｉＯ２ｓｕｒｆａｃｅｓｔｒｕｃｔｕｒｅｕｓｉｎｇＢＫＳａｎｄＭＳ￣Ｑｐｏｔｅｎｔｉａｌ２.２㊀表面粗糙结构对接触角的影响液滴在理想光滑表面上的接触角称为本征接触角ꎮ由于微纳尺度下液滴表面存在一定的密度和压力涨落ꎬ为了获得具有统计学意义的接触角值ꎬ在处理数据时采用等密度拟合曲线法[１９]ꎮ最后得到面向高温模压的ＳｉＯ２/ＳｉＣ的本征接触角为１１９.２５ʎꎮ根据杨氏方程[１]ꎬ可以利用上节模拟得到的界面张力对本征接触角进行检验ꎮｃｏｓθ＝γｓｖ－γｓｌγｌｖ(１０)式中ꎬγｓｖ表示固￣气界面能ꎻγｓｌ与γｌｖ分别表示固￣液界面能和气￣液界面能ꎬ它们在数值上与固￣液界面张力和液体表面张力相等ꎮ由上节可知ꎬγｓｌ和γｌｖ的值分别为０.６８２Ｎ/ｍ和０.３９０Ｎ/ｍꎮ由于本模拟中采用的ＳｉＯ２/ＳｉＣ相互作用参数来自ＵＦＦ力场ꎬ因此选择文献[２０]中使用ＵＦＦ力场算得的ＳｉＣ{１００}晶面表面能数值０.５０２Ｎ/ｍ代入式(１０)ꎮ最终得到的本征接触角理论值为１１７.４９ʎꎬ与模拟数值差别不大ꎮ图９是ＳｉＯ２熔体在具有不同粗糙度因子的ＳｉＣ模具表面上接触角的模拟ꎬ从图中可见ꎬ接触角总体值在１３５ʎ左右波动ꎮ接触角变化不大则表明固液相互作用能较为稳定ꎬ但图９(ｂ)显示ꎬ在ｒ＝１.５时固液相互作用能较大ꎮ由图１０可以看出ꎬ当粗糙度因子ｒ＝１.５时ꎬＳｉＯ２熔体浸润了沟槽ꎬ出现 钉扎 现象ꎬ此时润湿第３期吴㊀悠:ＳｉＣ模具高温模压石英玻璃物相接触角的分子动力学模拟９２９㊀接近于Ｗｅｎｚｅｌ状态ꎮ 钉扎 现象增强了固液界面的摩擦ꎬ液滴的铺展需要克服更大的能垒ꎬ因此虽然固液相互作用能较大但并未使液滴接触角减小ꎻｒ>１.５时ꎬＳｉＯ２均处于Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ润湿状态ꎬ因此接触角不再受粗糙度因子变化的影响ꎮ从Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ状态到Ｗｅｎｚｅｌ状态的过渡称为润湿转变ꎮ润湿转变可以通过施加压力实现ꎬ但临界转变压力会随着纳米柱的高度减小而减小[２１]ꎻ当其减小到一定程度ꎬ就可能仅仅依靠系统压力实现润湿转变ꎮ本研究中ꎬ当ｒ>１.５时系统压力无法使液滴保持Ｗｅｎｚｅｌ状态ꎬ因此转变为Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ状态ꎻ而此状态下ꎬ界面的固液相互作用比Ｗｅｎｚｅｌ状态更低ꎬ液滴在固体表面的扩散系数变小[２２]ꎬ说明此时ＳｉＯ２熔体在剪切作用下更易在ＳｉＣ模具表面滑移ꎬ从而导致粘性摩擦作用较小ꎮ图９㊀ＳｉＣ模具表面粗糙度对ＳｉＯ２熔体液滴接触角和两者相互作用能的影响Ｆｉｇ.９㊀ＥｆｆｅｃｔｏｆＳｉＣｄｉｅｒｏｕｇｈｎｅｓｓｏｎｃｏｎｔａｃｔａｎｇｌｅｏｆＳｉＯ２ｍｅｌｔｄｒｏｐｌｅｔａｎｄｉｎｔｅｒａｃｔｉｏｎｅｎｅｒｇｙ图１０㊀ＳｉＣ模具表面粗糙度对ＳｉＯ２熔体液滴接触状态的影响Ｆｉｇ.１０㊀ＥｆｆｅｃｔｏｆＳｉＣｄｉｅｒｏｕｇｈｎｅｓｓｏｎｃｏｎｔａｃｔｓｔａｔｅｏｆＳｉＯ２ｍｅｌｔｄｒｏｐｌｅｔ图１１㊀接触面积分数对面向高温模压的ＳｉＯ２/ＳｉＣ接触状态的影响Ｆｉｇ.１１㊀ＥｆｆｅｃｔｏｆｃｏｎｔａｃｔａｒｅａｆｒａｃｔｉｏｎｏｎＳｉＯ２/ＳｉＣｃｏｎｔａｃｔｓｔａｔｅｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｏｌｄｉｎｇ图１２㊀接触面积分数对面向高温模压的ＳｉＯ２/ＳｉＣ接触角和相互作用能的影响Ｆｉｇ.１２㊀ＥｆｆｅｃｔｏｆｃｏｎｔａｃｔａｒｅａｆｒａｃｔｉｏｎｏｎＳｉＯ２/ＳｉＣｃｏｎｔａｃｔａｎｇｌｅａｎｄｉｎｔｅｒａｃｔｉｏｎｅｎｅｒｇｙｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｏｌｄｉｎｇ９３０㊀陶㊀瓷硅酸盐通报㊀㊀㊀㊀㊀㊀第３９卷图１１为粗糙度因子ｒ>１.５时ＳｉＣ模具表面接触面积分数对ＳｉＯ２熔体液滴接触状态的影响ꎬ此时ＳｉＯ２始终呈现Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ润湿状态ꎬ液滴随接触面积分数的增大逐渐在ＳｉＣ表面铺展ꎮ图１２(ａ)对比了模拟接触角和理论接触角ꎬ虽然两者存在一定误差ꎬ但其都随着接触面积分数的增大而减小ꎻ同时图１２(ｂ)显示接触角越小ꎬＳｉＯ２/ＳｉＣ高温模压界面具有越强的相互作用ꎮ表面粘着力和热应力是脱模力的两个组成部分[２３]ꎬ减小轮廓支承长度率即减小了ＳｉＯ２与ＳｉＣ模具界面的实际接触面积ꎬ从而能减小工件和模具之间的表面粘着力ꎮ而Ｃａｓｓｉｅ￣Ｂａｘｔｅｒ润湿模式无 钉扎 现象ꎬ减小了工件和模具的传热面积ꎬ在一定程度上减小了热应力ꎮ因此适当减小Ｒｍｒ值可以降低以及工件与模具之间的脱模力ꎬ从而减小模具磨损ꎬ提高寿命ꎮ同时也缩减了模具制造过程中抛光工序的工作量ꎮ２.３㊀温度对接触角的影响图１３㊀面向高温模压的ＳｉＯ２/ＳｉＣ接触角与温度的关系Ｆｉｇ.１３㊀ＲｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎＳｉＯ２/ＳｉＣｃｏｎｔａｃｔａｎｇｌｅａｎｄｔｅｍｐｅｒａｔｕｒｅｆｏｒｈｉｇｈｔｅｍｐｅｒａｔｕｒｅｍｏｌｄｉｎｇ图１３为接触面积分数为０.２５时温度对面向高温模压的ＳｉＯ２/ＳｉＣ接触角的影响ꎮ从图可见ꎬ接触角值随温度的增大而减小ꎬ说明温度升高ＳｉＯ２的表面张力减小ꎻ当温度高于２３００Ｋ时ꎬ接触角的变化较大ꎬ这是因为使用ＭＳ￣Ｑ势函数模型的ＳｉＯ２自扩散激活温度约为２３００Ｋ左右[１２]ꎮ自扩散激活温度可以视作石英玻璃的软化点温度ꎬ在此温度附近ꎬ石英玻璃的结构发生较大变化ꎬ松动和新生的化学键均大大增加[２４]ꎮ图１４(ａ)是不同温度下ＳｉＯ２熔体表面的结构特点ꎬ由图可见ꎬＳｉＯ２熔体表面存在一个等密度层ꎻ在等密度层外部ꎬ密度随温度升高而增大ꎻ在等密度层内部ꎬ密度随温度升高而减小ꎻ这意味着ＳｉＯ２熔体内部的原子在高温作用下逐渐向外扩散ꎬ这种密度梯度的减小使ＳｉＯ２表面结构更加松散ꎬ减小了其表面张力ꎮ图１４(ｂ)还表明ꎬ温度对ＳｉＯ２熔体表面原子化学键的键长并未产生较大影响ꎬ但随着温度升高ꎬ各化学键对应的峰值依次减小ꎬ表明表面层原子的无序程度增加ꎮ同时ꎬ对比图８(ｂ)可以发现ꎬ表面层中Ｓｉ￣Ｓｉ对应的峰值变得较为微弱甚至消失ꎬ这说明在表面层硅原子数量较少ꎬ而氧原子大量聚集ꎬＯ￣Ｏ键的强度远小于Ｓｉ￣Ｏ键强度ꎬ这可能是ＳｉＯ２表面张力随温度减小的另一个原因ꎮ图１４㊀不同温度下ＳｉＯ２熔体表面结构特点Ｆｉｇ.１４㊀ＳｕｒｆａｃｅｓｔｒｕｃｔｕｒｅｏｆＳｉＯ２ｍｅｌｔｉｎｄｉｆｆｅｒｅｎｔｔｅｍｐｅｒａｔｕｒｅ３㊀结㊀论采用分子动力学方法模拟了ＳｉＯ２熔体的界面结构ꎬ将ＳｉＣ模具纳米级表面理想化为纳米方柱阵列ꎬ研㊀第３期吴㊀悠:ＳｉＣ模具高温模压石英玻璃物相接触角的分子动力学模拟９３１究了粗糙度和温度对面向模压的ＳｉＯ２/ＳｉＣ高温接触角的影响ꎬ得到以下结论:(１)使用ＭＳ￣Ｑ势函数模拟的ＳｉＯ２熔体表面张力比ＢＫＳ势函数计算的结果与实验值更为接近ꎬ因此模拟ＳｉＯ２高温熔体的表面性质使用ＭＳ￣Ｑ势函数更为合理ꎮ(２)在１９００Ｋ的模压温度下ꎬ当粗糙度因子ｒ>１.５时ꎬＲａ的变化对接触角值无明显影响ꎮＲｍｒ值减小使得接触面积分数ｆ减小ꎬ接触角值随之增大ꎮ此时润湿模式从Ｗｅｎｚｅｌ转变为Ｃａｓｓｉｅ￣Ｂａｘｔｅｒꎬ减小了工件￣模具之间的摩擦ꎮ由于热应力和界面粘着力的减小ꎬ石英玻璃光学元件模压后的脱模力将会降低ꎮ同时ꎬ由于降低了Ｒｍｒ值的要求ꎬＳｉＣ模具加工过程中抛光工序的工作量也相应得到了减小ꎮ(３)面向高温模压的ＳｉＯ２/ＳｉＣ的接触角随模压温度升高而减小ꎮ当模压温度超过２３００Ｋ时ꎬ接触角变化率显著增大ꎮ因此模压温度选择在２３００Ｋ以下可以降低模压时模具因玻璃熔体的粘附造成的磨损ꎮ参考文献[１]㊀ＹｏｕｎｇＴＨ.Ａｎｅｓｓａｙｏｎｔｈｅｃｏｈｅｓｉｏｎｏｆｌｉｑｕｉｄｓ[Ｊ].Ｐｈｉｌ.Ｔｒａｎｓ.Ｒｏｙ.Ｓｏｃ.Ｌｏｎｄｏｎꎬ１８０５ꎬ９５:６５￣８７.[２]㊀ＷｅｎｚｅｌＲＮ.Ｒｅｓｉｓｔａｎｃｅｏｆｓｏｌｉｄｓｕｒｆａｃｅｓｔｏｗｅｔｔｉｎｇｂｙｗａｔｅｒ[Ｊ].Ｉｎｄ.Ｅｎｇ.Ｃｈｅｍ.ꎬ１９３６ꎬ２８:９８８￣９４.[３]㊀ＣａｓｓｉｅＡＢＤꎬＢａｘｔｅｒＳ.Ｗｅｔｔａｂｉｌｉｔｙｏｆｐｏｒｏｕｓｓｕｒｆａｃｅｓ[Ｊ].Ｔｒａｎｓ.Ｆａｒａｄａｙ.Ｓｏｃ.ꎬ１９４４ꎬ４０:５４６￣５１.[４]㊀陈㊀光.新材料概论[Ｍ].北京:科学出版社ꎬ２００３:４６￣４８.[５]㊀和丽芳.纳米碳化硅材料的制备及应用[Ｄ].太原:山西大学ꎬ２０１１.[６]㊀徐㊀威ꎬ兰㊀忠ꎬ彭本利ꎬ等.微液滴在不同能量表面上润湿状态的分子动力学模拟[Ｊ].物理学报ꎬ２０１６(２１):２１６８０１.[７]㊀王㊀龙.金属液滴在碳纳米材料表面的润湿与融合[Ｄ].济南:山东大学ꎬ２０１７.[８]㊀ＤｉｎｇＹꎬＺｈａｎｇＹꎬＺｈａｎｇＦꎬｅｔａｌ.ＭｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓｓｔｕｄｙｏｆｔｈｅｓｔｒｕｃｔｕｒｅｉｎｖｉｔｒｅｏｕｓｓｉｌｉｃａｗｉｔｈＣＯＭＰＡＳＳｆｏｒｃｅｆｉｅｌｄａｔｅｌｅｖａｔｅｄｔｅｍｐｅｒａｔｕｒｅｓ[Ｃ].ＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅＦｏｒｕｍ.２００７.[９]㊀ＢｅｅｓｔＢＷＨＶꎬＫｒａｍｅｒＧＪꎬＳａｎｔｅｎＲＡＶ.Ｆｏｒｃｅｆｉｅｌｄｓｆｏｒｓｉｌｉｃａｓａｎｄａｌｕｍｉｎｏｐｈｏｓｐｈａｔｅｓｂａｓｅｄｏｎａｂｉｎｉｔｉｏｃａｌｃｕｌａｔｉｏｎｓ[Ｊ].ＰｈｙｓｉｃａｌＲｅｖｉｅｗＬｅｔｔｅｒｓꎬ１９９０ꎬ６４(１６):１９５５.[１０]㊀ＳｕｎｄａｒａｒａｍａｎＳꎬＣｈｉｎｇＷＹꎬＨｕａｎｇＬ.Ｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｓｉｌｉｃａｇｌａｓｓｐｒｅｄｉｃｔｅｄｂｙａｐａｉｒｗｉｓｅｐｏｔｅｎｔｉａｌｉｎｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓｓｉｍｕｌａｔｉｏｎｓ[Ｊ].ＪｏｕｒｎａｌｏｆＮｏｎ￣ＣｒｙｓｔａｌｌｉｎｅＳｏｌｉｄｓꎬ２０１６ꎬ４４５￣４４６:１０２￣１０９.[１１]㊀ＤｅｍｉｒａｌｐＥꎬＣａｇｉｎꎬＴａｈｉｒꎬＧｏｄｄａｒｄＷＡ.Ｍｏｒｓｅｓｔｒｅｔｃｈｐｏｔｅｎｔｉａｌｃｈａｒｇｅｅｑｕｉｌｉｂｒｉｕｍｆｏｒｃｅｆｉｅｌｄｆｏｒｃｅｒａｍｉｃｓ:ａｐｐｌｉｃａｔｉｏｎｔｏｔｈｅｑｕａｒｔｚ￣ｓｔｉｓｈｏｖｉｔｅｐｈａｓｅｔｒａｎｓｉｔｉｏｎａｎｄｔｏｓｉｌｉｃａｇｌａｓｓ[Ｊ].ＰｈｙｓｉｃａｌＲｅｖｉｅｗＬｅｔｔｅｒｓꎬ１９９９ꎬ８２(８):１７０８￣１７１１.[１２]㊀丁元法ꎬ张㊀跃ꎬ张凡伟ꎬ等.石英玻璃高温分子动力学模拟中的势函数[Ｊ].物理化学学报ꎬ２００８ꎬ２４(５):７８８￣７９２.[１３]㊀ＨｏｓｓｅｉｎｉＳꎬＳａｖａｌｏｎｉＨꎬＳｈａｈｒａｋｉＭＧ.Ｉｎｆｌｕｅｎｃｅｏｆｓｕｒｆａｃｅｍｏｒｐｈｏｌｏｇｙａｎｄｎａｎｏ￣ｓｔｒｕｃｔｕｒｅｏｎｈｙｄｒｏｐｈｏｂｉｃｉｔｙ:Ａｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓａｐｐｒｏａｃｈ[Ｊ].ＡｐｐｌｉｅｄＳｕｒｆａｃｅＳｃｉｅｎｃｅꎬ２０１９ꎬ４８５:５３６￣５４６.[１４]㊀周书强.小口径非球面玻璃透镜的模压仿真及实验研究[Ｄ].长沙:湖南大学ꎬ２０１６.[１５]㊀ＨｅｒｄｅｓＣꎬＥｒｖｉｋＡꎬＭｅｊíａꎬｅｔａｌ.Ｐｒｅｄｉｃｔｉｏｎｏｆｔｈｅｗａｔｅｒ/ｏｉｌｉｎｔｅｒｆａｃｉａｌｔｅｎｓｉｏｎｆｒｏｍｍｏｌｅｃｕｌａｒｓｉｍｕｌａｔｉｏｎｓｕｓｉｎｇｔｈｅｃｏａｒｓｅ￣ｇｒａｉｎｅｄＳＡＦＴ￣γＭｉｅｆｏｒｃｅｆｉｅｌｄ[Ｊ].ＦｌｕｉｄＰｈａｓｅＥｑｕｉｌｉｂｒｉａꎬ２０１８ꎬ４７６:９￣１５.[１６]㊀ＲａｐｐｅＡＫꎬＣａｓｅｗｉｔＣＪꎬＣｏｌｗｅｌｌＫＳꎬｅｔａｌ.ＵＦＦꎬａｆｕｌｌｐｅｒｉｏｄｉｃｔａｂｌｅｆｏｒｃｅｆｉｅｌｄｆｏｒｍｏｌｅｃｕｌａｒｍｅｃｈａｎｉｃｓａｎｄｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓｓｉｍｕｌａｔｉｏｎｓ[Ｊ].ＪｏｕｒｎａｌｏｆｔｈｅＡｍｅｒｉｃａｎＣｈｅｍｉｃａｌＳｏｃｉｅｔｙꎬ１９９２ꎬ１１４(２５):１００２４￣１００３５.[１７]㊀ＷｕＣꎬＣｈｅｎＧ.ＣｏｍｐｕｔａｔｉｏｎａｌｍｏｄｅｌｏｎｓｕｒｆａｃｅｔｅｎｓｉｏｎｏｆＣａＯ￣ＭｎＯ￣ＳｉＯ２ｓｌａｇｓｙｓｔｅｍ[Ｊ].ＨｏｔＷｏｒｋｉｎｇＴｅｃｈｎｏｌｏｇｙꎬ２０１４ꎬ４３(１９):５８￣６２. [１８]㊀ＢｅｌａｓｈｃｈｅｎｋｏＤＫꎬＯｓｔｒｏｖｓｋｉｉＯＩ.Ｃｏｍｐｕｔｅｒｓｉｍｕｌａｔｉｏｎｏｆｓｍａｌｌｎｏｎｃｒｙｓｔａｌｌｉｎｅｓｉｌｉｃａｃｌｕｓｔｅｒｓ[Ｊ].ＩｎｏｒｇａｎｉｃＭａｔｅｒｉａｌｓꎬ２００２ꎬ３８(９):９１７￣９２１. [１９]㊀王宝和ꎬ李㊀群.接触角的研究现状及其在凝胶干燥中的作用[Ｊ].干燥技术与设备ꎬ２０１４ꎬ１２(１):３９￣４６.[２０]㊀罗晓光.ＺｒＢ２/ＳｉＣ复合材料界面结构的分子动力学模拟[Ｄ].哈尔滨:哈尔滨工业大学ꎬ２００７.[２１]㊀ＬｉｕＢꎬＬａｎｇｅＦＦ.Ｐｒｅｓｓｕｒｅｉｎｄｕｃｅｄｔｒａｎｓｉｔｉｏｎｂｅｔｗｅｅｎｓｕｐｅｒｈｙｄｒｏｐｈｏｂｉｃｓｔａｔｅｓ:ｃｏｎｆｉｇｕｒａｔｉｏｎｄｉａｇｒａｍｓａｎｄｅｆｆｅｃｔｏｆｓｕｒｆａｃｅｆｅａｔｕｒｅｓｉｚｅ[Ｊ].ＪｏｕｒｎａｌｏｆＣｏｌｌｏｉｄ＆ＩｎｔｅｒｆａｃｅＳｃｉｅｎｃｅꎬ２００６ꎬ２９８(２):８９９￣９０９.[２２]㊀ＫａｌｉｎＭꎬＰｏｌａｊｎａｒＭ.Ｔｈｅｅｆｆｅｃｔｏｆｗｅｔｔｉｎｇａｎｄｓｕｒｆａｃｅｅｎｅｒｇｙｏｎｔｈｅｆｒｉｃｔｉｏｎａｎｄｓｌｉｐｉｎｏｉｌ￣ｌｕｂｒｉｃａｔｅｄｃｏｎｔａｃｔｓ[Ｊ].ＴｒｉｂｏｌｏｇｙＬｅｔｔｅｒｓꎬ２０１３ꎬ５２(２):１８５￣１９４.[２３]㊀叶㊀伟.强流脉冲电子束处理对热模压脱模性能的影响[Ｄ].重庆:重庆理工大学ꎬ２０１３.[２４]㊀ＷａｎｇＣꎬＫｕｚｕｕＮꎬＴａｍａｉＹ.Ｍｏｌｅｃｕｌａｒｄｙｎａｍｉｃｓｓｔｕｄｙｏｎｓｕｒｆａｃｅｓｔｒｕｃｔｕｒｅｏｆｈｏｔｗｏｒｋｉｎｇｔｅｃｈｎｏｌｏｇｙα￣ＳｉＯ２ｂｙｃｈａｒｇｅｅｑｕｉｌｉｂｒａｔｉｏｎｍｅｔｈｏｄ[Ｊ].ＪｏｕｒｎａｌｏｆＮｏｎ￣ＣｒｙｓｔａｌｌｉｎｅＳｏｌｉｄｓꎬ２００３ꎬ３１８:１３１￣１４１.。
材料科学与工程专业英语匡少平课后翻译答案精编WORD版
材料科学与工程专业英语匡少平课后翻译答案精编W O R D版IBM system office room 【A0816H-A0912AAAHH-GX8Q8-GNTHHJ8】Alloy合金applied force作用力amorphous materials不定形材料artificial materials人工材料biomaterials生物材料biological synthesis生物合成biocompatibility生物相容性brittle failure脆性破坏carbon nanotub e碳纳米管carboxylic acid羟酸critical stress临近应力dielectric constant介电常数clay minera l粘土矿物cross-sectional area横截面积critical shear stress临界剪切应力critical length临界长度curing agent固化剂dynamic or cyclic loading动态循环负载linear coefficient of themal expansio n性膨胀系数electromagnetic radiation电磁辐射electrodeposition电极沉积nonlocalizedelectrons游离电子electron beam lithography电子束光刻elasticity 弹性系数electrostation adsorption静电吸附elastic modulus弹性模量elastic deformation弹性形变elastomer弹性体engineering strain工程应变crystallization 结晶fiber-optic光纤维Ethylene oxide环氧乙烷fabrication process制造过程glass fiber玻璃纤维glass transition temperature 玻璃化转变温度heat capacity热熔Hearing aids助听器integrated circuit集成电路Interdisplinary交叉学科intimate contact密切接触inert substance惰性材料implant移植individual application个体应用deformation局部形变mechanical strength机械强度mechanical attrition机械磨损Mechanical properties力学性Materials processing材料加工质mechanical behavior力学行为magnetic permeability磁导率magnetic hybrid technique混合技术induction磁感应mass per unit of volume单位体积质量monomer identity单体种类molecular mass分子量microsphere encapsulation technique微球胶囊技术macroscopical宏观的naked eye 肉眼nonlocalized nanoengineered materials纳米材料nanostructured materials纳米结构材料nonferrous metal有色金属线nucleic acid核酸nanoscale纳米尺度Nanotechnology纳米技术nanobiotechnology纳米生物技术nanocontact printing纳米接触印刷optical property光学性质optoelectronic device光电设备oxidation degradation 氧化降解piezoelectric ceramics压电陶瓷Relative density相对密度stiffnesses刚度sensor传感材料semiconductors半导体specific gravity比重shear 剪切Surface tention表面张力self-organization自组装static loading静载荷stress area应力面积stress-strain curves应力应变曲线sphere radius球半径submicron technique亚微米技术substrate衬底supramolecalar超分子sol-gel method溶胶凝胶法thermal/electrical conductivity 热/点导率thermoplastic materials热塑性材料Thermosetting plastic热固性塑料thermal motion热运动toughness test韧性试验tension张力torsion扭曲Tensile Properties拉伸性能Two-dimentional nanostructure二维纳米结构Tissue engineering组织工程transplantation of organs器官移植the service life使用寿命the longitudinal direction纵向the initial length of the materials初始长度the acceleration gravity重力加速度the normal vertical axis垂直轴the surface to volume ratio 比表面密度the burgers vector伯格丝矢量the mechanics and dynamics of tissues 组织力学和动力学phase transformation temperature相转变温度plastic deformation塑性形变Pottery陶瓷persistence length余晖长度polymer synthesis聚合物合成Polar monomer记性单体polyelectrolyte高分子电解质pinning point钉扎点plasma etching 等离子腐蚀pharmacological acceptability药理接受性pyrolysis高温分解ultrasonic treatment超射波处理yield strength屈服强度vulcanization硫化1-1:直到最近，科学家才终于了解材料的结构要素与其特性之间的关系。
美国ASHTTO规范
LRFDUS-4-E3
7/30/2007
AASHTO LRFD Bridge Design Specifications
Customary U.S. Units 4th Edition 2007
American Association of State Highway a n d Tr a n s p o r t a t i o n O f f i c i a l s
7/30/2007
Section 8: Wood Structures pp. 8-13–8-34 Article 8.4.1.2.3 Article 8.4.1.3 Article 8.4.4.4 Article 8.4.4.4 Article 8.5.2.4.3 Insert Tables 8.4.1.2.3-1 and 8.4.1.2.3-2 In the title for Table 8.4.1.3-1, change “Base Resistance and Modulus of Elasticity” to “Reference Design Values” Relocate Tables 8.4.4.4-1 and Table 8.4.4.4-2 to the end of Article 8.4.4.4 Delete Table 8.4.4.4-1, Deck Factors, Cp, for Mechanically Laminated Solid Sawn Lumber Decks Change article header “8.5.2.4.3 Stability” to “8.5.2.3 Stability” Section 11: Abutments, Piers, and Walls pp. 11-3/11-4 Article 11.3.1 Article 11.3.1 Article 11.3.1 Article 11.3.1 pp. 11-9/11-10 pp. 11-13/11-14 pp. 11-15/11-16 pp. 11-19/11-20 pp. 11-31/11-32 pp. 11-79/11-80 Article 11.5.6 Article 11.6.2.1 Article 11.6.3.1 Article 11.6.4 Article 11.9.4.3 Article C11.10.11 For PH, change “(11.10.11.1)” to “(11.10.10.1)” For Pv, change “(11.10.11.1)” to “(11.10.10.1)” For P′v, change “(11.10.11.1)” to “(11.10.10.1)” For ΔsH, change “(11.10.11.2)” to “(11.10.10.2)” In paragraphs 1 and 2, change “Tables 10.5.5-1 through 10.5.5-3” to “Tables 10.5.5.2.2-1, 10.5.5.2.3-1, 10.5.5.2.4-1,” Change “Articles 10.6.2.2.3, 10.7.2.3, 10.2.2.3,” to “Articles 10.6.2.4, 106.2.5, 10.7.2.3 through 10.7.2.5, 10.8.2.2 through 10.8.2.4,” Change “Article 10.6.2.2.4” to “Article 10.6.2.5” Change “Article 10.6.3.1.5” to “Article 10.6.1.3” Change “Articles 11.6.3.6, 11.6.3.7,” to “Articles 11.6.3.5, 11.6.3.6,” In paragraph 2, change “Article C10.6.2.2” to “Article C10.5.2.2” Section 12: Buried Structures and Tunnel Liners pp. 12-1/12-2 pp. 12-5/12-6 pp. 12-79/12-80 pp. 12-83/12-84 Article 12.3 Article 12.3 Article 12.3 Article 12.3 Article 12.13.3.3 Article 12.14.5.8 For Bd, change “Article 12.10.2.1.2” to “Article 12.11.2.2” For Cd, change “Article 12.10.2.1.2” to “Article 12.11.2.2” For γs, change “Article 12.9.2.2” to “Article C12.9.2” For μ′, change “μ′ ” to “μ” [no prime] and “(12.10.2.1.2)” to “(12.10.2.1)” Change “Article 12.3.2.2” to “Article 12.13.2.2” Change “Article 5.10.8.2” to “Article 5.10.8” Section 14: Joints and Bearings pp. 14-27/14-28 pp. 14-41/14-42 Article 14.5.6.9.7a Article 14.7.1.2 In paragraph 1, change “Article 6.10.7.4.2” to “Article 6.10.10.2” Change “Table 6.4.1-2” to “Table 6.4.2-1”
结构力学专业英语
结构力学结构力学structural mechanics 结构分析structural analysis 结构动力学structural dynamics 拱Arch 三铰拱three-hinged arch 抛物线拱parabolic arch 圆拱circular arch 穹顶Dome 空间结构space structure 空间桁架space truss 雪载[荷] snow load 风载[荷] wind load 土压力earth pressure 地震载荷earthquake loading 弹簧支座spring support 支座位移support displacement 支座沉降support settlement 超静定次数degree of indeterminacy 机动分析kinematic analysis 结点法method of joints 截面法method of sections 结点力joint forces 共轭位移conjugate displacement 影响线influence line 三弯矩方程three-moment equation 单位虚力unit virtual force 刚度系数stiffness coefficient 柔度系数flexibility coefficient 力矩分配moment distribution 力矩分配法moment distribution method 力矩再分配moment redistribution 分配系数distribution factor 矩阵位移法matri displacement method 单元刚度矩阵element stiffness matrix 单元应变矩阵element strain matrix 总体坐标global coordinates 贝蒂定理Betti theorem 高斯--若尔当消去法Gauss-Jordan elimination Method 屈曲模态buckling mode 复合材料力学mechanics of composites 复合材料composite material 纤维复合材料fibrous composite 单向复合材料unidirectional composite 泡沫复合材料foamed composite 颗粒复合材料particulate composite 层板Laminate 夹层板sandwich panel 正交层板cross-ply laminate 斜交层板angle-ply laminate 层片Ply 多胞固体cellular solid 膨胀Expansion 压实Debulk 劣化Degradation 脱层Delamination 脱粘Debond 纤维应力fiber stress 层应力ply stress 层应变ply strain 层间应力interlaminar stress 比强度specific strength 强度折减系数strength reduction factor 强度应力比strength -stress ratio 横向剪切模量transverse shear modulus 横观各向同性transverse isotropy 正交各向异Orthotropy 剪滞分析shear lag analysis 短纤维chopped fiber 长纤维continuous fiber 纤维方向fiber direction 纤维断裂fiber break 纤维拔脱fiber pull-out 纤维增强fiber reinforcement 致密化Densification 最小重量设计optimum weight design 网格分析法netting analysis 混合律rule of mixture 失效准则failure criterion 蔡--吴失效准则Tsai-W u failure criterion 达格代尔模型Dugdale model 断裂力学fracture mechanics 概率断裂力学probabilistic fracture Mechanics 格里菲思理论Griffith theory 线弹性断裂力学linear elastic fracture mechanics, LEFM 弹塑性断裂力学elastic-plastic fracture mecha-nics, EPFM 断裂Fracture 脆性断裂brittle fracture 解理断裂cleavage fracture 蠕变断裂creep fracture 延性断裂ductile fracture 晶间断裂inter-granular fracture 准解理断裂quasi-cleavage fracture 穿晶断裂trans-granular fracture 裂纹Crack 裂缝Flaw 缺陷Defect 割缝Slit 微裂纹Microcrack 折裂Kink 椭圆裂纹elliptical crack 深埋裂纹embedded crack [钱]币状裂纹penny-shape crack 预制裂纹Precrack 短裂纹short crack 表面裂纹surface crack 裂纹钝化crack blunting 裂纹分叉crack branching 裂纹闭合crack closure 裂纹前缘crack front 裂纹嘴crack mouth 裂纹张开角crack opening angle,COA 裂纹张开位移crack opening displacement, COD 裂纹阻力crack resistance 裂纹面crack surface 裂纹尖端crack tip 裂尖张角crack tip opening angle, CTOA 裂尖张开位移crack tip opening displacement, CTOD 裂尖奇异场crack tip singularity Field 裂纹扩展速率crack growth rate 稳定裂纹扩展stable crack growth 定常裂纹扩展steady crack growth 亚临界裂纹扩展subcritical crack growth 裂纹[扩展]减速crack retardation 止裂crack arrest 止裂韧度arrest toughness 断裂类型fracture mode 滑开型sliding mode 张开型opening mode 撕开型tearing mode 复合型mixed mode 撕裂Tearing 撕裂模量tearing modulus 断裂准则fracture criterion J积分J-integral J阻力曲线J-resistance curve 断裂韧度fracture toughness 应力强度因子stress intensity factor HRR场Hutchinson-Rice-Rosengren Field 守恒积分conservation integral 有效应力张量effective stress tensor 应变能密度strain energy density 能量释放率energy release rate 内聚区cohesive zone 塑性区plastic zone 张拉区stretched zone 热影响区heat affected zone, HAZ 延脆转变温度brittle-ductile transition temperature 剪切带shear band 剪切唇shear lip 无损检测non-destructive inspection 双边缺口试件double edge notched specimen, DEN specimen 单边缺口试件single edge notched specimen, SEN specimen 三点弯曲试件three point bending specimen, TPB specimen 中心裂纹拉伸试件center cracked tension specimen, CCT specimen 中心裂纹板试件center cracked panel specimen, CCP specimen 紧凑拉伸试件compact tension specimen, CT specimen 大范围屈服large scale yielding 小范围攻屈服small scale yielding 韦布尔分布Weibull distribution 帕里斯公式paris formula 空穴化Cavitation 应力腐蚀stress corrosion 概率风险判定probabilistic risk assessment, PRA 损伤力学damage mechanics 损伤Damage 连续介质损伤力学continuum damage mechanics 细观损伤力学microscopic damage mechanics 累积损伤accumulated damage 脆性损伤brittle damage 延性损伤ductile damage 宏观损伤macroscopic damage 细观损伤microscopic damage 微观损伤microscopic damage 损伤准则damage criterion 损伤演化方程damage evolution equation 损伤软化damage softening 损伤强化damage strengthening 损伤张量damage tensor 损伤阈值damage threshold 损伤变量damage variable 损伤矢量damage vector 损伤区damage zone 疲劳Fatigue 低周疲劳low cycle fatigue 应力疲劳stress fatigue 随机疲劳random fatigue 蠕变疲劳creep fatigue 腐蚀疲劳corrosion fatigue 疲劳损伤fatigue damage 疲劳失效fatigue failure 疲劳断裂fatigue fracture 疲劳裂纹fatigue crack 疲劳寿命fatigue life 疲劳破坏fatigue rupture 疲劳强度fatigue strength 疲劳辉纹fatigue striations 疲劳阈值fatigue threshold 交变载荷alternating load 交变应力alternating stress 应力幅值stress amplitude 应变疲劳strain fatigue 应力循环stress cycle 应力比stress ratio 安全寿命safe life 过载效应overloading effect 循环硬化cyclic hardening 循环软化cyclic softening 环境效应environmental effect 裂纹片crack gage 裂纹扩展crack growth, crack Propagation 裂纹萌生crack initiation 循环比cycle ratio 实验应力分析experimental stress Analysis 工作[应变]片active[strain] gage 基底材料backing material 应力计stress gage 零[点]飘移zero shift, zero drift 应变测量strain measurement 应变计strain gage 应变指示器strain indicator 应变花strain rosette 应变灵敏度strain sensitivity 机械式应变仪mechanical strain gage 直角应变花rectangular rosette 引伸仪Extensometer 应变遥测telemetering of strain 横向灵敏系数transverse gage factor 横向灵敏度transverse sensitivity 焊接式应变计weldable strain gage 平衡电桥balanced bridge 粘贴式应变计bonded strain gage 粘贴箔式应变计bonded foiled gage 粘贴丝式应变计bonded wire gage 桥路平衡bridge balancing 电容应变计capacitance strain gage 补偿片compensation technique 补偿技术compensation technique 基准电桥reference bridge 电阻应变计resistance strain gage 温度自补偿应变计self-temperature compensating gage 半导体应变计semiconductor strain Gage 集流器slip ring 应变放大镜strain amplifier 疲劳寿命计fatigue life gage 电感应变计inductance [strain] gage 光[测]力学Photomechanics 光弹性Photoelasticity 光塑性Photoplasticity 杨氏条纹Young fringe 双折射效应birefrigent effect 等位移线contour of equal Displacement 暗条纹dark fringe 条纹倍增fringe multiplication 干涉条纹interference fringe 等差线Isochromatic 等倾线Isoclinic 等和线isopachic 应力光学定律stress- optic law 主应力迹线Isostatic 亮条纹light fringe 光程差optical path difference 热光弹性photo-thermo -elasticity 光弹性贴片法photoelastic coating Method 光弹性夹片法photoelastic sandwich Method 动态光弹性dynamic photo-elasticity 空间滤波spatial filtering 空间频率spatial frequency 起偏镜Polarizer 反射式光弹性仪reflection polariscope 残余双折射效应residual birefringent Effect 应变条纹值strain fringe value 应变光学灵敏度strain-optic sensitivity 应力冻结效应stress freezing effect 应力条纹值stress fringe value 应力光图stress-optic pattern 暂时双折射效应temporary birefringent Effect 脉冲全息法pulsed holography 透射式光弹性仪transmission polariscope 实时全息干涉法real-time holographic interferometry 网格法grid method 全息光弹性法holo-photoelasticity 全息图Hologram 全息照相Holograph 全息干涉法holographic interferometry 全息云纹法holographic moire technique 全息术Holography 全场分析法whole-field analysis 散斑干涉法speckle interferometry 散斑Speckle 错位散斑干涉法speckle-shearing interferometry, shearography 散斑图Specklegram 白光散斑法white-light speckle method 云纹干涉法moire interferometry [叠栅]云纹moire fringe [叠栅]云纹法moire method 云纹图moire pattern 离面云纹法off-plane moire method 参考栅reference grating 试件栅specimen grating 分析栅analyzer grating 面内云纹法in-plane moire method 脆性涂层法brittle-coating method 条带法strip coating method 坐标变换transformation of Coordinates 计算结构力学computational structural mechanics 加权残量法weighted residual method 有限差分法finite difference method 有限[单]元法finite element method 配点法point collocation 里茨法Ritz method 广义变分原理generalized variational Principle 最小二乘法least square method 胡[海昌]一鹫津原理Hu-Washizu principle 赫林格-赖斯纳原理Hellinger-Reissner Principle 修正变分原理modified variational Principle 约束变分原理constrained variational Principle 混合法mixed method 杂交法hybrid method 边界解法boundary solution method 有限条法finite strip method 半解析法semi-analytical method 协调元conforming element 非协调元non-conforming element 混合元mixed element 杂交元hybrid element 边界元boundary element 强迫边界条件forced boundary condition 自然边界条件natural boundary condition 离散化Discretization 离散系统discrete system 连续问题continuous problem 广义位移generalized displacement 广义载荷generalized load 广义应变generalized strain 广义应力generalized stress 界面变量interface variable 节点node, nodal point [单]元Element 角节点corner node 边节点mid-side node 内节点internal node 无节点变量nodeless variable 杆元bar element 桁架杆元truss element 梁元beam element 二维元two-dimensional element 一维元one-dimensional element 三维元three-dimensional element 轴对称元axisymmetric element 板元plate element 壳元shell element 厚板元thick plate element 三角形元triangular element 四边形元quadrilateral element 四面体元tetrahedral element 曲线元curved element 二次元quadratic element 线性元linear element 三次元cubic element 四次元quartic element 等参[数]元isoparametric element 超参数元super-parametric element 亚参数元sub-parametric element 节点数可变元variable-number-node element 拉格朗日元Lagrange element 拉格朗日族Lagrange family 巧凑边点元serendipity element 巧凑边点族serendipity family 无限元infinite element 单元分析element analysis 单元特性element characteristics 刚度矩阵stiffness matrix 几何矩阵geometric matrix 等效节点力equivalent nodal force 节点位移nodal displacement 节点载荷nodal load 位移矢量displacement vector 载荷矢量load vector 质量矩阵mass matrix 集总质量矩阵lumped mass matrix 相容质量矩阵consistent mass matrix 阻尼矩阵damping matrix 瑞利阻尼Rayleigh damping 刚度矩阵的组集assembly of stiffness Matrices 载荷矢量的组集consistent mass matrix 质量矩阵的组集assembly of mass matrices 单元的组集assembly of elements 局部坐标系local coordinate system 局部坐标local coordinate 面积坐标area coordinates 体积坐标volume coordinates 曲线坐标curvilinear coordinates 静凝聚static condensation 合同变换contragradient transformation 形状函数shape function 试探函数trial function 检验函数test function 权函数weight function 样条函数spline function 代用函数substitute function 降阶积分reduced integration 零能模式zero-energy mode P收敛p-convergence H收敛h-convergence 掺混插值blended interpolation 等参数映射isoparametric mapping 双线性插值bilinear interpolation 小块检验patch test 非协调模式incompatible mode 节点号node number 单元号element number 带宽band width 带状矩阵banded matrix 变带状矩阵profile matrix 带宽最小化minimization of band width 波前法frontal method 子空间迭代法subspace iteration method 行列式搜索法determinant search method 逐步法step-by-step method 纽马克法Newmark 威尔逊法Wilson 拟牛顿法quasi-Newtonmethod 牛顿-拉弗森法Newton-Raphson method 增量法incremental method 初应变initial strain 初应力initial stress 切线刚度矩阵tangent stiffness matrix 割线刚度矩阵secant stiffness matrix 模态叠加法mode superposition method 平衡迭代equilibrium iteration 子结构Substructure 子结构法substructure technique 超单元super-element 网格生成mesh generation 结构分析程序structural analysis program 前处理pre-processing 后处理post-processing 网格细化mesh refinement 应力光顺stress smoothing 组合结构composite structure。
一种用于FDM型3D打印的改性PBT
一种用于FDM型3D打印的改性PBT曹世晴;孙莉;薛为岚;曾作祥;朱万育【摘要】以对苯二甲酸(PTA)、间苯二甲酸(PIA)、癸二酸(SA)和1,4-丁二醇(BDO)为原料,通过直接酯化和减压缩聚的方法制备了一种适合熔融沉积打印(FDM)型3D 打印的改性聚对苯二甲酸丁二醇酯(PBT)——聚对苯二甲酸间苯二甲酸癸二酸丁二醇酯(PBTIS).采用核磁共振氢谱(1 H-NMR)、凝胶渗透色谱法(GPC)、差示扫描量热法(DSC)、黏度计和熔体仪、万能电子拉力机和冲击试验机分别研究了其热性能、流变性能和力学性能.研究表明:当n(PTA)∶n(PIA)=7∶3,SA的物质的量分数为3％～5％时,PBTIS具有合适的熔点、良好的拉伸强度和弯曲强度及悬梁缺口冲击强度等力学性能.用桌面拉丝挤出机将PBTIS样品制成卷材并用3D打印机打印,结果表明其可以流畅地打印出所设计的三维物件.【期刊名称】《功能高分子学报》【年(卷),期】2016(029)001【总页数】5页(P75-79)【关键词】改性PBT;3D打印;力学性能;间苯二甲酸;癸二酸【作者】曹世晴;孙莉;薛为岚;曾作祥;朱万育【作者单位】华东理工大学化工学院,上海200237;华东理工大学化工学院,上海200237;华东理工大学化工学院,上海200237;华东理工大学化工学院,上海200237;上海天洋热熔胶有限公司,上海201802【正文语种】中文【中图分类】TQ3253D打印技术作为第三次工业革命的代表性技术之一［1］,是一种基于三维CAD模型数据并通过材料逐层沉积的方式形成目标物体的技术。
它可以简化产品的制造程序,缩短产品的研制周期,打印形状独特、结构复杂的几何体［2］。
熔融沉积打印（FDM）是一种最常用的3D打印技术,它采用热融喷头,使塑性材料经熔化后从喷头内挤压而出,并沉积在指定位置后固化成型［3］。
用于FDM型3D打印的材料必须是热塑性的［4］,比如PLA［5］、ABS［6］、PCL［7］等复合材料［8］。
PLA材料在FDM过程中翘曲变形的优化
主題：曙材制造Additive Manufacturing2019年第8期PLA材料在FDM过程中翘曲变形的优化**国家自然科学基金资助项目（51775325）魏士皓屠晓伟任彬杨庆华（上海大学机电工程与自动化学院，上海200072）摘要:翘曲变形是熔融沉积成型（FDM）过程中经常出现的问题。
影响精度变化的主要因素是打印喷头温度、打印速度以及成型室温度。
基于有限元仿真软件ANSYS,采用生死单元技术，对3D打印过程中的不同参数进行了对比模拟，得到了最优的打印参数为：打印喷头温度为200七，打印速度为30rnin/s,成型室温度为35迟。
对以后的3D打印提供了参数选择依据。
关键词:FDM；PLA；ANSYS;数值模拟;翘曲变形中图分类号:TH164文献标识码:ADOI：10.19287/ki.1005-2402.2019.08.004The optimization of PLA material warping deformation in FDM processWEI Shihao,TU Xiaowei,REN Bin,YANG Qinghua(School of Mechatronic Engineering and Automation,Shanghai University,Shanghai200072,CHN)Abstract:Warping deformation is a common problem in the process of fused deposition molding(FDM).The main factors influencing the accuracy change are the temperature of the nozzle,the speed of printing and the temperature of the forming environment.Based on the finite element simulation software ANSYS,by a-dopting the technology of cell life and death,the different parameters in the process of3D printing are compared and simulated.The optimal printing parameters:print nozzle temperature is200°C,the printing speed is30mm/s,molding environment sitting temperature of35弋，which provides the parameter selection basis for the future3D printing.Keywords:FDM；PLA；ANSYS；numerical simulation；buckling deformation熔融沉积成型（fused deposition modeling,FDM）技术是近几十年快速发展起来的快速成型技术。