镁合金资料文献
第十章 镁合金
第十章镁合金1.1 引言镁合金从19 世纪初应用到现在，已有近200 年的历史。
主要用于制备铝合金、钢铁脱硫等，作为工程结构材料使用较少，主要应用于航空、航天领域。
随着社会的快速发展，金属材料的消耗日益增多，对铁、铝、铜等金属的需求持续增长，常用的金属资源已经表现出逐年短缺的势态，而镁是世界上最丰富的矿产资源之一，其在地壳中的储量极其丰富，约占地壳总储藏量的2.77%，居第8位。
在大多数国家都能发现镁矿石，但最主要的资源还是海水，海水中含有丰富的镁，含量为0.13%，也就是说每立方米海水中约含有0.13 kg镁，因而海水为人们提供了取之不尽的镁资源。
从20 世纪80 年代后开始，镁合金在工程领域的广泛应用越来越受到重视，更是在90 年代之后得到突飞猛进的发展。
近10 年来，全世界的镁产量翻了一倍，世界各国纷纷把镁资源作为21 世纪的重要战略资源进行规划。
美、日、欧等发达国家对此均极为重视，并为攻克镁合金在各个生产环节的关键技术进行了大型的综合性研究。
我国具有丰富的镁资源，菱镁矿储量、原镁产能、产量和出口均居世界首位，目前原镁产量约占世界总产量的70%。
但是在镁和镁合金的研究和应用领域，我国与欧美发达国家之间的差距还相当大，一方面，我国的原镁产量高、但质量差，镁合金锭的质量也很不尽人意，大多只能廉价出口，另一方面，镁合金在国内的应用较少，高性能镁合金的开发和应用就更为缺乏。
因此，如何利用我国的镁资源优势，将镁的资源优势转变为技术、经济优势，促进国民经济发展、增强我国在镁行业的国际竞争力，是摆在我们面前的迫切任务。
1.2 镁及镁合金的特点镁(Magnesium, Mg)，位于元素周期表IIA族，原子序数12，属于活泼性碱金属，电子轨道分布1s22s22p63s2。
纯镁具有密度小、化学性质活泼等特点，其常见的物理、化学性质见表1.1。
标准大气压下纯镁的晶体结构为密排六方结构，晶格常数a=0.321nm，c=0.521，c/a=1.623（非常接近密排系数1.633），α=β=90°，γ=120°，镁原子在晶胞中的位置及各主要晶面和晶向如图1.1所示。
镁合金论文
AZ91粉末状镁合金的氢化处理及组织演变摘要镁合金是目前最轻的金属结构材料具有比强度高、比刚度高、耐腐蚀、切削加工性能好、易于回收利用等一系列的优点，因而有着极其重要的应用价值与广阔的应用前景。
但是，现有镁合金常温下的塑性变形能力和塑性加工性能仍然较低，限制了其应用。
因此，提高各类镁合金的强度，改善其塑性，是拓展镁合金应用领域推动镁合金发展的关键。
通过细化晶粒制备纳米晶镁合金，能够提高现有各类镁合金材料的强度和塑性，是发展镁合金的有效途径。
当镁合金粉末经氢化—歧化—脱氢—重组工艺处理后，粉末的微观组织被大幅度细化到纳米级。
进一步研究发现，当粉末经脱氢重组后，其晶粒虽有所长大，但仍可保持在纳米级，这一过程被称为HDDR处理。
本文主要研究粉末状镁合金的氢化过程及温度、氢压对氢化过程的影响。
本研究选择应用广泛的AZ91镁合金。
采用“镁合金氩气中磨制成粉末→氢化处理→真空脱氢→组织性能分析测试”的工艺路线，来研究粉末状镁合金的氢化脱氢过程，对其微观结构，相组成的变化进行研究。
利用X 射线衍射(XRD)和扫描电子显微镜（SEM）对镁中MgH2的体积分数和表面形貌的变化进行分析。
由于实验仪器出了故障，本次试验需先将仪器修理完善。
关键词：AZ91镁合金，HDDR处理，氢化反应，晶粒细化，纳米晶材料HYDROGEN PROCESSING AND MICROSTRUCTURE EVOLUTION OF AZ91 MAGNESIUM ALLOYABSTRACTMagnesium alloys is the lightest metallic structural material. Due to the unique properties, such as high specific strength and rigidity, easy to recycle and so on, they have great potential for structural applications. However, because of the plastic deformability of magnesium alloys is quite poor at room-temperature, which is an intrinsic drawback to limit their applications. So, enhancing the strength and deformability of magnesium alloy is the key to expand their applications and promote the development of magnesium alloy industry. Grain refinement is the effectual way to enhancing the strength and deformability of Mg alloy.When the magnesium alloy material was treated by hydrogenation- disproportionation-dehydrogenation-restructuring process, the microstructure of the material has been substantially refined to the nanoscale. Further studies shows that the material has been treated by dehydrogenation and restructuring process, its grains would grow up, but still remained at the nanoscale, which is called HDDR processing. The paper mainly studies how the surface of block magnesium alloy is hydrogenated and how the temperature and hydrogenpressure effect to the hydrogenation.In this study, AZ91 has been used, which is currently the most popular magnesium alloy. We study the hydrogenation and dehydrogenation process of the block magnesium alloys, its microstructure, phase composition and surface morphology by “magnes ium alloy ingotslices polishing–hydrogenated–vacuum dehydrogenation–organizations perf ormance analysis test” process. The volume fraction of MgH2 in Mg and changes of the surface topography were analyzed using X-ray diffraction and scanning electronmicroscopy analysis, respectively.KEY WORDS: AZ91 magnesium alloy, HDDR processing, hydrogenation, grain refinement, nanocrystalline materials目录第一章绪论 (1)1.1 引言 (1)1.2 镁及镁合金的概述 (1)1.2.1 镁合金的优异性能 (3)1.3 镁合金的发展及应用 (4)1.3.1 镁合金的发展 (4)1.3.2 镁合金在国防、航空航天工业及汽车中的应用 (5)1.4 镁合金材料的分类及研究状况 (6)1.4.1 细晶镁合金的制备工艺及发展现状 (7)1.4.2 强应变塑性变形晶粒细化技术 (8)1.4.3 快速凝固粉末冶金细晶工艺技术 (9)1.4.4 氢化处理细晶强化镁合金工艺技术 (10)1.5 本课题的目的及意义 (11)1.6 本文的研究内容 (12)第二章实验材料、设备及方法 (13)2.1 实验材料 (13)2.2 实验主要设备 (14)2.3 试样的制备 (15)2.4 组织结构分析 (15)2.4.1 射线衍射分析 (16)2.4.2 金相显微镜分析 (16)2.4.3 扫描电镜分析 (17)2.5 实验工艺方法与过程 (17)2.5.1 试验工艺方法的确定 (17)2.5.2 试验操作流程 (18)第三章氢化处理粉末状镁合金的氢化反应机理 (20)3.1 引言 (20)3.2 镁合金的氢化反应机理 (20)3.2.1 氢分子在镁合金表面的解离吸附 (20)3.2.2 氢离子在镁合金内的扩散与反应 (21)3.3 镁合金氢化过程的影响因素 (21)3.3.1 镁合金自身因素对氢化反应的影响 (21)3.3.2 外界因素对氢化反应的影响 (23)3.3.3 AZ91镁合金氢化处理后的组织演变及分析 (23)3.3.4 镁合金氢化处理前后的组织结构 (24)第四章结论 (27)参考文献 (28)致谢 (30)附录一外文文献原文 (32)附录二外文文献翻译 (36)第一章绪论1.1 引言镁是地壳中分布最广的元素之一，占地壳重量的2.77%，为第四个最丰富的金属元素(位于Al、Fe、Ca)之后。
《镁合金教育资料》课件
列举镁合金相关领域的研究论文和专利作为参考。
镁合金的行业标准和技术规范
介绍镁合金制造和应用中的行业标准和技术规范。
镁合金相关的图书和学术专著
推荐镁合金相关的图书和学术专著供进一步阅读。
展望镁合金在未来的发展前景，包 括新材料、新应用和新技术。
五、总结与展望
1 镁合金市场前景分析
2 镁合金的应用前景展望 3 镁合金研究的一些挑
战和亟待解决的问题
分析镁合金市场的发展前景
展望镁合金在各行业中的应
和商业机会。
用前景和潜在需求。
讨论在镁合金研究中可能面
临的挑战和需要解决的问题。
六、参考文献
化学性质
介绍镁合金与其他元素和物质的 反应性和耐蚀性。
机械性能和加工性能
评估镁合金的强度、韧性和可加 工性。
四、镁合金的应用案例与前景展望
汽车和航空航天领域的应用 案例
探索镁合金在汽车和航空航天工业 中的实际应用示例。
生物医学材料领域的应用案 例
介绍镁合金在生物医学材料制备和 植入中的潜在应用。
镁合金的发展趋势和前景展 望
《镁合金教育资料》PPT 课件
这是一份关于镁合金的 PPT 课件。通过本课件，您将了解镁合金的背景介绍、 组成和制造、性能和特点、应用案例与前景展望等内容。
一、背景介绍
镁合金的概念
了解镁合金的定义和基本概念。
镁合金的应用领域
探索镁合金在不同领域中的广泛应用，如汽车、航空航天等。
镁合金的优点
介绍镁合金相对于其他材料的优势和特点。
二、镁合金的组成和制造
1
镁合金的主要组成成分
详细讨论镁合金的主要组成成分和相互比例。
镁合金（AZ60）Ca.doc
镁合金(AZ60)Ca第 1 章镁合金材料涂层的研究进展1.1引言传统的医用可植入材料主要是不锈钢、钛合金和钴-铬合金等[1-5]。
这些生物材料弹性模量大，植入后对周围骨组织产生应力遮挡，阻碍了正常的骨形成及塑形[6-8]；传统的植入材料虽具有很强的抗腐蚀性，但少量腐蚀产生或磨损过程中释放的金属离子具有细胞毒性，易引起局部组织炎性反应，降低了材料的生物相容性[9-11]；此外，这些金属可植入材料一般在骨组织愈合后需要二次手术取出，反复手术增加了患者的病痛和感染几率，同时加重了医疗资源的消耗与社会及个人的经济负担[12,13]。
镁合金材料具有以下特点：1，重量轻，密度低，强度大，弹性模量（约45GPa）相比传统植入材料如钛合金弹性模量103-107GPa，镁合金材料弹性模量与骨组织的弹性模量（18.6-27GPa）更接近。
这一特性可以大大减少传统植入材料植入后引起的应力遮挡问题[14-17]；2，镁合金材料的另一优势是其可降解性。
当镁合金材料植入体内后，如果能够控制其降解速度，使其缓慢降解，这样就可避免因二次手术而可能产生的各种危险和减轻患者及社会的经济负担等问题[18,19]；3，镁是人体必需的元素之一，它是维持细胞生理功能的重要组成部分，与生理健康有着极其密切的联系。
镁作为人体液内重要阳离子，参与调节机体内各种酶的活性，控制神经传导兴奋性，维持DNA 结构的稳定性及调节蛋白质合成、肌肉收缩等功能[20,21]。
镁基质合金可降解特性又是一把双刃剑，由于镁是极其活跃的金属元素，在生理体液内，尤其是含有氯离子的溶液中，极易发生降解反应，降解速度非常快[22]。
如何提高镁基质材料或镁合金材料的抗腐蚀性，减慢镁基质材料的降解速度一直成为镁基质材料快速发展的瓶颈。
2003 年，德国人Heublein[23]利用镁铝合金制得动脉支架模型植入到动物猪的动脉内。
实验结果显示：镁合金材料在一定时间内维持了很好的机械支架作用，且随着血管支架的逐渐降解血管腔的粗细程度并没有明显的缩小改变。
镁合金文献
MAGNESIUMBy Robert E (Bob) BrownMagnesium Monthly ReviewWorld magnesium production in 2004 increased slightly compared with2003. There were further announcements of new, modified, and expanded primary magnesium production plans. Some were old and some quite new. There were also expansions and new secondary (recycling) plants announced.Chinese magnesium producers increased their production and share of the world market for the 11th consecutive year, but ran into some difficulties that increased the price of magnesium in 2004. The price of energy increased, thereby increasing the costs of FeSi, the main reducing agent.Europe is increasing the use of magnesium faster than the US, which continues as the biggest magnesium consumer. Demand in Asia is growing quite rapidly as many neighbouring countries take advantage of Chinese produced magnesium. China has a rapidly growing domestic consumption.Further demand growth will require the use of more Chinese magnesium until the planned electrolytic projects can be built and become operational.Magnesium productionWorld production of primary magnesium metal increased slightly over the previous year. The major portion of the increase again came from China, which produced a record 438,000 t, up 19% from 2003.Table 1. World magnesium productionCOUNTRY 1995 199619971998 1999 2002001200220032004UnitedStates(1)142 143 140 117 85 74 43 35 43 43 Brazil (1) 10 11 9 9 7 9 9 7 6 11 Canada (2) 42 52 54 57 54 55 65 86 50 55 PR ofChina(100e)60 56 92 120 157 195 195 232 354 438 France 10 11 161517 17 7 0 0 0 Israel (1) -- -- 725 25 2 30 34 30 33 Kazakhstan (1) 12(r) 12(r 15(r) 15(r) 15 10 10 10 14 14e Norway 35 38 52 49 52 50 35 10 0 0 Russia (2) 51r 51r 51r 53 r 56 40 50 52 45 45 Ukraine 8r13 r 7 r 6 r 6e 2 2 0 0 0 Serbia (1) 1 2 3 3 1e 2 2 2 2 4e India 1 1 1 1.5 1 0.5 0.5 0 0 0 Total 372 390 447 470.5 476 479.448.468 544 6435 5Source: USGS, IMA, CMA, Author estimatese = estimate, r = revision, ( ) = number of operating plants in the countryUnited StatesPrimary magnesium production in the US was estimated as 43,000 t. The only remaining US magnesium producer continues to be US Magnesium Llc(formerly MagCorp).US Magnesium operated its plant at the Great Salt Lake, near Salt Lake City, Utah, with the same management and workforce. The 30 new electrolytic cells and plant modifications are nearly four years old. Cell-life estimates for the new cells have been nearly doubled.US Magnesium Llc announced in September 2004 that it would initiate a further expansion of its magnesium production capabilities. The nameplate capacity of the facility will be increased to 51,000 t/y, utilising the highly efficient electrolytic technology developed by US Magnesium that has proven to reduce energy and labor unit costs significantly. New metal production will be available in July 2005. The expansion will also increase the amount of by-product chemicals such as chlorine, that the company will have available to market. Further expansion to 59,000 t/y and eventually to 73,000 t/y is being studied.It was also noted in a Salt Lake newspaper that “word of US Magnesium increasing production once would have caused an outcry among environmentalists. But this project has not incited objections, largely because the new electrolytic technology has drastically reduced chlorine emissions released while extracting magnesium from the Great Salt Lake's brackish waters”. The new cell technology also cuts energy demand by 25%.Advanced Magnesium Alloy Corp (Amacor), the company that bought the former Xstrata Magnesium recycling plant in Anderson, Indiana, continued to operate its specially designed 25,000 t/y magnesium scrap melting operation through 2004. The plant was hit with a fire on January 14, 2005, and the scrap receiving warehouse area was severely damaged. The special magnesium recycling equipment also suffered some damage. The plant will be rebuilt, repaired and put back into operation.In Alabama, Remag’s idled recycling plant was hit by Hurricane Ivan in September 2004 and was completely destroyed. MagReTech, the newer plant developed by Garfield Alloys, continued to recycle Class 1 magnesium die-casting scrap. Halaco, the recycling plant in California, which had declared bankruptcy, was closed and was due to be liquidated at the end of the year.A new secondary magnesium plant is being installed in a vacant foundry in Camden, Tennessee. MagPro, a Tennessee-chartered company, will be the owner and operator. The foundry was previously owned by Citation Corp., which produced castings and assembled components for the automobile industry. MagPro is owned by John Haack and family. The Haack family, which previouslyran Halaco, has been in the secondary magnesium business for many years, and has developed an innovative magnesium recovery technology that can efficiently and safely recycle magnesium dross, skimming, and Class 1 scrap.Nuclear Regulatory Commission staff held a public meeting in July 2004, in Bay City, Michigan, to discuss the NRC’s clean-up and decommissioning requirements for two nearby sites that have low levels of thorium, a naturally-occurring radioactive material. The sites, located at Kawkawlin, contain thorium contamination resulting from the production of a magnesium-thorium metal alloy by a company that has gone out of business.Thorium-contaminated waste material at the two sites is encapsulated, with a clay cover and walls to prevent the movement of groundwater through the wastes. Other hazardous chemical wastes are also present at the sites but there are no immediate radiological hazards. (Magnesium-thorium alloys were used in castings and in rolled sheet during the 1950-60s and much of the rolled sheet that was used in rocket construction was magnesium-thorium. It was melted and cast as just another alloy in magnesium sand foundries. Those employees who worked with the melting and casting wore film badges to check the amount of exposure. The radiation was quite small.)Bioconvergence, Inc.continues to operate a magnesium alloy turnings recycling plant in Niagara Falls, NY, and is continuing to look at melting the scrap and pouring magnesium ingots.CanadaGossan Resources Ltd has entered into an agreement with Hatch Engineering of Montreal for the first in a series of studies that, collectively, would embody a preliminary feasibility study for its Inwood magnesium project. Currently, an initial economic assessment utilizing Mintek of South Africa's new atmospheric silicothermic magnesium extraction process is under way. The Manitoba Government's Trade and Investment office is providing some assistance to the project.Mintek is developing an advanced thermal magnesium extraction process based on silicothermic reduction of calcined dolomite. The technology is potentially superior to both the Pidgeon and the Magnetherm conventional vacuum processes as it operates at atmospheric pressure and at slightly higher temperatures for better recoveries and throughputs. This new continuous process technology will likely provide for substantially larger production units than the Magnetherm process, with expected improvements to capital and operating costs. Manitoba Hydro's low-cost industrial electricity rates could also provide this energy-intensive project with a significant cost advantage.Timminco Ltd decided to delay the announced four-month closure of its magnesium furnaces at Haley, Ontario. This decision was made because of anunanticipated increase in customer demand for its ultra high-purity magnesium. The closure, originally planned for August through November 2004, is still being deferred.Timminco was exempted from antidumping duties during the original findings of the US Commerce Department many years ago. Timminco produces magnesium using the Pidgeon silicothermic reduction process (small batch type of horizontal retorts.) This is the same process predominantly used in China. Its Haley plant has great historic significance in that it was the site of the first silicothermic magnesium production plant built under the direction of Dr Lloyd M Pidgeon, the man who developed the commercial silicothermic process.Leader Mining International Inc’s management has reported continuing progress on the Cogburn magnesium project in southwestern British Columbia. Activities are now being conducted under North Pacific Alloys Ltd, a BC-registered corporation and a wholly owned subsidiary of Leader Mining. The company continues to work to develop a US$1.24 billion integrated magnesium quarry and smelter operation. Plant size in the original feasibility study by Hatch Engineering was 131,000 t/y of magnesium and magnesium alloys.Nichromet Extraction Inc signed an agreement with LAB Chrysotile concerning the construction of an industrial pilot plant that will extract nickel and magnesium compounds from chrysotile tailings located in Thetford Mines, Quebec. The past production of chrysotile in Quebec has resulted in producing tailings containing approximately 0.25% Ni and 37-40% MgO. The tailings project is a JV between Nichromet and LAB, and there are an estimated 750 Mt containing nickel worth US$10 billion at current prices.Nichromet is a private Montreal-based company and has been testing hydrometallurgical processes over the past five years. These are targeted towards the extraction of mineral that is refractory to conventional processes. Nichromet has developed technology that is patent pending in Canada and many other countries. This technology allows for the simultaneous extraction of nickel and various magnesium compounds (chloride oxide). According to the agreement between LAB and Nichromet, Nichromet will be responsible for financing the cost of the pilot plant to be located within the LAB premises in Thetford Mines. Nichromet will also be responsible for financing a full feasibility study on the project to be concluded within the next 24 months. The Nichromet technology is a hydrometallurgical process based on chloridation. The operation is conducted at a low temperature with the recycling of water. The solid rejects are inert and insoluble. In these conditions the process respects government norms with regards to the environment.Norsk Hydro is the largest primary magnesium metal producer in Canada, using magnesite imported from China and Australia to produce approximately 43,000 t/y of primary magnesium by a special electrolytic process at Becancour,Quebec. The plant also operates a 10,000 t/y recycling facility. Hydro plans to upgrade the magnesium plant. Production will increase by 7,000 t/y to 58,000 t/y of cast primary metal.Work to expand the plant will start in early 2005 and will take 1½ years to complete. The programme will consist principally of improvements in the dehydration section of the plant and the addition of four electrolytic cells. The plant had been incrementally upgraded from its original 43,000 t/y capacity by debottlenecking and other process improvements.Noranda has no plans to restart its idled Magnola primary magnesium plant in Quebec, despite higher magnesium prices and the US Commerce Dept revoking the antidumping duty order on pure magnesium from Canada, retroactive to August 1, 2000, the effective date of the original full sunset review. The rate had applied to Magnola since it started production in 1999. Magnola ceased production in 2003 after reaching only 60% of its 58,000 t/y capacity because of weak market conditions. Noranda said the revocation is a secondary consideration. The plant was shut down temporarily two years ago and will remain shut down. Noranda's primary focus is on market conditions, such as supply and demand and the Canadian dollar versus the US dollar. Recent currency appreciation hurt as revenues are in US dollars. Noranda had discussions near the end of 2004 with Minmetals Group from China, which is interested in purchasing the total corporation. No specific reference was made at that time to the magnesium operations.Magnesium Alloy Corp of Halifax, Nova Scotia. announced that MagEnergy Inc, a wholly owned energy subsidiary, has signed a preliminary agreement with Soc Nationale d'Electricite (SNEL), the owner and manager of the Inga hydroelectric facility in the Democratic Republic of the Congo. MagEnergy's principal endeavour is to allocate part of the electricity generated by the dam to MagAlloy's Kouilou magnesium project located 200 km west of Inga at the deepwater port city of Pointe-Noire in the Republic of the Congo. SNEL’s management committee and board of directors have approved the agreement. MagEnergy -- together with Rusal, SNC-Lavalin, Eskom, IDC and others – is negotiating with SNEL and the Minister of Mines and Energy, and hopes shortly to conclude this comprehensive agreement for the rehabilitation of all the turbines currently installed at Inga 1 and 2. Besides supplying electricity to MagAlloy's Kouilou plant, electricity sales are also being considered to supply demand in Cabinda (Angola), the Republic of Congo and other neighbouring countries.The Inga hydroelectric site currently consists of the Inga 1 station, which consists of six turbines totalling 351 MW, and the Inga 2 station that consists of eight turbines totalling 1,402 MW. The Inga stations have been highlyunderused since their construction more than 20 years ago. The Inga site, located on the Congo River, represents one of the largest hydroelectric sites in the world that can be expanded at a low cost and without any significant environmental impact.MagEnergy entered into an agreement whereby a consortium called the CTEI (Consortium pour le Transport d'Energy d'Inga) was established. The CTEI targets the construction of a new electrical transmission line to connect Inga with MagAlloy's Kouilou magnesium plant site at Pointe-Noire.Spectra Premium Industries Inc (SPI) has signed an agreement in principle to proceed with the acquisition of 90% of Trimag, a limited partnership headquartered in Boisbriand, Quebec. Investissement Quebec will own the other 10% in Trimag, which is one of the most important North American manufacturers of high-pressure die-cast magnesium alloy parts used in the automotive industry. Created in 1995, Trimag was acquired in 2001 by Soc de Developpement du Magnesium, a limited partnership held by three institutional investors, namely Soc Generale de Financement, Sofinov, a subsidiary of Caisse de Depot et Placement du Quebec, and Solidarity Fund QFL.Trimag has two plants, one in Boisbriand, which began operations in 2002, and the other in Haley, Ontario. At present, nearly all of Trimag's revenues are generated as a Tier 2 supplier in reference to vehicles manufactured by General Motors.The new Boisbriand plant is equipped with two 3,500-t presses, which makes Trimag one of the few companies in North America having the infrastructure to produce large magnesium parts, such as instrument panel beams. The plant will operate at full capacity as of the summer of 2005, as a new supply contract for instrument panel beams for a General Motors plant located in China will have entered into production. Trimag anticipates investing between C$10-million to C$15 million for the expansion and for the acquisition of new equipment.United KingdomMagnesium Elektron, a division of Luxfer, has continued to produce secondary magnesium at its plant in the Manchester area.Birmingham-based Advanced Powder Technology won the Queen's Award for Enterprise for its new, high-yield process for manufacturing atomised magnesium powder. Over the past three years, APT's turnover has more than doubled to £800,000. The company produces powder used in countermeasures against heat-seeking missiles. Using an innovative process to produce the powder has significantly improved the previously expensive and low-yield system.BrazilBrasmag has continued to run its special process silicothermic plant at Bocaiuva. The plant is estimated to have produced 11,000 t in 2004. The plant uses a special modified silicothermic (Bolzano) process developed by Ravelli. The company has been investigating other technologies but by the end of 2004 no decisions had been made.NorwayNorsk Hydro continues to run the magnesium casting operations at the plant in Porsgrunn, rated at 20,000 t/y. The plant remelts scrap and some imported pure magnesium. Norsk Hydro has expanded its recycling plant at Bottrop in Germany to 15,000 t/y from 7,500 t/y.The NetherlandsAntheus Magnesium has formed a JV with Remag of Austria to build and operate a 10,000 t/y magnesium recycling plant in northern Holland. Scrap is obtained from the various magnesium-casting operations in Europe. The plant is owned 40% by the Northern Netherlands Development Agency (NOM), 40% by Remag Recycling Gmbh and 20% by a private owner. It was reported to be struggling at the end of 2004.IcelandMagnesium production continued to remain on hold. Australian Magnesium Investments holds a 40% stake in the Icelandic Magnesium project.SerbiaBella Sterna operates a Magnetherm process plant and is estimated to have produced 4000 t in 2004.GermanyIMCO Recycling Inc’s German subsidiary VAW-IMCO Guss und Recycling Gmbh started operations at a new 15,000 t/y facility that will melt, refine and cast magnesium ingots from scrap. About 90% of the output of the plant, which is located next to the IMCO Toeging facility, will be provided to the European auto industry. The plant will start at a rate of 5,000 t/y.Norway's Hydro Magnesium has doubled magnesium recycling at Bottrop to 15,000 t/y after opening two new reprocessing lines. The company expanded Bottrop in order to meet growing demand from the domestic and regional automobile sector. The new lines, together with Hydro's Porsgrunn plant in Norway, have made the company the largest recycler of remelt magnesium in Europe, with a total production of 35,000 t/y.IsraelDead Sea Magnesium(DSM), the 65% Israeli-owned company continued to produce magnesium in 2004 and the output was 33,000 t of which half was alloy.Volkswagen of Germany continues to own 35% of DSM. Higher magnesium prices in 2004 enabled the plant to operate at a profit for the first time since starting operation.Czech RepublicMagnesium Elektron Ltd (MEL) is operating a 10,000 t/y magnesium recycling plant northwest of Prague. The plant is toll-melting magnesium scrap for customers across Europe.RussiaSolikamsk Magnesium Works(SMZ) is a large magnesium producer with a 20,000 t/y plant. Solikamsk is Russia's second-biggest magnesium producer and exports almost all of its rare-earth metal products and about 60% of its magnesium and alloys. Silvinit, which owns 56.7% of SMZ, will put close to US$10 million into the construction of two fluidised bed furnaces, with a capacity of 300 t/d of dehydrated carnallite at the SMZ plant. Construction of the furnaces will begin in 2005 and be completed in 2006. SMZ currently takes in 260,000 t/y of enriched carnallite from Silvinit and tolls 10,000 t/y of dehydrated carnallite from Avisma (in the Perm region). The modifications will boost output of magnesium and its alloys from 15,000 to 32,000 t/y to keep up with growing market demand. The new dehydrating furnaces will make it possible to cover SMZ's magnesium electrolysis capacity and produce an additional 40,000-45,000 t/y of dehydrated carnallite.The general designer on the project will be the Galurgia Institute in Perm. The two furnaces are expected to yield benefits of about Rb130 million, according to the feasibility study.Construction of the Asbest magnesium plant, which will produce magnesium from asbestos tailings, is planned to begin at the end of 2005 in the Sverdlovsk region town of Asbest. Representatives of Switzerland's Minmet Financing, one of the founders of the plant, announced the plan at a meeting in Yekaterinburg with Sverdlovsk’s Regional Governor Eduard Rossel on September 30 2004. The main investor in the project is Minmet Financing Co, which holds a controlling interest in the plant, which was set up in April 2004. Anatoly Shchelkonogov, a prominent specialist in magnesium mining and processing who has been named general director of the venture, said that the plant would require about US$300 million of investment to achieve design capacity of 60,000 t/y of magnesium. Mr Shchelkonogov said construction would be split into three stages, with the first producing 20,000 t/y.Avisma’s magnesium operations continued in 2004. The company produced over 30,000 t of magnesium, of which more than 50% was recycled magnesium that is re-used to produce titanium sponge. Avisma is located at Berezniki in the Perm region. It is Russia’s largest producer of magnesium and the world’s largest producer of titanium sponge, with about 30% of the global output.Rusal, Russia’s biggest aluminum producer, will build a plant capable of producing 40,000 t/y of metallic magnesium in the Volgograd region. The company will carry out further exploration at a bischofite field this year and will complete a feasibility study for the magnesium plant. Rusal-Bishofit won a public tender in December 2004 for the right to develop the estimated 50 Mt field in the Gorodnishchensky district of Volgograd region. Rusal will use the magnesium to produce aluminum alloys. Rusal is planning to increase the amount of alloy that it produces by up to 50%. Output of cast-house alloys rose 33.5% to 740,000 t in 2003 and accounted for 27.8% of total aluminium output. Rusal produces more than 80 aluminium alloys.UkraineThe Ukraine has two magnesium plants, Zaporoshe and Kalush. The former has a rated capacity of 40,000 t/y and the latter 10,000 t/y. Both plants were shut down during 2004. However, restoration work was proceeding at the magnesium reduction plant at Kalush, with plans to produce 500 t/mth in early 2005.ONVI is a small company producing magnesium granules from scrap magnesium.KazakhstanThe Ust Kamenogorsk magnesium plant produced an estimated 14,000 t in 2004. The plant in eastern Kazakhstan, produces high-quality titanium sponge and magnesium. Belgium's Specialty Metals owns 66% and ZAO Central Securities Depository 7.3%.South AfricaMintek and its consortium partners, Anglo American plc, power utility Eskom Holdings, and South Africa’s Department of Science and Technology, has been working on the Mintek Thermal Magnesium Project for three years. The objective is to develop a continuous thermal process so as to minimise the number of operators required and to achieve efficiency gains.AustraliaMagnesium International Ltd (MIL) of Australia has confirmed Egypt as the location for a 88,000 t/y magnesium smelter. It will be owned and operated by a special purpose company, Egyptian Magnesium Co (Emag) that is currently being established by MIL and Amiral Investments (MIL’s partner in Egypt, under Egyptian investment laws). The specific site will be inside the new port at Ain Sokhna on the Gulf of Suez Sokhna is a relatively new port but is already the most efficient port in Egypt, with high operating standards. The port operator is Sokhna Port Development Co (SPDC), an affiliate of Amiral. As a port, Sokhna has the ability to handle and rapidly unload large bulk carriers (up to 150,000 dwt) for delivery of magnesite ore, and to ship magnesium in containers worldwide.LaTrobe Magnesium(formerly Rambora Technologies Ltd.) continues to work on a process to produce magnesium metal from ash produced at the LaTrobe Valley power generation plants in Victoria. Latrobe Magnesium decided to ‘change technology ships’, and will abandon plans to use magnesium smelting processes owned by Alcan and replace them with methods developed in Russia. The switch would lower the cost of a bankable feasibility study from US$32 million to US$15.5 million and reduce the time taken for the study from 29 months to 23 months. The process is in use at four magnesium production facilities around the world and eliminates the requirement to construct an expensive pilot-plant facility in Australia. La Trobe would use an existing pilot plant in Russia rather than building one.Sydney-based Quay Magnesium Ltd is building a new 30,000 t/y magnesium alloy plant in China. The plant is being built on the premise that the majority of Chinese primary metal requires further refining and beneficiation to meet high quality European alloy specifications for use in automotive and aeronautical applications. The alloying plant will be built in Nanjing and will produce high quality magnesium alloys. Quay plans to source primary magnesium metal from a number of local Chinese producers, thereby reducing capital costs and technical risks, whilst satisfying a higher end value die-casting market.Quay's plant is relatively simple and features a molten salt refining furnace, rather than the more typical steel crucible furnace, providing for a purer alloy. There is no chemical change involved with the alloying metals and the only physical changes are those associated with the heating and cooling of magnesium metal and its alloys. Quay's primary business will be as a manufacturer and marketer of magnesium alloys, a rapidly growing market. The company plans to produce high-quality European specification alloys that are keenly sought by die-casting companies targeting the automobile and aeronautical industries. .Hella Australia, has designed the Hella HydroLUX FF 1000 Submersible Driving Lamp System to meet the needs of mining, military and emergency services vehicles, as well as rugged off-road sport-utilities and pickup trucks. The new HydroLUX is the only light of its kind on the market to use Hella's Free Form reflector technology, which features a magnesium reflector, the same material used in Formula 1 racing cars and aerospace applications. The durable and fully submersible driving light is built to withstand the most extreme conditions.JapanJapan produced no magnesium in 2004, but had a number of industries producing fabricated parts from magnesium alloys. Kasatani Co has begun mass producing electronic equipment parts using magnesium alloys and recently began shipping parts for personal digital assistants. The new business will make use of existing facilities in Osaka.. It is initially making 10,000 components per month for portable digital assistants, with plans to raise output to 100,000 unitsper month by the end of 2005 to meet anticipated demand for mobile phone and personal computer components. The company targets magnesium alloy parts sales of 300 million yen in the first year. It aims to raise sales in the business to ¥1.2 billion yen in the year ending March 2007.Asahi Tec Corp has begun mass-producing magnesium steering members for supply to Nissan Motor Co. The steering member is part of the instrument panel, which in turn is part of the cockpit module fitted in the car. Steering members made from magnesium are around 40% lighter than those made from iron. Asahi Tec is mass-producing these parts at its Yokochi plant. The plant is making the steering members at a rate of around 5,000 units/mth and shipping them to Calsonic Kansei Corp. where they are used in the assembly of cockpit modules for Nissan's new luxury Fuga.ChinaChina must be given a more definitive treatment since it now produces 68% of the world’s magnesium. The Chinese Magnesium Association (CMA) has developed a reporting system that enables us better to understand the operation of the magnesium industry in China.China's magnesium production reached about 438,000 t in 2004, up 23% from the 354,000 t reported the previous year. China's magnesium exports were also on the rise last year, owing to the increase in output. Output growth in China has been strong. China exported about 383,748 t of magnesium in 2004, up from about 280,000 t reported in 2003. Most exports were to Europe, with a total of about 120,000 t, followed by Asian countries, including Japan and Korea, which accounted for around 65,000 t. Exports to the US from China were down to about 30,000 t in 2004, compared with 42,000 t in 2003. This decrease was due to the large preliminary antidumping duties placed on Chinese magnesium imports. China's domestic consumption reached about 80,000 t in 2004.Table 2: China’s magnesium capacity and production in 20003-04(’000 tonnes)2003 2004 Change% (Y-O-Y) Capacity 600 750 25182 248 36Primary Magnesium IngotoutputMagnesium Alloy 98.8 107 8.3Magnesium Granule (Powder) 68.5 78 13.9Others 4.7 5 6.3Total magnesium output 354 438 23.7Source: Antaike CMA。
材料专业关于镁合金的论文
压铸镁合金压铸镁合金材料的发展历史：1808 年面世, 1886 年始用于工业生产。
镁合金压铸技术[1]从1916 年成功地将镁合金用于压铸件算起，至今也经历了八十余年的发展。
人类在认识和驾驭镁合金及其制品的生产技术方面，经历了漫长的探索历程。
从1927年推出高强度 MgAl9Zn1 开始，镁合金的工业应用获得了实质性的进展。
1936年德国大众汽车公司开始用压铸镁合金生产“甲壳虫”汽车的发动机传动系统零件，1946 年单车使用镁合金量达 18kg 左右。
美国在 1948～1962 年间用热室压铸机生产的汽车用镁合金压铸件达数百万件。
尽管如此，过去镁合金作为结构材料主要用于航空领域，在其它领域，世界上镁的主要用途是生产铝合金，其次用于钢的脱硫和球墨铸铁生产。
近年来, 由于人们对产品轻量化的要求日益迫切，镁合金性能的不断改善及压铸技术的显著进步，压铸镁合金的用量显著增长。
特别是人类对汽车提出了进一步减轻重量、降低燃耗和排放、提高驾驶安全性和舒适性的要求, 镁合金压铸技术正飞速发展。
此外，镁合金压铸件已逐步扩大到其他领域，如手提电脑外壳，手提电锯机壳，鱼钩自动收线匣，录像机壳，移动电话机壳，航空器上的通信设备和雷达机壳，以及一些家用电器具等。
常用的压铸镁合金大多是美国牌号[2]AZ91，AM60，AM50，AM20，AS41 和AE42，分别属于Mg-Al-Zn，Mg-Al-Mn，Mg-Al-Si 和Mg-Al-RE 四大系列。
对压铸镁合金的研究：镁合金的密度小于 2g/cm3，是目前最轻的金属结构材料，其比强度高于铝合金和钢，略低于比强度最高的纤维增强塑料；其比刚度与铝合金和钢相当，远高于纤维增强塑料；其耐腐蚀性比低碳钢好得多，已超过压铸铝合金Ａ380；其减振性、磁屏蔽性远优于铝合金；鉴于镁合金的动力学粘度低，相同流体状态(雷诺指数相等)下的充型速度远大于铝合金，加之镁合金熔点、比热容和相变潜热均比铝合金低，故其熔化耗能少，凝固速度快，镁合金实际压铸周期可比铝合金短50%。
镁合金专业文献6
Elastic constants of binary Mg compounds from first-principles calculationsS.Ganeshan *,S.L.Shang,H.Zhang,Y.Wang,M.Mantina,Z.K.LiuDepartment of Materials Science and Engineering,The Pennsylvania State University,University Park,PA 16802,United Statesa r t i c l e i n f oArticle history:Received 19May 2008Accepted 9November 2008Available online 16December 2008Keywords:B.Elastic propertiesB.Brittleness and ductilityC.ab initio calculationsa b s t r a c tElastic constants (C ij ’s)of 25compounds in the Mg–X (X ¼As,Ba,Ca,Cd,Cu,Ga,Ge,La,Ni,P,Si,Sn,and Y)systems have been predicted by first-principles calculations with the generalized gradient approximation and compared with the available experimental data.Ductility and the type of bonding in these compounds are further analyzed based on their bulk modulus/shear modulus ratios (B /G ),Cauchy pressures (C 12–C 44),and electronic structure calculations.It is found that MgNi 2and MgCu 2have very high elastic moduli.Mg compounds containing Si,Ge,Pb,Sn,and Y,based on their B /G ratios,are inferred as being brittle.A metallic bonding in MgCu 2and a mixture of covalent/ionic bond character in Mg 2Si,as inferred from their electronic structures,further explain the corresponding mechanical properties of these compounds.Ó2008Elsevier Ltd.All rights reserved.1.IntroductionThe applications of magnesium (Mg)alloys in the automobile and aerospace industries have increased significantly over the past years.The ability to predict their deformation behavior will thus be very useful in developing new and tailor existing alloys.Apart from the direct relation between elastic modulus and dispersion strengthening in alloys [1],elastic properties can also be related to other mechanical and physical properties of the material such as ductility and bond characteristics [2–4].Despite their importance,information on the elastic properties of binary Mg compounds is scarce.Among the 25compounds considered in the present study,experimental elastic properties [5–11]were available only for seven of them,i.e.MgCa 2,MgCd 3,MgCu 2,Mg 2Ge,Mg 2Pb,Mg 2Si,and Mg 2Sn.Most of the experimental measurements have been carried out using either the ultrasonic resonance technique or the pulse-echo method.Elastic constants of MgY are available from first-principles calculations in Ref.[12].In the present work elastic constants of Mg compounds in the binary Mg–X systems with X being As,Ba,Ca,Cd,Cu,Ga,Ge,La,Ni,Pb,Sb,Si,Sn and Yare obtained through first-principles calculations using the efficient stress–strain method [13].From the results thus obtained,ductility and bond characteristics of the compounds are analyzed.Electronic structures are also examined for the compounds considered in this study,to rationalize our results.2.Theory and computational detailsHerein,first-principles calculation based on the density functional theory is performed [14].The generalized gradient approximation[15]as incorporated in the Vienna ab initio simulation package [16,17]is employed.The ion–electron interaction is described using the projector augmented wave method (PAW)[18].An energy cut-off of 360eV is used.G point centered k-mesh for hexagonal closed packed structures and Monkhorst–Pack [19]for non-hexagonal structures are incorporated.A k-point mesh of 16,000,8000and 4000k-points per reciprocal atoms is used based on the number of atoms in the primitive unit cell.The k-point mesh mentioned here is generated by the Alloy Theoretical Toolkit (ATAT)code [20].The atomic arrange-ments are relaxed using the Methfessel–Paxton technique [21]for the reciprocal-space integration,following which accurate stresses of the relaxed structures in order to calculate elastic constants are calculatedusing the tetrahedron method with Blo¨chl corrections [22].Elastic constants obtained in the current work are calculated by using the Easy Elastic Constant Calculation (EECC)software devel-oped in our group based on the stress–strain method [13].The methodology used involves applying a set of strains (3¼31,32,33,34,35and 36)with 31–33and 34–36referring to normal and shear strains,respectively.The crystal lattice vectors before (Q )and after ðÞthe strains are applied are related as follows¼Q 0@1þ3136=235=236=21þ3234=235=234=21þ331A (1)In the current study,the following linearly independent set of strains is applied:26666664x 000000x 000000x 000000x 000000x 000000x37777775*Corresponding author.Tel.:D 181********.E-mail address:sxg319@ (S.Ganeshan).Contents lists available at ScienceDirectIntermetallicsjournal homepage:/locate/intermet0966-9795/$–see front matter Ó2008Elsevier Ltd.All rights reserved.doi:10.1016/j.intermet.2008.11.005Intermetallics 17(2009)313–318with x ¼Æ0.01.Based on our previous calculations the strains incor-porated herein are tested to be accurate.A set of stresses (s ¼s 1,s 2,s 3,s 4,s 5and s 6)for the deformed crystals is generated,which is further obtained from first-principles calculations.From the n set of strains (3),and the resulting stresses (s ),elastic stiffnesses (C ij ’s)are then calculated based on Hooke’s law,as shown below.B B B B B B @C 11C 12C 13C 14C 15C 16C 21C 22C 23C 24C 25C 26C 31C 32C 33C 34C 35C 36C 41C 42C 43C 44C 45C 46C 51C 52C 53C 54C 55C 56C 61C 62C 63C 64C 65C 661C C C C C C A ¼0B BB B B B @31;132;133;134;135;136;1.31;n 32;n 33;n 34;n 35;n 36;n1CC CC C C A À10B B B B B B @s 1;1s 2;1s 3;1s 4;1s 5;1s 6;1.s 1;n s 2;n s 3;n s 4;n s 5;n s 6;n1C C C C C C A (2)Voigt’s method is used to calculate the respective bulk (B ),shear (G ),and Young’s (E )moduli as shown below for the highly symmetric structures (orthorhombic and above)[23].B ¼ðC 11þ2C 12Þ=3;(3)G ¼ð11À12þ344Þ=5;(4)E ¼ð9BG Þ=ðG þ3B Þ;(5)where11¼ðC 11þC 22þC 33Þ=3;(6)12¼ðC 12þC 13þC 23Þ=3;(7)C 44¼ðC 44þC 55þC 66Þ=3(8)3.Results and discussionsTable 1lists the lattice parameters calculated as a part of the current work [32]in comparison with the available experimental data and their corresponding crystal structures [24].It can be seen that the difference between the calculated and measured data is lower than 2%.The same is depicted in Fig.1.All the data points lie close to the center line,thus presenting a good agreement between calculated and experimental data.The calculated elastic constants of 25binary Mg compounds together with their available experimental data [5–11]are shown in Table 2.Data has been plotted in Fig.2,only for the independent elastic constants of the cubic compounds (C 11,C 12,C 33,C 44)to explicitly exhibit the agreement between calculated and measured data.The difference in the data for all the compounds shown in Fig.2is less than 10–15%.The elastic constants of MgY,due to unavailable experimental data are compared to those calculated by Wu and Hu [12].The values agree reasonably well.The calculated bulk modulus of the compounds studied herein can be grouped into 4categories as shown in Fig.3.Set I consists of compounds whose bulk moduli are lower than that of pure pounds from the Mg–Ba,Mg–Ca,and Mg–La systems fall under this category.These compounds also fall under Set II which contains compounds whose bulk moduli are larger than those of their corresponding pure elements X.Based on these results it can be expected that elements belonging to group IIA or light rare-earths tend to decrease the elastic properties when alloyed with Mg.Bulk moduli of compounds in set III are between those of pure Mg and their pure elements X.Mg 2Si,Mg 2Sn,Mg 2Ge and Mg 2Pb are contained in this set.MgNi 2,Mg 2Ni and MgCu 2also belong to this category and have considerably large values of bulk modulus when compared to pure Mg.The exceptionally large elastic constants of MgNi 2,Mg 2Ni and MgCu 2compounds can be correlated to their high melting points (797 C for MgCu 2,760 C for Mg 2Ni and 1147 C for MgNi 2)and cohesive energies.Thus,elements fromtheTable 1Calculated and compiled experimental lattice parameters (a ,b ,c )(Å)of MgFig.1.Calculated and experimental lattice parameters (Å)of Mg compounds (Table 1).S.Ganeshan et al./Intermetallics 17(2009)313–318314IVA and transition group can be speculated as those which improve the elastic properties of Mg alloys.Set IV contains compounds which have bulk moduli lower than both pure Mg and their cor-responding pure elements X.In the present study,the compounds are observed to lay primarily within sets I,II and III.To further probe into the mechanical and physical properties of these compounds based on their elastic properties,we analyze their ductility using the (B /G )ratio.The relation between the elastic and plastic properties of pure metals was first proposed by Pugh [3],which was used for compounds later,for e.g.in Ref.[12].According to Pugh [3],metals having a B /G ratio greater than 1.75are ductile whereas metals having a B /G ratio less than 1.75areconsidered brittle.Fig.4plots the B /G ratio of compounds against the B /G ratio of pure elements.As it can be seen in the figure,16of the 25compounds have a B /G ratio greater than 1.75.While pure Mg has a B /G ratio of 2.05,Mg 2Si and Mg 2Ge have the least B /G ratios (1.18).To avoid crowding of the figure,we have only high-lighted compounds with extremities in their B /G ratio.From Fig.4,it can be observed that MgCd 3has a high B /G ratio (3.99),andbasedTable 2B *¼Bulk modulus.G *¼Shear modulus.E *¼Young’smodulus.Fig.2.Calculated and experimental elastic stiffness (GPa)(see Table 2forreference).Fig.3.Bulk modulus (B )of different compounds with respect to their pure elements.The numbers correspond to the name of the compounds as given in Table 1.Set I:compounds with B lower than pure Mg.Set II:compounds B higher than that of pure Mg and the corresponding pure elements.Set III:compounds with B higher than that of pure Mg,but lower than that of their corresponding pure elements.Set IV:compounds with B lower than both pure Mg as well as their corresponding pure elements.S.Ganeshan et al./Intermetallics 17(2009)313–318315on Ref.[3],can therefore be ascribed as being more ductile than brittle.Mg compounds having transition elements like,MgCu 2,Mg 2Ni and MgNi 2also fall in the category where B /G ratio is greater than 1.75and hence can be attributed to having high ductility.Mg–RE (rare-earths)and Mg–IVA compounds,as mentioned earlier,have B /G ratios less than 1.75based on which they can be expected to be brittle.This brittle nature of Mg–IVA compounds has also been reported in the past,e.g.Mabuchi et al.[25]in their work,emphasize the brittle character of Mg 2Si.To obtain a better understanding of the mechanical behavior of the compounds studied in this work,we present a correlation between their binding properties and ductility.In the current study we restrict our correlation to cubic compounds considering the structure to be of primary importance.Bond characteristics of the cubic compounds are explained herein with respect to their Cauchy pressures (C 12–C 44)[4],also see Table 3.This correlation may further be extended to tetragonal,hexagonal (C 12–C 66;C 13–C 44)and orthorhombic structures (C 12–C 66;C 13–C 55;C 23–C 44)[26].Based on Ref.[4],compounds having a more positive Cauchy pressure tend to form bonds which are primarily metallic in nature,whereas compounds having a more negative Cauchy pressure form bonds which are more angular in character.Thus,the brittle nature of Mg 2Si and Mg 2Ge,can be correlated to their negative Cauchy pressures and thereby the angular character in their bonds.Simi-larly,the ductile nature of compounds like MgCu 2can be related to their high Cauchy pressures which thereby suggest a metallic character in their bonds.We have also verified the bond charac-teristics of the aforementioned compounds by calculating their electronic structure.In view of the reader’s interest,only results pertaining to MgCu 2and Mg 2Si are incorporated in thecurrentFig.4.Ductile/brittle properties of Mg based compounds based on elastic properties (references for literature can be obtained from Table 2).Table 3Fig.5.Calculated total density of states for MgCu 2.Fig.6.Partial density of states for (a)Mg and (b)Cu.S.Ganeshan et al./Intermetallics 17(2009)313–318316work,in order to highlight their corresponding metallic and cova-lent/ionic bond characteristics.The total electron density of states (DOS)for MgCu 2and its corresponding partial density of states (PDOS)are shown in Figs.5and 6.The features of these plots agree well with the previous calculations by Ref.[27].The charge density plot of MgCu 2in the (110)plane is shown in Fig.7.Mg itself has an outer electronic configuration of 3s 2.In MgCu 2,both these outer electrons of Mg get delocalized.Cu being a tran-sition metal has both the d and s electrons delocalized.The same can be seen in the charge density plot of MgCu 2Fig.7.There is a significant depletion of charge from the outer shells of both Mg and Cu,(blue color,for interpretation of the references to color in this figure,the reader is referred to the web version of this article).The electrons on the outer orbital further become delocalized to form a ‘‘sea of electrons’’as expected in a metallic bond.As there is no overlapping between the charge densities of Mg and Cu the possibility of a strong covalent bond between them is eliminated.Also,a finite DOS at the Fermi level in Fig.5further predicts MgCu 2to be metallic.The total electron density of states for Mg 2Si and its angular-momentum decomposition plots are shown in Figs.8and 9.In agreement with previous works [28–31],our results also show a mixture of ionic and covalent characters in the bonding of Mg 2Si.The build-up of charge around silicon atom as shown in its chargedensity plot in Fig.10,(red color,for interpretation of the references to color in this figure,the reader is referred to the web version of this article)and the charge depletion around Mg atom (thin blue lines,web version)essentially mark the ionic character in the bonds between Mg and Si.However,certain level of covalency in the system is also prominent from the strong charge accumulation between the Si–Si atoms.Moreover from the apparent hybridiza-tion between Mg(s)and Si(p)below the Fermi level as shown in Fig.9,a covalent character in Mg 2Si cannot be totally ignored.The nearest neighbor distance between Mg–Si,Mg–Mg and Si–Si are calculated as 2.753,3.17and 4.49Å,using a lattice constant of 6.35Å.These distances are analogous to those calculated for the covalent/ionic b (fluorite Mg 2Si)phase in Ref.[30].Thus,a mixture of both ionic as well as covalent bonding in Mg 2Si is observed based on its electronic structure which further supports the angular character in its bonds as mentioned earlier.4.Summarizing commentsElastic constants of 25binary Mg compounds have been calcu-lated from first-principles using the efficient stress–strain method.The elastic properties of these compounds have been correlated to their ductility and bond characteristics,thereby providing an understanding of their deformation behavior.The binding proper-ties of the Mg compounds as described from their elastic properties are further confirmed from their electronicstructures.Fig.7.Charge density plot of MgCu 2in the (110)plane.Fig.8.Calculated total density of states for Mg 2Si.Fig.9.Calculated angular-momentum decomposition for Mg 2Si.Fig.10.Charge density plot of Mg 2Si in the (110)plane.S.Ganeshan et al./Intermetallics 17(2009)313–318317AcknowledgementsThis work is funded by the National Science Foundation(NSF) through grant DMR-0510180.First-principles’calculations were carried out on the LION clusters at the Pennsylvania State University supported in part by the NSF grants(DMR-9983532,DMR-0122638, and DMR-0205232)and in part by the Materials Simulation Center and the Graduate Education and Research Services at the Pennsylvania State University.The authors would also like to express their sincere acknowledgements to James Saal,Arkapol Saengdeej-ing for helping us with their valuable calculations.References[1]Fine ME,Brown LD,Marcus HL.Scripta Metall1984;18:951–6.[2]Jhi SH,Ihm J,Louie SG,Cohen ML.Nature1999;399:132–4.[3]Pugh SF.Philos Mag1954;45:823–43.[4]Pettifor DG.Mater Sci Technol1992;8:345–9.[5]Cheng CH.J Phys Chem Solids1967;28:413–6.[6]Chung PL,Whitten WB,Danielson Gc.J Phys Chem Solids1965;26:1753–60.[7]Davis LC,Whitten WB,Danielson GC.J Phys Chem Solids1967;28:439–47.[8]Kadota Y,Ishibashi Y,Takagi Y.J Phys Soc Jpn1976;40:1017–20.[9]Sumer A,Smith JF.J Appl Phys1962;33:2283–6.[10]Wakabaya N,Shanks HR,Ahmad AAZ,Danielson Gc.Phys Rev B1972;5:2103–7.[11]Whitten WB,Chung PL,Danielson GC.J Phys Chem Solids1965;26:49–56.[12]Wu Y,Hu W.Eur Phys J B2007;60:75–81.[13]Shang S,Wang Y,Liu Z-K.Appl Phys Lett2007;90:101909.[14]Kohn W,Sham LJ.Phys Rev1965;140:1133–8.[15]Perdew JP,Burke K,Ernzerhof M.Phys Rev Lett1996;77:3865–8.[16]Kresse G,Furthmuller J.Phys Rev B1996;54:11169–86.[17]Kresse G,Furthmuller put Mater Sci1996;6:15–50.[18]Kresse G,Joubert D.Phys Rev B1999;59:1758–75.[19]Monkhorst HJ,Pack JD.Phys Rev B1976;13:5188–92.[20]Van de Walle A,Asta M,Ceder G.Calphad-Comput Coupling Ph DiagramsThermochem2002;26:539–53.[21]Methfessel M,Paxton AT.Phys Rev B1989;40:3616–21.[22]Blochl PE,Jepsen O,Andersen OK.Phys Rev B1994;49:16223–33.[23]Simmons G,Wang H.Single crystal elastic constants and calculated aggregateproperties:a handbook.Cambridge:M.I.T.Press;1971.[24]Villars P.Pearson’s handbook:crystallographic data for intermetallic phases.Materials Park,OH:ASM International;1997.[25]Mabuchi M,Kubota K,Higashi K.J Mater Sci1996;31:1529–35.[26]Born M,Huang K.Dynamical theory of crystal lattices.Oxford:OxfordUniversity Press;1954.[27]Chen W,Sun J.Physica B2006;382:279–84.[28]Baranek P,Schamps J.J Phys Chem B1999;103:2601–6.[29]Baranek P,Schamps J,Noiret I.J Phys Chem B1997;101:9147–52.[30]Froseth AG,Hoier R,Derlet PM,Andersen SJ,Marioara CD.Phys Rev B2003:67.[31]Imai Y,Watanabe A,Mukaida M.J Alloys Compd2003;358:257–63.[32]Zhang H,Saal J,Saengdeejing A,Wang Y,Chen L-Q,Liu ZK.Enthalpies offormation of Magnesium compounds from First-Principles calculations.Magnesium Technology.184Thorn Hill Road,Warrendale,PA:Metals,and Materials Society/AIME;2007.p.345–50.S.Ganeshan et al./Intermetallics17(2009)313–318 318。
镁合金资料文献
镁合金资料文献镁合金是实际应用中最轻的金属结构材料，它具有比重轻，比强度和比刚度高，阻尼性，导热性、切削加工型、铸造性能好，电磁屏蔽能力强，尺寸稳定，资源丰富，容易回收等一系列优点，所以，镁合金广泛应用也汽车工业，通讯电子业和航空航天业等领域，近年来镁合金产量在全球的年增长率高达20%，有极大的应用前景。
由于镁合金有极大的应用前景，所以在国内外掀起了一股研究镁合金的热潮。
在我国，镁资源及其丰富，我国是原镁生产大国，约占全球总产量的67%，而且是镁金属最大的出口国。
近年来，我国镁合金的研究和应用取得了举世瞩目的成绩，在高性能镁合金研究、加工装备开发以及镁合金深加工产品的开发应用方面都取得了很大的进展。
从镁产业的角度来讲，已经形成了从原材料到深加工一直到应用的完整产业链；从没研究开发的角度来讲，已经初步形成了从基础研究到应用研究一直到产品开发的完整科研开发体系，正从镁生产大国向镁研发和应用强国迈进。
但是，我国的镁工业仍然存在着很多问题：1）原镁生产技术落后，质量不稳定，镁中夹杂着大量有害元素，不满足很多生产工艺的技术要求；2）出口产品绝大多数是廉价的纯镁锭，利润低；3）原创性的研究成果太少。
镁合金产品加工中的关键技术和装备大部分靠国外引进。
2003年3月，科技部启动了“镁合金开发应用及产业化的前期战略研究，联合了4个研究院所，7所高校，20多家企业直接参与，建立了具有国际竞争力的镁合金高新技术产业群，将镁资源优势转化为经济优势！在863计划中，开展了包括耐热压铸镁合金及其应用技术，高强高韧镁合金及其技术开发，高性能变形镁合金及其应用技术，镁合金先进焊接技术，镁合金冲锻成型技术，镁合金锻造轮毂技术等研究。
而且，镁合金现在广泛应用于汽车行业。
国外的发展状态：北美、欧洲和日本等发达国家相继加大对镁合金开发和应用研究的投入。
德国1997年由联邦政府政府出资2500万马克的MADICA(Magnesium Die Casting)镁合金研究开发计划，主要研究压铸镁合金工艺、快速原型化与工具制造技术、切削加工技术，连接技术和半固态成形工艺。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
镁合金资料文献
镁合金是实际应用中最轻的金属结构材料，它具有比重轻，比强度和比刚度高，阻尼性，导热性、切削加工型、铸造性能好，电磁屏蔽能力强，尺寸稳定，资源丰富，容易回收等一系列优点，所以，镁合金广泛应用也汽车工业，通讯电子业和航空航天业等领域，近年来镁合金产量在全球的年增长率高达20%，有极大的应用前景。
由于镁合金有极大的应用前景，所以在国内外掀起了一股研究镁合金的热潮。
在我国，镁资源及其丰富，我国是原镁生产大国，约占全球总产量的67%，而且是镁金属最大的出口国。
近年来，我国镁合金的研究和应用取得了举世瞩目的成绩，在高性能镁合金研究、加工装备开发以及镁合金深加工产品的开发应用方面都取得了很大的进展。
从镁产业的角度来讲，已经形成了从原材料到深加工一直到应用的完整产业链；从没研究开发的角度来讲，已经初步形成了从基础研究到应用研究一直到产品开发的完整科研开发体系，正从镁生产大国向镁研发和应用强国迈进。
但是，我国的镁工业仍然存在着很多问题：1）原镁生产技术落后，质量不稳定，镁中夹杂着大量有害元素，不满足很多生产工艺的技术要求；2）出口产品绝大多数是廉价的纯镁锭，利润低；3）原创性的研究成果太少。
镁合金产品加工中的关键技术和装备大部分靠国外引进。
2003年3月，科技部启动了“镁合金开发应用及产业化的前期战略研究，联合了4个研究院所，7所高校，20多家企业直接参与，建立了具有国际竞争力的镁合金高新技术产业群，将镁资源优势转化为经济优势！在863计划中，开展了包括耐热压铸镁合金及其应用技术，高强高韧镁合金及其技术开发，高性能变形镁合金及其应用技术，镁合金先进焊接技术，镁合金冲锻成型技术，镁合金锻造轮毂技术等研究。
而且，镁合金现在广泛应用于汽车行业。
国外的发展状态：北美、欧洲和日本等发达国家相继加大对镁合金开发和应用研究的投入。
德国1997年由联邦政府政府出资2500万马克的MADICA(Magnesium Die Casting)镁合金研究开发计划，主要研究压铸镁合金工艺、快速原型化与工具制
造技术、切削加工技术，连接技术和半固态成形工艺。
1999年9月，日本文部科学省资助开展了了“先进镁合金科学技术计划（PSTAM）”项目意在研究未来镁
合金应用的基础科学问题：1)结构控制;2)表面改性；3）生态技术；4）新型功能与应用的开发。
2001年，美国汽车材料公司与美国能源部为判定开发镁合金强力发动机的可行性与必要性而提出了用于动力系统的镁合金逐渐开发项目。
镁合金技术的新发展：
1）耐热镁合金，耐热性差是阻碍现有镁合金广泛应用的主要原因之一，温度过高，镁合金的强度和抗蠕变性能大幅下降，使它难以作为关键零件材料在汽车等工业中得到更广泛利用目前国外将耐热镁合金研究开发作为重要突破方向，提高镁合金在150—250°C时的强度和抗蠕变性能。
2）耐蚀镁合金，严格限制镁合金中的Fe、Cu、Ni等杂质元素的含量，控制Fe /Mn比，所得到的镁合金有更好的耐蚀性。
3）阻燃镁合金，镁合金在熔炼浇注中容易发生剧烈的氧化燃烧，实践证明，溶剂保护法和SF/SO/CO/Ar等气体保护法是行之有效的阻燃方法。
4）高强高韧镁合金，在MG—ZN和MG—Y合金中加入GA、ZR可显细化晶粒，提高其抗拉强度和屈服强度。
另外，通过快速凝固、粉末冶金、高挤压比及等通道角挤(ECAE)等方法，也可以使镁合金的晶粒处理得很细，从而获得高强度、高塑性甚至超塑性。
5）变形镁合金，经变形的镁合金可获得更高的强度，更好的延展性及多样化的力学性能，可以满足不同场合结构件的使用要求。
6）镁合金熔炼技术，通常情况下用SF6气体熔炼镁合金，但其温室效应是CO2的23900倍，需找到可代替的熔炼气体。
7）镁合金的成形技术，常用成形方法有压铸，半固态铸造、挤压铸造、挤压、扎制等，其中，镁合金80%是通过铸造方法获得。
各种功能性的镁合金在工业中都发挥着巨大的作用。
镁合金具有一些列优良的性能，在汽车工业，通讯电子业，航空航天业等领域得到了日益广泛的应用，镁合金及其成形技术也得到快速发展，镁合金的性能不断得到提高，镁合金熔炼技术、成形技术和表面处理技术等领域得到不断发展、新的技术和装备也不断被开发和应用，展示了镁合金的光明前景。
我国有丰富的镁资源，但是在技术应用方面与国外还有一定的差距，我们应该把我国的镁资源优势转化为技术、经济优势。
促进国民经济的发展。
参考文献：
【1】镁合金研究开发现状与展望——伤害交通大学轻合金精密成型国家工程研究中心（王渠东、丁文江）
【2】曲家惠、岳明凯、黄涛沈阳理工大学学报 AZ31镁合金在不同挤压比和挤压
温度下的织构演变2 0 0 9 年4 月
【3】张丁非、石国梁、赵霞兵、齐福刚、重庆大学材料科学与工程学院Ｍｎ元素在Ｍｇ－Ｚｎ－Ｍｎ合金中演变形式和作用的研究＊
【4】张丁非，赵霞兵，石国梁，齐福刚国家镁合金材料工程技术研究中心Zn 含量及热处理对Mg-Zn-Mn 变形镁合金
显微组织和力学性能的影响2011 年 3 月
【5】聂保新，乔军，张永彬粗晶粒铸扎AZ31镁合金的高温拉伸性能辽宁科技大学学报2011、10
【6】李艳辉, 李保成, 尹从娟挤压比和挤压温度对AZ31 镁合金组织性能的影响中北大学【】蔡薇, 齐亮, 饶克挤压温度对AZ31 镁合金组织性能的影响江西理工大学材料与化学工程学院 2008、06
【7】高玉华1, 2 高级工程师陈传祥1, 2镁合金熔炼、铸造过程的危险性分析X江苏科技大学先进焊接技术省级重点实验室2 0 0 6 年5 月
【8】刘英, 李元元, 张卫文, 罗宗强, 张大童镁合金的研究进展和应用前景华南理工大学,
【9】于建民，张治民，张宝红塑性变形对AZ31 镁合金晶粒细化的影响中北大学材料科学与工程学院2009 年第38 卷第15 期
【10】戴庆伟1 , 张丁非1, 2 , 袁炜Researches on Ext rusion, Micros tructure and Mechanical
Propert ies of New Mg-Zn-Mn Alloy国家镁合金材料工程技术研究中心2008 年4 期【11】WANG Hai-lu1, WANG Guo-jun2, HU Lian-xi1
Effect of hot rolling on grain refining and mechanical
properties of AZ40 magnesium alloy
School of Materials Science and Engineering, Harbin Institute of Technology 【12】HU Lian-xi1, WANG Guo-jun2, WANG Er-de1
Microstructure refining and property improvement of
ZK60 magnesium alloy by hot rolling
Technical Center, Northeast Light Alloy Co. Ltd., Received 10 May 2011;
【13】[17] GAO X, NIE J F. Characterization of strengthening precipitate phased in a Mg-Zn alloy [J]. Scripta Mater, 2007, 56(8): 645−648.。