镁薄板合金成形的可锻性和可成形性的加工技术摘要金属成型和金属成形机床的新发展，显示了镁薄片具有优秀的模铸性能，如果工艺是在高温下传导。

对镁薄片成型的相应的机械性能的估价，已经在各种各样的温度和应变率的条件下进行的单轴向拉力的测试。

镁合金az31b、az61b的拉深测试和m1在200-250温度范围之间都有很好可成形性，除温度之外，已经研究出的极限拉延比也影响模铸的速度。

产生的结果得出有可能由镁薄片合金混合物代替传统的铝和钢薄片的结论。

⒈引言为了减少燃料消耗、一般已经有的成就是减少汽车构造的重量的，增加重量轻的物资的使用，在这个条件下、镁合金具有对工商企业集团有特殊的使用价值，因为他们的密度低，只有1.74 g／cm3。

不久的将来镁合金将成为汽车零件模铸的主要地材料。

模具铸件技术允许放弃制造过程中复杂的几何结构。

然而，这个部分的机械性能经常不能满足机械性能的必要条件，（例如耐久强度和延性）。

一种有希望能替换的材料，毫无疑问是将模铸工艺带进简便化，那部分对机械性能和细粒的微观结构有利的没有气孔的制造技术。

然而、一种广泛被应用的模铸技术在镁合金的成型的工艺中受到了限制，模铸技术和适当的工艺参数的不完善而不得不应用（2,3）。

镁薄板金属部件的应用对汽车车身的构造提供一个很大的潜力。

通常、汽车的车身完全由板料冲压和表现大约25%飞行器质量组成。

所以，镁薄片替代传统的材料应用，将导致重量减轻的实质。

⒉镁薄片的塑料性质镁合金在室温下显示出可成形性的极限，这个六方晶体和孪晶体的倾向是唯一的允许有限的形变。

那不同地定向微晶在独立基础滑动平面显示出畸形，导致一个相互的滑动障碍（４、５）。

通过应用的温度完善可以对模铸品质进行可观的改善！在200 -225温度范围里的可成型性的提高具有很好的可观性（依靠合金成分）见文献《６》的研究。

在棱形滑动面的六方形结构的热活化性中发现了这个效果，见文献《７》。

2.1成型温度对流动应力的影响一种对镁薄片畸形性质要求的测定的详细研究的金属的特征值同样各向异性或流动曲线见《８、９》。

因为在这个领域里的系统研究表明对各种各样的镁合金的温度和应变率的可塑性的大量的调查涉及金属成型和金属成形机床的原理的影响不是可利用的（ifum）。

图1；显示镁金属az31b在不同温度的流动曲线、显然那应力和可能的拉紧力，大量地依靠在那成型温度上。

在2008c以上温度范围内流动应力的减少随温度的变化而的变化。

3 镁合金的拉深为了要研究镁薄片在不同的成型温度的可模锻性，在IFUM与圆筒形工具系统中进行拉深测试，图3显示在50c的温度的拉深测试的结果。

然而那az31b在低点b01：45可能的拉深比率（拉深：30mm）合金az61b和m1显示早的破裂，使用b01：6的拉深比率，AZ31 B 显示与AZ61 B 和 M 1 类似的破裂，这些测试确定镁合金的可模锻的低点温度。

然而，调查结果显示镁合金在高温的情况下有非常好的模锻性。

发现在2008c温度下az31b的成型温度具有最大bo的拉深比率，az61b 和m1显示铝合金b0的最大价值提高到2：20：2.25.，AlMg4.5 Mn0.4 的比较显示铝合金在室温下非常容易模锻,镁合金的增加的拉深比率在低点温度与提高温度的比较，结果表明从可拉长的测试显示那应力比率在镁合金的机械道具的重要的影响力。

参考文献。

[1] H. Kehler et al., Partikelversta¨rkte Leichtmetalle, Metall Band, 49,Heft 3, 1995.[2] E. Doege, K. Dro¨der, St. Janssen, Leichtbau mit Magnesiumknetlegierungen— Blechumformung und Pra¨zisionsschmieden TechnischerMg-Legierungen, Werkstattstechnik, Band 88, Heft 11/12,1998.[3] E. Doege, K. Dro¨der, F.P. Hamm, Sheet Metal Forming ofMagnesium Alloys, Proceedings of the IMA-Conference on MagnesiumMetallurgy, Clermont-Ferrand, France, October 1996.[4] H.J. Bargel, G. Schulze, Werkstoffkunde, VDI-Verlag GmbH,Du¨sseldorf, 1988.[5] C.S. Roberts, Magnesium and Its Alloys, Wiley, New York, 1960.[6] G. Siebel, in: Beck (Ed.), Technology of Magnesium and Its Alloys,Hughes, London, 1940.[7] N.N.: Magnesium and Magnesium Alloys, Ullmann’s Encyclopediaof Industrial Chemistry, Reprint of Articles from 5th Edition, VCH,Weinheim, 1990.[8] E. Doege, K. Dro¨der, Processing of magnesium sheet metals by deepdrawing and stretch forming, Mat. Tech. 7–8 (1997)19–23.[9] E. Doege, K. Dro¨der, St. Janssen, Umformen von Magnesiumwerkstoffen,DGM-Fortbildungsseminar, Clausthal-Zellerfeld, Oktober1998, pp. 28–30.[10] L. Taylor, H.E. Boyer, in: E.A. Durand, et al. (Eds.), MetalsHandbook, 8th Edition, Vol. 4, American Society of Metals, Cleveland, OH, 1969.Sheet metal forming of magnesium wrought magnesium wrought alloys— formabilityand process technologyAbstractNew developments at the for Metal Forming and Metal Forming Machine Tools show that magnesium sheets possess excellent forming behavior, if the process is conducted at elevated temperatures. For the evaluation of mechanical properties relevant for forming of magnesium sheets, uni axial tensile tests have been carried out at various temperatures and strain rates.Deep drawing tests with magnesium alloys AZ31B, AZ61B, and M1 show very good formability in a temperature range between 200 and 2508C. Besides temperature, the influence of forming speed on limit drawing ratio has been investigated. The obtained results lead to the conclusion that it is possible to substitute conventional aluminum and steel sheets by using magnesium sheet metal wrought alloys.1. IntroductionIn order to reduce fuel consumption, general efforts have been made to decrease the weight of automobile constructions by an increased use of lightweight materials. In this framework, magnesium alloys are of special interest because of their low density of 1.74 g/cm3.Presently, magnesium alloys for the use as automobile parts are mainlyprocessed by die casting. The die casting technology allows the manufacturing of parts with complex geometry. However, the mechanical properties of these parts often do not meet the requirements concerning the mechanical properties (e.g. endurance strength and ductility). A promising alternative has to be seen in components that are manufactured by forming processes. The parts manufactured by this technology are characterized by advantageous mechanical properties and fine-grained microstructure without pores [1]. However, a widespread use of forming technologies for the processing of magnesium alloys is restricted because of insufficient knowledge about the forming technologies and suitable process parameters that have to be applied [2,3].Automotive body constructions offer a great potential for the application of magnesium sheet metal components.In general, the automotive body completely consists of sheet metal parts and represents a share of about 25% of the entire vehicle mass. Therefore, the substitution of conventional sheet materials by magnesium sheets would lead to essential weight savings in this application.2. Plastic material properties of magnesium sheetsMagnesium alloys show a limited formability at room temperature. This results from the fact that the hexagonal crystal structure and the low tendency to twinning only allow limited deformations. The differentlyorientated crystallites only show a deformation on the individual base slip plane, which leads to a mutual slip hindrance [4, 5]. A considerable improvement of the forming qualities can be achieved by applying temperature. The considerable increase in formability that occurs in the temperature range from 200 to2258C (depending on alloying composition) was investigated by Siebel [6]. The reason for this effect was found in the thermal activation of pyramid sliding planes in the hexagonal structure [7].2.1. Influence of forming temperature on flow stressA detailed evaluation of the deformation properties of magnesium sheets requires the determination of the material’s characteristic values like anisotropy or flow curves [8, 9].Because systematic investigations in this area are not available, extensive investigations concerning the influence of temperature and strain rate on plastic properties of various magnesium alloys were performed atInstitute for Metal Forming and Metal Forming Machine Tools (IFUM). Fig. 1 displays flow curves of magnesium sheet material AZ31B at different temperatures, determined in the uniaxial tensile test according to EN 10002, part 5.It is obvious that the stresses and possible strains largely depend on the forming temperature. The decrease of flow stresses in the temperature range above 2008C attributes to temperature-dependent relaxation.3. Deep drawing of magnesium alloysIn order to investigate the formability of magnesium sheets, deep drawing tests at different forming temperatures were carried out at IFUM with a cylindrical tool system.Fig. 3 shows the results of deep drawing tests at a temperature of 50C. Whereas the deep drawing of the alloy AZ31B using a low drawing ratio of b0 1:45 was possible (drawing depth: 30 mm), the alloys AZ61B and M1 showed early fracture. Using drawing ratio of b0 1:6, AZ31B showed fracture similar to AZ61B and M1. These tests confirm the low formability of magnesium alloys at low temperature.However, the investigated magnesium alloys show very good formability at higher temperature ，The maximum limit drawing ratio of b0 ; max 2:52 was detected for AZ31B at a forming temperature of 2008C. AZ61B and M1 show maximum values of approximately b0 ; max 2:20 up to 2.25. The values of the aluminum alloy AlMg4.5Mn0.4 are displayed for comparison. Due to the good formability of the aluminum alloy at room temperature, the increase in limit drawing ratio with rising temperature is low compared to the magnesium alloys.The results gained from the tensile tests showed the significant influence of strain rate on themechanical properties of magnesium alloys.[1] H. Kehler et al., Partikelversta¨rkte Leichtmetalle, Metall Band, 49, Heft 3, 1995.[2] E. Doege, K. Dro¨der, St. Janssen, Leichtbau mit Magnesiumknetlegierungen— Blechumformung und Pra¨zisionsschmieden TechnischerMg-Legierungen, Werkstattstechnik, Band 88, Heft 11/12,1998.[3] E. Doege, K. Dro¨der, F.P. Hamm, Sheet Metal Forming of Magnesium Alloys, Proceedings of the IMA-Conference on Magnesium Metallurgy, Clermont-Ferrand, France, October 1996.[4] H.J. Bargel, G. Schulze, Werkstoffkunde, VDI-Verlag GmbH,Du¨sseldorf, 1988.[5] C.S. Roberts, Magnesium and Its Alloys, Wiley, New York, 1960.[6] G. 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Schmoeckel, Temperaturgefu¨hrte Prozeßsteuerung beim Umformenvon Aluminiumblechen, EFB-Forschungsbericht, Nr. 55, 1994.[14] H. Beißwa¨nger, Warmziehen von Leichtmetallblechen, Mitteilung der Forschungsgesellschaft Blechverarbeitung, Nr. 27, 1950.[15] E. Kursetz, Die Anwendung von Wa¨rme bei der Herstellung von Blechformteilen aus Schwer Umformbaren Werkstoffen, Ba¨nder Bleche Rohre, Nr. 5, 1974.[16] O. Heuel, Optimierung der Werkzeugtemperatur Durch Richtige Auslegung und Installation der Temperiersysteme, Der Stahlformenbauer, Heft 1, 1992.11。