Hot compression behavior and processing map of cast Mg-4Al-2Sn-Y-Nd alloy  

铸造Mg-4Al-2Sn-Y-Nd镁合金的热压缩行为与加工图（英文）

作　　者：王晶[1] 史宝良[1] 杨院生[1,2] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]山东省科学院新材料研究所,济南250014

出　　处：《Transactions of Nonferrous Metals Society of China》2014年第3期626-631,共6页中国有色金属学报（英文版）

基　　金：Project(2011BAE22B01-1)supported by the National Key Technology R&D Program;Project(2011DFA50903)supported by the International Science&Technology Cooperation Program of China

摘　　要：The plastic flow behavior of a newly developed high ductility magnesium alloy, Mg-4Al-2Sn-Y-Nd, was investigated by hot compression from 200 to 400 ℃ with a strain rate of 1.5×10-3 to 7.5 s-1. The results reveal that the strain rate sensitivity factor （m） of the alloy is much lower than that of the AZ31 alloy, which implies that the alloy should be more suitable for processing at high strain rate. The constitutive relationship of the alloy deformed at elevated temperature was obtained by plotting the experimental data. The stress exponent of the alloy is 10.33, which reveals that climb-controlled dislocations creep is the dominated deformation mechanism. The processing-map technique was used to determine the practical processing window. The proper deformation temperature and strain rate of the cast alloy were determined as 350-400 ℃ and 0.01-0.03 s-1, respectively.利用热压缩实验研究一种新型的具有优异室温塑性的Mg-4Al-2Sn-Y-Nd镁合金的高温流变行为，变形温度为200～400℃，应变速率为1.5×10-3～7.5 s^-1。结果表明：合金的应变速率敏感因子（m）在不同变形温度下均明显小于AZ31镁合金的m值，因此该合金适合在高应变速率下进行热加工。在真应力-应变曲线基础上，建立Mg-4Al-2Sn-Y-Nd 镁合金高温变形的本构方程，并计算得到合金的应力指数为10.33，表明合金在高温下主要的变形机制为位错攀移机制。同时，利用加工图技术确定合金的最佳高温变形加工窗口，即变形温度在350～400℃之间，应变速率在0.01～0.03 s^-1。

关 键 词：magnesium alloy uniaxial compression apparent activation energy processing map 

分 类 号：TG292[金属学及工艺—铸造]