Microstructure and mechanical properties of AZ61 magnesium alloy parts achieved by thixo-extruding semisolid billets prepared by new SIMA  

新SIMA制备坯料触变挤压AZ61镁合金零件的组织与性能(英文)

作　　者：姜巨福[1] 王迎[2] 柳君[1] 曲建俊[2] 杜之明[1] 罗守靖[1] 

机构地区：[1]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [2]哈尔滨工业大学机电工程学院,哈尔滨150001

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第3期576-585,共10页中国有色金属学报（英文版）

基　　金：Project(51075099) supported by the National Natural Science Foundation of China;Project(E201038) supported by the Natural Science Foundation of Heilongjiang Province,China;Project(20090460884) supported by the China Postdoctoral Science Foundation;Projects (HIT.NSRIF.2013007 and 2012038) supported by the Fundamental Research Funds for the Central Universities,China;Project (2011RFQXG010) supported by the Harbin City Young Scientists Foundation under the Grant;Project(LBH-T1102) supported by the Specially Postdoctoral Science Foundation of Heilongjiang Province,China

摘　　要：New strain induced melt activation（new SIMA） method was employed to prepare high-quality semisolid billet of AZ61 magnesium alloy.Optical microscopy and tensile test were used to study the microstructure and mechanical properties of the thixo-extruded component.The results showed that the optimal process parameters for achieving the complete filling status involved the applied pressure of 784 MPa,the pressure holding time of 90 s and the die temperature of 450 ℃.Compared to semisolid isothermal treatment,high mechanical properties such as the tensile strength of 300.5 MPa and elongation of 22% and fine microstructure were obtained in the thixo-extruded parts.With increasing the isothermal temperature and holding time,the tensile strength and elongation were increased firstly and then decreased.When the press pass was increased from 1 to 4,the tensile strength and elongation of the thixo-extruded parts were greatly enhanced and microstructure was refined obviously.新应变诱导熔化激活法被用来制备高质量的AZ61镁合金半固态坯料。利用光学显微镜和拉伸实验,研究触变挤压成形零件的微观组织与力学性能。结果表明:当施加的压力为784MPa,保压时间为90s,模具温度为450℃时,半固态坯料能够完全充填模具型腔。与半固态等温处理方法相比,新SIMA法制备的半固态坯料触变挤压成形零件的抗拉强度和伸长率分别为300.5MPa和22%;并且成形零件的微观组织晶粒细小、组织均匀。随着等温处理温度的升高和保温时间的延长,成形零件的抗拉强度和伸长率先增加后降低。当挤压道次从1增加至4时,成形零件的抗拉强度和伸长率明显增加。

关 键 词：AZ61 magnesium alloy semisolid billets new strain induced melt activation THIXO-EXTRUSION 

分 类 号：TG379[金属学及工艺—金属压力加工]