Hot deformation behavior and workability of pre-extruded ZK60A magnesium alloy  

挤压态ZK60A镁合金高温变形行为和加工性能（英文）

作　　者：汪时宜 高磊 Alan A.LUO 李德江[1] 曾小勤[1] 

机构地区：[1]上海交通大学轻合金精密成型国家工程研究中心,上海200240 [2]通用汽车中国研究院,上海201206 [3]College of Engineering,the Ohio State University

出　　处：《Transactions of Nonferrous Metals Society of China》2015年第6期1822-1830,共9页中国有色金属学报（英文版）

基　　金：Projects(51171113,51301107) supported by the National Natural Science Foundation of China

摘　　要：The hot deformation behavior and workability of pre-extruded ZK60A magnesium alloy were investigated by compression tests in the temperature range of 250-450 ℃and the strain rate range of 0.001-10 s 1. The constitutive equation for the pre-extruded ZK60A alloy can be described by hyperbolic sine function. Processing maps were constructed from true strains of -0.2 to -0.8. The alloy experienced complete dynamic recrystallization （DRX） and showed good workability in the temperature range of 300-400 ℃ and the strain rate range of 0.01-0.001 s-Z, where hot working in pre-extruded ZK60A, such as forging, can be carried out. For large deformation to true strain of over -0.5, strain rates above 0.1 s-1 are not recommended at all temperatures, where flow instability such as local strain concentration, twinning deformation, abnormal grain growth, micro-cracks, and shear fracture were observed. Climb-controlled dislocation creep dominates both the plastic deformation and nucleation of DRX of the pre-extruded ZK60A magnesium alloy.通过在温度为250~450°C和应变速率为0.001~10 s-1条件下进行压缩测试,研究挤压态ZK60A镁合金的高温变形行为和加工性能。ZK60A镁合金的本构方程可以用双曲正弦函数进行描述。在真应变为-0.2^-0.8下构建热加工图。在300~400°C以及0.01~0.001 s-1应变速率下,材料完全再结晶(DRX)并显示出良好的加工性能。ZK60A镁合金高温加工,例如锻造,可以进行。在变形量大于-0.5以及应变速率高于0.1 s-1时,实验观察到流变失稳现象,例如局部应变集中、孪生变形、晶粒异常长大、微裂纹和切变断裂,不推荐进行加工。攀移控制的位错蠕变主导ZK60A镁合金的塑性变形以及动态再结晶形核。

关 键 词：pre-extruded ZK60A magnesium alloy hot deformation processing map constitutive equation WORKABILITY 

分 类 号：TG146.22[一般工业技术—材料科学与工程]