文档介绍：中国科技论文在线

ZK40 镁合金高应变速率高温压缩变形行为
和组织演变#
吴远志,严红革,陈吉华**
(湖南大学材料科学与工程学院, 长沙 410082)
摘要:在变形温度 250-400℃、应变速率 -50/s 的条件下,研究了 ZK40 镁合金高温压缩
变形行为和组织演变,并通过建立本构方程得到了 ZK40 镁合金热变形激活能和应力指数。
结果表明:ZK40 合金热变形激活能和应力指数分别为和 ;低应变速率下
(≤1/s)再结晶主要在晶界上发生,高应变速率下(≥10/s)在晶界和孪晶上都产生大量的再结
晶晶粒,得到比低应变速率更均匀的变形组织,在高应变速率条件下合金热加工成形性能好;
应变速率为 20/s 和 50/s 时,随着温度的升高再结晶晶粒出现异常长大,而应变速率为 10/s
时,再结晶晶粒度在所有的温度范围内保持一致;ZK40 合金最佳热加工工艺参数为 250-400
℃和 10/s。
关键词: 镁合金;高应变速率;热压缩;显微组织;动态再结晶
中图分类号:TG3

Hot deformation behavior and microstructure evolution of
ZK40 magnesium pressed at high strain rates
WU Yuanzhi, YAN Hongge, CHEN Jihua
(College of Materials Science and Engineering, Hunan University, Changsha 410082)
Abstract: The pression deformation behavior and microstructure evolution of the
homogenized ZK40 magnesium alloy were investigated in the temperature range of 250-400℃ and at
the strain rate range of -50/s. The activation energy Q and stress exponent n deduced to be
and by carrying out constitutive analysis. At the lower strain rate (≤1/s), DRX
developed mainly at the grain boundaries. At the higher strain rate (≥10/s), DRX developed
extensively at the grain boundaries and twins, resulting in a more homogeneous microstructure than the
other conditions. The hot deformation characteristics of ZK40 exhibited an abnormal relationship wi