(1. 中南大学 材料科学与工程学院 长沙 410083；
2. 湖南工学院 机械工程系 衡阳 421002)
摘 要: 研究Mg-8Gd-3Y-0.6Zr合金热压缩过程的动态再结晶规律。对该合金在变形温度为623~773 K、应变速率为0.01~1 s−1条件下进行单向压缩实验，用金相显微镜、场发射扫描电子显微镜及织构测试仪对压缩后的合金组织与晶体取向进行分析。结果表明：曲线的峰值应力、稳态流动应力均随Zener-Hollomon (Z)参数的增加而增加；变形温度的升高以及应变速率的提高均能减弱{0001}基面织构，强化 柱面织构；动态再结晶晶粒尺寸随Z参数的增加而减小。根据实验结果，该合金在热轧时ln(Z)宜控制在28~32之间，变形温度在723~773 K之间。
关键字: 镁合金；热压缩；动态再结晶；Zener-Hollomon参数；织构
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Department of Mechanical Engineering, Hunan Institute of Technology, Hengyang 421002, China）
Abstract:The regularity of dynamic recrystallization in Mg-8Gd-3Y-0.6Zr alloy during hot-compression was investigated. For this purpose, the uniaxial compression was conducted at different deformation temperatures (from 623 K to 773 K) and various strain rates (from 0.01 s−1 to 1 s−1). The microstructure and macrotexture after compression were studied by optical microscope (OM), scanning electron microscopy (SEM) and X-ray texture measurement. The results show that the peak stress and the steady-state flow stress become higher with increasing Zener-Hollomon parameter (Z); Increasing deformation temperature or strain rate can weaken the {0001} basal texture and strengthen the prismatic texture; the grain size of dynamic recrystallization becomes smaller with increasing Z parameter. Therefore, ln(Z) ranging in 28−32 and the deformation temperature ranging in 723−773 K are proposed for hot-rolling of Mg-8Gd-3Y-0.6Zr alloy.
Key words: magnesium alloy; hot-compression; dynamic recrystallization; Zener-Hollomon parameter; macrotexture
