Mg-11.21Gd-2.26Y-0.44Zr稀土镁合金热变形行为

Deformation behavior of Mg-11.21Gd-2.26Y-0.44Zr alloy at elevated temperatures

采用差热分析、金相显微镜等手段,分析了Mg-11.21Gd-2.26Y-0.44Zr稀土镁合金的微观组织,结果发现,在温度530℃均匀化热处理4h,可使大部分合金元素固溶。采用Gleeble3800热模拟实验机,在温度为320℃～480℃、应变速率为0.001s-1～0.1s-1、最大变形程度为60%的条件下,对该镁合金进行热压缩实验,结果表现,材料流变应力行为和显微组织受到变形温度和变形速率的严重影响;合金的流动应力可以采用Sellars方程形式描述;计算出的变形激活能为225.67kJ.mol-1。

The microstructure of Mg-Gd-Y-Zr RE-containing magnesium alloy was investigated by means of differential thermal analysis and metallo-graphic microscope.The results show that the majority of alloy elements turn into solid solution through uniform heat treatment at 530℃ for 4h.Hot compression tests of Mg-11.21Gd-2.26Y-0.44Zr alloy were performed with Gleeble3800 thermal modeling tester at strain rate 0.001s^-1～0.1s^-1,deformation temperature 320℃～480℃,and the deformation degree not exceeding 60%.The results show that the flow stress behavior and microstructures strongly depend on the deformation temperature and strain rate during hot compression deformation;the flow stress can be calculated by Sellars equation;the activation energy during hot deformation is 225.67kJ·mol^-1 by calculation.