(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 针对半连续铸造的AZ31B镁合金，采用Gleeble−1500热/力模拟机在变形温度为473~723 K、应变速率为0.01~10 s−1、最大变形量为80%条件下进行热/力模拟研究；结合热变形后的显微组织，分析合金力学性能与显微组织之间的关系。结果表明：当变形温度一定时，流变应力和应变速率之间存在对数关系，并可用包含Arrheniues项的Z参数描述半连续铸造的AZ31B镁合金热压缩变形的流变应力行为；实验合金在523 K时开始发生动态回复；随着变形温度的升高和应变速率的降低，动态再结晶开始对AZ31B合金的变形行为产生明显影响，在变形温度623 K以上的各种应变速率下，AZ31B镁合金易变形。
关键字: AZ31B镁合金；热压缩变形；流变应力；组织演变
semi-continuous cast AZ31B magnesium alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The deformation behaviors of AZ31B magnesium alloy at different strain rates of 0.01−10 s−1 and different deformation temperatures of 473−723 K were investigated by using Gleeble-1500 simulator with a maximum strain of 80%. The microstructure of the experimental alloy was studied after the hot-compression procedure. The result shows that the relationship among the peak flow stress, strain rate and temperature can be described by Z parameter containing Arrheniues item. The strain rate and the deformation temperature are the key parameters affecting the alloy deformation activation energy. Dynamic recovery starts at the temperature of 523 K. With increasing the temperature or decreasing the strain rate, the dynamic recrystallization procedure has great influence on the deformation behavior. The alloy is easy to deform at the temperature above 623 K.
Key words: AZ31B magnesium alloy; hot-compressive deformation; flow stress; microstructure evolution
