中文摘要：

通过Gleeble-3500热压缩试验机对AZ31镁合金进行热压缩实验，得到温度为300、350、400、450和500℃，应变速率为0．03、0．3、和3s1的流变应力曲线。对流变应力曲线进行图形变换求解出不同应变速率下的回复参数r，求得的回复参数的自然对数lnr与温度的倒数1／T成线性相关。结果表明：可以采用修正的Laasraoui—Jonas（L—J）位错密度模型计算AZ31镁合金动态再结晶过程中的位错密度演变；修正的L-J位错密度模型结合元胞自动机（CA）能精确地模拟位错密度动态再结晶过程。

英文摘要：

The hot compression tests of AZ31 magnesium alloy were performed on the Gleeble-3500 machine to obtain the flow stress curves under temperatures of 300, 350, 400, 450 and 500 ℃ and strain rates of 0.03, 0.3 and 3 s-1. The recovery parameter （r） under different strain rates were calculated by transformation of flow stress curves. A linear correlation between lnr and 1/T was observed. The results show that the modified Laasraoui-Jonas （L-J） dislocation density equation can be employed to calculate the dislocation evolution during dynamic recrystallization of AZ31 magnesium alloy. The results simulated from modified L-J dislocation density model coupled with Cellular Automata （CA） method are well matched with the experimental results.