(1. 湖南大学 汽车车身先进设计制造国家重点实验室，长沙 410082；
2. 湖南大学 机械与运载工程学院，长沙 410082)
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3 s-1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。
关键字: AZ31镁合金；L-J位错密度模型；动态再结晶
（1. State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University,
Changsha 410082, China;
2. College of Mechanical and Vehicle Engineering, Hunan University, ）
Abstract: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.
Key words: AZ31 magnesium alloy; L-J dislocation density model; dynamic recrystallization
