Laasraoui­Jonas 位错密度模型结合元胞自动机模拟 AZ31镁合金动态再结晶

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Laasraoui­Jonas(L­J)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 L­J 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。%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 Laasraoui­Jonas (L­J) dislocation density equation can be employed to calculate the dislocation evolution during dynamic recrystallization of AZ31 magnesium alloy. The results simulated from modified L­J dislocation density model coupled with Cellular Automata (CA) method are well matched with the experimental results.