AZ41M镁合金动态再结晶组织演变模拟

Simulation of microstructure evolution of AZ41M magnesium alloy during dynamic recrystallization

在变形温度300～450℃,应变速率0.005～1 s-1条件下,采用Gleeble-1500D试验机对AZ41M镁合金进行热压缩实验;处理实验数据,求解不同变形条件下的动态回复软化率系数r,分析了温度和应变速率等工艺参数对r的影响;基于实验数据,建立了Laasraoui-Jonas（L-J）位错密度模型,借助Deform-3D软件对合金热压缩时的组织演变过程进行模拟,并将模拟结果与实验微观组织进行对比。结果表明,动态回复软化率系数r随温度升高而增大,随应变速率增加而降低;组织模拟结果与实验结果基本吻合,该位错密度模型能准确模拟合金动态再结晶过程中的微观组织演变。

The hot compression tests of AZ41 M magnesium alloy were performed on a Gleeble-1500 D machine under the temperature of300-450 ℃ and strain rate of 0. 005-1 s- 1. The recovery parameter（ r） under different deformation conditions were obtained by dealing with the experimental data and the effects of temperature and strain rate on the recovery parameter were analyzed. The Laasraoui-Jonas（ LJ） dislocation density model was established based on the experimental results. The microstructure evolution of AZ41 M magnesium alloy was simulated via Deform-3D software,and then the simulation results were compared with that of the hot compression test. The results show that the recovery parameter increases with the increasing of temperature and decreases with the increasing of strain rate. The simulation results correlate well with the experimental results,thereby confirming that the L-J dislocation density model can provide an excellent prediction for the microstructure evolution of AZ41 M magnesium alloy during dynamic recrystallization.