AZ31镁合金高应变速率轧制宏微观仿真

Macro-micro Simulation of AZ31 Magnesium Alloy Under High Strain Rate Rolling

本工作通过构建宏观有限元模型和微观动态再结晶模型,对AZ31镁合金在300~400℃、平均应变速率为10~29 s^(-1)的条件下进行高应变速率轧制宏微观模拟。对比实验结果的结论如下:随着平均应变速率的增加,模拟的轧板宽度方向等效应力差值和宏观边裂长度都减小,等效应力差值越大,边裂长度越长,宏观模拟结果与实验一致;采用微观动态再结晶模型、宏观有限元历史加载耦合元胞自动机(CA),模拟AZ31镁合金高应变速率轧制中的动态再结晶过程,微观模拟结果与实验吻合;随着平均应变速率的增加,再结晶越完全,使得应力集中被释放,边裂长度减小。通过建立AZ31镁合金高应变速率轧制多尺度宏微观仿真模型,能够精确模拟仿真高应变速率轧制过程,对镁合金高应变速率轧制的精确控制提供了新的思路。

Macroscopical finite element model and microcosmic dynamic recrystallization model were established to simulate high strain rate rolling of AZ31 magnesium alloy over the temperature ranges 300℃ to 400℃ with average strain rates of 10-29 s^(-1).The results according to the comparison between simulated results and experimental results show that with increasing the average strain rate,both the equivalent stress difference of the simulated rolled plate along the width direction and the macro crack length decrease.The greater the difference in the equivalent stress,the longer the crack length.The results of macro simulation agree well with the experimental results.Dynamic recrystallization of AZ31 magnesium alloy during high strain rate rolling was simulated using micro-dynamic recrystallization model and macro-finite element history loa-ding coupled cellular automata(CA).With strain rate increasing,recrystallization is gradually completely,followed by dissipation of stress concentration,finally causing the decrease of crack length.The high strain rate rolling process of AZ31 magnesium alloy can be accurately simulated by establishing a multi-scale macro and micro simulation model.This work provides a new idea for accurate control of high strain rate rolling of magnesium alloy.