基于L-J位错密度模型的7050铝合金微观组织演变模拟

Simulation of microstructure evolution of 7050 aluminum alloy based on L-J dislocation density model

为了模拟分析铝合金热变形过程中的微观组织演变过程,采用热物理模拟试验机对7050铝合金在变形温度分别为573、623、673和723 K和应变速率分别为0.01、0.1、1和10 s^(-1)的条件下进行了热压缩试验。通过对试验数据进行处理,求解得到了7050铝合金的动态软化系数与加工硬化系数,并建立了改进后的Laasraoui-Jonas(L-J)临界位错密度模型,将该模型应用于合金热压缩变形过程的微观组织模拟,并与试验结果进行对比。结果表明:采用修正的L-J位错密度模型可以计算7050铝合金动态再结晶过程中的位错密度;修正的L-J位错密度模型结合元胞自动机能比较精确地模拟7050铝合金的动态再结晶过程。

In order to simulate and analyze the microstructure evolution of aluminum alloy during hot deformation,the hot compression tests of 7050 aluminum alloy were carried out on a Gleeble-3500 thermo-physical simulation testing machine under the conditions of deformation temperatures of 573 K,623 K,673 K and 723 K and strain rates of 0.01 s^(-1),0.1 s^(-1),1 s^(-1) and 10 s^(-1),respectively.By analyzing the experimental data,the dynamic softening coefficient and work hardening coefficient of the 7050 aluminum alloy were obtained,and the modified Laasraoui-Jonas(L-J)critical dislocation density model was established.The model was applied to the microstructure simulation of the alloy during hot compression deformation,and compared with the experimental results.The results show that the dislocation density during dynamic recrystallization of the 7050 aluminum alloy can be calculated by using the modified L-J dislocation density model,and the modified L-J dislocation density model combined with cellular automata can accurately simulate the dynamic recrystallization process of the 7050 aluminum alloy.