相场法模拟AZ31镁合金再结晶晶粒长大

Simulation of grain growth of AZ31Mg alloy during recrystallization by phase field model

建立一个相场模型,并对AZ31镁合金进行再结晶晶粒长大模拟,提出一系列法则以确定模型中参数的真实值,从而实现组织演化在工业应用范围内的-真实时空模拟。在300～400℃100min内时,模拟结果与实验结果吻合得很好,在250℃时,模拟结果与实验结果有较大偏离,说明该合金体系的界面迁移激活能在低温时有所改变,定量模拟研究该合金组织的混晶程度。结果表明:合金在300～400℃时,随时效时间的延长,混晶特别严重。模型模拟相场法界面控制过程组织演变的真实时空,所确定的参数值也可以用于其他相似合金系统的模拟。

A model was established to simulate the realistic spatio-temporal microstructure evolution in recrystallization of Mg alloy using the phase field approach.The rules were proposed to decide the real physical values of all parameters in the model.The simulated results agree well with the reported experimental measurements at 300-400 ℃ in 100 min.However, there is an obvious deviation between the simulation and experimental results at 250 ℃, which indicates a variation in interface mobility activation energy of the alloy system at the temperature.The grain size fluctuation in the microstructure was studied quantitatively.The results show that the grain size becomes more severe with increasing aging time at the temperatures of 300-400 ℃.The model simulates the grain growth in real spatio-temporal scale for the first time and the parameter values can be regarded as a database for other similar alloy systems.