元胞自动机法模拟Al-Cu单相合金凝固组织

Microstructure simulation of single-phase Al-Cu alloy during solidification using cellular automaton method

改进模拟枝晶生长常用的二维元胞自动机模型,根据Al-Cu二元合金相图,拟合出固液分配系数和液相线斜率随温度变化的曲线方程,并将其耦合入改进的模型中。应用该模型模拟出金属凝固过程中单个、多个枝晶的生长形貌和溶质浓度分布,将模拟结果与固液分配系数和液相线斜率恒定时得到的结果进行对比分析。结果表明,改进后的模型实现了枝晶生长过程中固液相溶质浓度的分离,耦合曲线方程后模拟得到的溶质浓度分布更加均匀平滑,更符合凝固基本理论。

Based on the usual binary cellular automaton method, a modified cellular automaton model was established to simulate the growth of dendrite. According to the Al- Cu binary alloy phase diagram, the curve equation of solid-liquid distribution coefficient and liquidus slope with temperature was confirmed, and was coupled to the new model. The dendritic growth process and the distribution of solute concentration during the solidification were simulated. The simulated results were compared with the results while the solid-liquid distribution coefficient and the liquidus slope keep constant. The results show that the new model can realize the separation of solute concentration of solid and liquid phase in dendrite growth processes, so the distribution of solute concentration becomes smoother after coupling the curve equation, and agrees well with the basic theory of solidification.