铝合金定向凝固过程枝晶生长的相场法模拟

Phase-field simulations of dendritic growth in aluminum alloy directional solidification

摘要: 本文基于Wang等人提出的熵函数公式,在假定平衡时固液界面处固、液相的化学势相同而溶质浓度不同的基础上,推导了一个新的二元合金相场模型.并利用该相场模型与溶质场进行耦合计算,以Al-4.5%Cu合金为例模拟了二元合金等温凝固定向凝固的枝晶生长过程.研究了在正温度梯度情况下二元合金过冷熔体中的等轴枝晶和柱状晶的生长过程及其溶质场的分布情况..

Abstract: A new phase-field model is developed based on the entropy functional,proposed by Wang et al.The dendritic growth processes during isothermal directional solidifications in a Al-4.5%Cu binary alloy are simulated by using the phase-field model.Solute diffusion equation was solved simultaneously.The equiaxed and columnar dendritic growth,solute profile in undercooled liquid alloy are investigated under the positive temperature gradient.