Al-Si合金枝晶形貌的三维相场模拟

Three-dimensional phase field simulation of dendritic morphology of Al-Si alloy

摘要:

基于包含固相扩散系数的Karma薄界面相场模型,采用三维自适应网格划分法,研究了界面宽度、热噪声幅值对Al-Si合金过冷熔体中枝晶生长行为的影响。模拟结果表明：随着界面宽度的增加,枝晶形貌的复杂度下降,枝晶尖端速度下降,尖端液相处溶质的富集程度下降；随着热噪声幅值的增加,枝晶尖端变化较小,位于枝晶主干两侧的二次枝晶的数量和不对称度增加。

Abstract:

Based on the Karma thin interface phase-field model which include the solid diffusivity, the effects of interface width and thermal noise on the dendrite growth behavior in undercooled melt of Al-Si alloy were studied by using three-dimensional adaptive meshing method. The simulation results show that with the increase of interface width, the complexity of dendrite morphology decreases, the dendritic tip velocity decreases and the solute concentration at the tip liquid phase decreases. With the increase of thermal noise amplitude, the dendritic tip changes small, the number and asymmetry of secondary dendrites located on both sides of the dendrite increases.