基于KKS模型,采用相场和溶质场耦合的方法,对铝-铜二元合金的定向凝固过程进行了模拟.为了简化计算,采用了温度冻结近似;研究了各向异性、界面厚度、界面能等参数对界面形态和微观偏析的影响.结果表明:在各向同性的情况下,晶体生长为浅胞状枝晶生长;当引入各向异性后,随着各向异性系数的增大,晶体生长由浅胞状枝晶向深胞状枝晶转变;随着界面能和界面厚度的增加,胞晶间的凹坑变浅,晶体生长由深胞状枝晶向浅胞状枝晶转变.

The phase-field model based on KKS model which couples the solute field was used to simulate the process during directional solidification for Al-Cu binary alloy.Frozen temperature approximation was adopted to simplify the modeling.The effects of the parameters such as an isotropy coefficient,interface energy and interface thickness on interface morphology and micro-segregation were formulated.The results show that shallow cellular dendrite growth was the major growth pattern in isotropic circumstances.After introduction of the anisotropy,with the increase of the anisotropy coefficient the crystal growth transformed to deep cell from shallow cell.With the increase of interface energy and interface thickness,the crystal growth transformed to shallow cell from deep cell.