相场法模拟Zn-Al二元合金凝固过程中的枝晶生长

建立了与温度场和溶质场相耦合的 Zn-Al 二元合金枝晶生长的相场模型，用相场法模拟了枝晶形貌及生长过程。通过分析得到的图像，研究了各向异性强度系数、界面动力学系数以及界面能对枝晶生长形貌和枝晶尖端生长速度的影响。结果表明：随着各向异性强度系数的增大，枝晶生长速率增加，且容易出现二次支臂。此外，界面动力学系数和界面能的增大也会不同程度地加速枝晶生长速率并对二次支臂的产生有着较为明显的促进作用。

Numerical Simulation of Dendrite Growth of Zn-Al Binary Alloy During Solidification Process Using Phase-field Method

A phase-field model coupling Zn-Al alloy dendrite growth to the temperature field and the solute field was established. The growing processes and morphologies of dendrite were simulated by using the phase-field method. Through analyzing the obtained images, the effects of anisotropic strength, interface kinetic coefficient and interfacial energy on dendrite morphology and growth rate of the dendrite tip were discussed. The results showed that with increasing anisotropic strength, the growth rate of the dendrite tip increased,and the secondary dendrite tended to appear. In addition, the increase of interface kinetics coefficient and interfacial energy also accelerated the growth of dendrite to various extent and stimulated conspicuously the generation of secondary dendrite.