Al-Si合金枝晶生长相场法模拟影响因素

Influencing factors of Al-Si alloy dendritic growth simulation by phase-field method

采用相场法技术,确定了噪声、初始晶核半径、各向异性及过冷度等因素对枝晶生长形貌模拟的影响规律.结果表明:在保证初始晶核不被熔化的前提下,初始晶核半径r0的大小不影响模拟结果;随着界面各向异性系数的增大,枝晶尖端生长速度以线性方式增大,而枝晶尖端半径以抛物线方式减小;过冷度越小,枝晶的生长越困难,越不能出现二次枝晶.相场法模拟影响因素对枝晶生长形貌模拟有重要的影响.

The phase-field method was adopted to investigate the effects of noise, initial crystal nuelei＇s radius, anisotropy and super-cooling degree on the simulation of dendritic growth in Al-Si alloys. The results show that if the initial crystal nucleus is not melted, its size has nothing to do with the simulation results. With the coefficient of interfaeial anisotropic strength increasing, the dendritic tip＇s growing speed increases linearly, while its radius decreases parabolically. The lower the sub-cooling degree is, the more difficult it is to find secondary dendrites. As a result, the influencing factors in phase-field simulation have important impact on dendritic growth simulation.