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利用相场模型与溶质场进行耦合计算,模拟了二元Ni-Cu合金等温凝固的枝晶生长过程,研究了扰动对枝晶生长及溶质场和相场分布的影响。结果表明:当扰动大小取值适当时,热噪声的引入能引发侧向分枝,但不改变枝晶尖端的稳态行为;扰动可促进二次晶臂生长,加扰动后初生枝晶要长一些,即生长速度要快,枝晶形貌也更加复杂;随着扰动幅值的增大,枝晶尖端分叉程度增大;在枝晶生长过程中,枝晶尖端的浓度梯度最大,另外在被二次晶臂包围的界面区域,溶质浓度最高。
The phase transition model and the solute field were used to simulate the growth of dendrite grown by isothermal calcination of binary Ni-Cu alloy. The effects of the perturbation on the dendrite growth and the distribution of solute field and phase field were studied. The results show that the introduction of thermal noise can lead to lateral branching when the perturbation value is appropriate, but it does not change the steady-state behavior of the dendrite tip. The perturbation can promote the growth of the secondary crystal arm. Some, that is, faster growth, dendritic morphology is more complex; with the disturbance amplitude increases, dendrite tip bifurcation degree increases; dendrite growth process, the dendrite tip concentration gradient maximum, the other The solute concentration is the highest in the interface area surrounded by the secondary crystal arm.