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采用凝固相场模型,耦合了温度场和溶质场,模拟了Ni-40.83%Cu合金枝晶生长过程,并研究了界面原子运动时间参数对合金枝晶生长中的影响规律。研究表明:当原子运动系数较小时,固液界面不稳定,扰动容易被放大,枝晶生长速度加快,并容易产生二次枝晶,枝晶溶质扩散充分,晶界处形成较厚的溶质扩散层;随着界面原子运动系数的增加,固液界面变的稳定,容易形成光滑的枝晶,由于溶质扩散速度小于枝晶生长速度致使界面溶质扩散层变薄。
The solidification phase field model was used to simulate the dendrite growth of the Ni-40.83% Cu alloy by coupling the temperature field and the solute field. The influence of interface atomic movement time parameters on the dendrite growth was also studied. The results show that when the atomic coefficient of motion is small, the solid-liquid interface is unstable, the perturbation is easily amplified, the dendrite growth speed is accelerated, secondary dendrites are easily produced, the diffusion of solute in the dendrites is sufficient, and thick solute diffusion occurs in the grain boundaries Layer. As the movement coefficient of the interface increases, the solid-liquid interface becomes stable and a smooth dendrite is easily formed. As the diffusion speed of solute is smaller than the dendrite growth rate, the interface solute diffusion layer becomes thinner.