垂直Bridgman法生长氟化钙晶体的数值分析

利用Fluent软件,模拟计算了垂直Bridgman法大尺寸氟化钙晶体生长的具体过程,研究了晶体生长过程中的热传递和熔体对流传热,分析了固相、液相和坩埚的热导率的差异对坩埚中心轴的轴向温度分布和轴向温度梯度以及界面处的径向温度分布和径向温度梯度的影响。分析结果表明:熔体对流传热的效果随晶体生长的不断进行逐渐减弱;固相、液相和坩埚的热导率的差异对坩埚中心轴的轴向温度分布和轴向温度梯度以及界面处的径向温度分布和径向温度梯度有重要影响;晶体的结晶速度和坩埚的下降速度存在不一致性。

Numerical simulation of calcium fluoride crystals growth by the VB method

With Fluent software, specific growth process of large size calcium fluoride crystals by the vertical Bridgman method was simulated and calculated. The heat transfer and the melt convection of crystal growth process were investigated. The difference of the thermal conductivity of solid phase, liquid phase and crucible has effect on axial temperature profile and axial temperature gradient profile along the centerline of the crucible and radial temperature profile and radial temperature gradient profile at the solid-liquid interface was analyzed. The results show that the effect of the melt convection heat transfer becomes weak with continuous crystal growth;The difference of the thermal conductivity of solid phase, liquid phase and crucible has important effect on axial temperature profile and axial temperature gradient profile along the centerline of the crucible and radial temperature profile and radial temperature gradient profile at the solid-liquid interface;Rate of crystallization are inconsistent with descent velocity of crucible.