摘要
针对泡生法蓝宝石单晶生长的不同生长阶段的温场、流场和固液界面形状进行数值模拟研究。并分析了加热器相对坩埚的轴向位置和不同生长速率对蓝宝石单晶生长的影响。结果表明:在蓝宝石单晶生长中,在靠近坩埚壁面和固液界面的熔体内,等温线密,温度梯度较大;在靠近坩埚底部的熔体内,等温线稀疏,温度梯度较小。随着晶体高度的增加,熔体对流由放肩阶段的两个涡胞变成等径阶段的一个涡胞,熔体平均温度有小幅度下降;加热器相对坩埚的轴向位置对晶体生长炉内温场和固液界面形状影响很大,随着加热器位置上移,晶体内平均温度升高,温度梯度减小;熔体内平均温度降低,温度梯度增大。同时固液界面凸度增大。随着晶体生长速率增大,固液界面凸度增大,界面更加凸向熔体。
The growth process of sapphire crystal grown by Kyropoulos method were studied by numerical simulation, with emphasis on the temperature and flow fields and solid-liquid interface shape at different growth stages. The influences of heater relative axial position to the crucible and the growth rate were also investigated. Results show that during the sapphire crystal growth, the melt isotherms are dense and the melt temperature gradients are larger near the crucible wall and the solid-liquid interface; the melt isotherms are relatively sparse near the crucible bottom and the temperature gradient is lower. With the increase of crystal height, the melt convection changes from two vortexes at the shoulder stage into one vortex at equal diameter stage; the average melt temperature decreases slightly. The heater axial position relative to the crucible has great influence to the temperature field and solid-liquid interface shape. With the heater central position moves up relative to the crucible, the average crystal temperature increases, and the temperature gradient decreases; the average melt temperature decreases and the temperature gradient increases. At the same time, the convexity of solid-liquid interface increases. With the crystal growth rate increasing, the convexity of solid-liquid interface increases, and the interface is more convex toward the melt.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
2015年第10期2898-2902,共5页
Journal of Synthetic Crystals
基金
江苏高校品牌专业建设工程资助项目(PPZY2015C252)
关键词
蓝宝石
泡生法
数值模拟
固液界面
sapphire
Kyropoulos
numerical simulation
solid-liquid interface
