高压热处理AlN陶瓷晶体的生长动力学

Growth kinetics of AlN ceramics crystal during high pressure annealing process

利用国产六面顶压机,对AlN（Y_2O_3）陶瓷进行了高压（5.0 GPa）热处理,对高压热处理AlN陶瓷的宏观动力学进行了研究。结果表明：超高压热处理时,温度越高、热处理时间越长,AlN晶粒粒径越大,晶体结构越完整。动力学分析表明,在热处理温度范围内（970～1210℃）,AlN晶体生长动力学指数为3,晶体生长激活能为（50.6±9.6）k J/mol。高压热处理时,AlN试样内部物质迁移的主要机制是压力强化的体积扩散。

AlN ceramics with additives of Y_2O_3 were annealed at high-pressure（ 5.0 GPa） in a domestic cubic anvil ultra high-pressure and high-temperature device.The crystal growth characteristic of the AlN ceramics and kinetics of the high-pressure heat treatment on AlN ceramics were studied.The results show that average particle diameter of the AlN crystal grains increases and crystal morphology becomes regular with the increase of annealing time and temperature.Kinetic analysis indicates that the kinetics index of crystal growth is 3 and the activation energy is（ 50.6 ± 9.6） k J / mol in the experimental temperature range（ 970-1210 ℃）.The dominant mechanism of matter migration is pressure-enhanced volume diffusion in the process of high pressure annealing.