蓝宝石晶体吸收系数对晶体内温度及热应力分布的影响

Effect of Absorption Coefficient of Sapphire on Temperature and Thermal Stress Distributions in Crystal Grown by Heat Exchanger Method

针对工业用热交换法蓝宝石晶体生长炉,建立了二维全局传热数值模型,采用离散坐标辐射模型对晶体内辐射传热进行了模化,研究了晶体吸收系数对晶体内部温度及热应力分布的影响规律。研究表明:在内辐射的作用下,大的轴向温度梯度及热应力区域集中在晶体底部1 cm的范围内,并且随着吸收系数(1.9~1 900 m^(–1))增大,晶体底部的最大轴向温度梯度及热应力呈现先增大后减少的趋势。

For an industrial-scale sapphire furnace of heat exchanger method, a two-dimensional global model of heat transfer was established. The internal radiation heat transfer of crystal was simulated by discrete ordinate method. The effect of absorption coefficient on the temperature and thermal stress distributions in the sapphire crystal was investigated. The numerical results indicate that under the effect of the internal radiation, the region with great axial temperature gradient and thermal stress is located at the bottom of the crystal in a range of 1 cm from the bottom surface of the crystal. The maximal axial temperature gradient and stress firstly increase and then decrease with the increase of the crystal absorption coefficient froml.9 m^（-1） to 1 900 m^（-1）.