Temperature Field Design, Process Analysis and Control of Sapphire Crystals by SAPMAC Method

The transparent sapphire crystal of 240mm in diameter, 210mm in length and 27.5kg in weight was grown successfully along a axis by the SAPMAC method. The relationship between temperature field distribution, growing speed, cooling rate and the density of defects, crack of crystal was discussed theoretically. The optimized temperature field distribution and process control to grow large scale crystals by the SAPMAC method were designed. Large scale sapphire rod and plank window were manufactured with special equipments. The infrared transmittance property of a standard specimen was measured as well.