SAPMAC法生长大尺寸蓝宝石晶体的碎裂分析  

Crack during the Growth of Large Scale Sapphire by SAPMAC Method Process

作　　者：许承海[1] 孟松鹤[1] 韩杰才[1] 张明福[1] 左洪波[1] 

机构地区：[1]哈尔滨工业大学复合材料与结构研究所,哈尔滨150001

出　　处：《硅酸盐通报》2009年第B08期186-189,共4页Bulletin of the Chinese Ceramic Society

摘　　要：在SAPMAC法晶体生长过程中常常出现晶体开裂现象,导致试验失败;根据裂纹萌生的位置、扩展程度可将其概括为全开裂(粉碎性开裂)和体内开裂(节理面开裂)两种开裂形态。研究结果表明:引起晶体开裂的主要原因是晶体内部由温度分布不均匀所引起的热应力,晶体内热应力与系统温度梯度、晶体热膨胀系数及晶体直径成正比;过快的晶体生长速率和过快的冷却速率,将会引起晶体内部整体热应力过大,造成晶体整体碎裂;在晶体直径突变及包裹物边缘位置易产生应力集中,微裂纹在应力集中位置萌生,并沿薄弱的(11-20)或(01-12)面扩展,造成晶体局部开裂。本实验室通过设计合理而稳定的温场、优化晶体生长工艺及退火处理等方法,较好地解决了蓝宝石晶体的开裂问题,生长了直径达240mm的大尺寸蓝宝石晶体。Cracks during the growth of large-sized sapphire with SAPMAC method uaually leads to experiment failure. According to the germination region and propagation condition of cracks, it can be divided into two kinds： unitary and partial. As shown by result, crystal cracks took place duo to heat stress by the uneven distribution of temperature field. For the stress distribution of crystal, it is strongly dependent on the temperature gradient, growth rate, the coefficient of thermal expansion of crystal and diameter of crystal. High thermal stress in the crystal for excessively high growth speed and cooling rate leads to crystal failure. It causes stress concentration at the position that it changes sharply for diameter. Micro-cracks are likely to form at the region with stress concentration, and spread in the （11-20） planes and （01-12） planes, finally partial cracks. Temperature field of crystal growth by SAPMAC method was designed, and growth process of crystal was optimized. A good quality sapphire was successfully fabricated with diameter 240 mm.

关 键 词：热应力 晶体裂纹 蓝宝石 SAPMAC 

分 类 号：O781[理学—晶体学]