摘要
通过调整复相陶瓷中颗粒相的组成与级配,利用引入的热膨胀失配机制,控制莫来石/刚玉复相陶瓷显微结构,改善高温复相陶瓷热稳定性,着重研究了莫来石/刚玉复相陶瓷的热断裂特性。研究表明,全部采用莫来石颗粒相时,由于柱状莫来石颗粒极易发生热冲击穿晶断裂,且热膨胀失配导致的微裂纹较长,密度较小,故复相陶瓷热稳定性较差;全部采用刚玉颗粒相时,虽然基质相裂纹扩展至刚玉颗粒表面时穿晶断裂与沿晶的裂纹扩展同时发生,有利于改善复相陶瓷热稳定性,但由于热膨胀失配过度,未经热冲击时已产生宏观裂纹,故热稳定性最差。而采用莫来石/刚玉复合颗粒相,相比例为对75/25制备的复相陶瓷试样,热膨胀失配形成的微裂纹较短,密度较大,其热稳定性最优。
Microstructure of mullite-corundum duplex ceramics were controlled through adjusting composition and
gradation of aggregates to introduce appropriate thermal mismatch in order to improve thermal shock resistance of the
mentioned ceramics. The results show that the sample made with only mullite aggregate appears relatively longer and fewer
micro-cracks due to thermal mismatch, together with easy fracture of mullite aggregate under the thermal shock, which
resulte in inferior thermal shock resistance. The sample made with only corundum aggregate shows the worst thermal shock
resistance due to over-mismatch and macro-cracks appeared before thermal shock. While the sample made with 75/25
of mullite/corundum composite aggregates appears shorter and denser micro-cracks due to thermal mismatch, which
result in excellent thermal shock resistance.
出处
《硅酸盐通报》
CAS
CSCD
2004年第5期32-35,共4页
Bulletin of the Chinese Ceramic Society
