关键词: 液相烧结;SiC;显微结构

Abstract: α-SiC ceramics and β-SiC ceramics were obtained by hot-pressing through using Al2O3 and Y2O3 as sintering additives.The effects of starting powder on the phase composition and microstructure of the sintered SiC were investigated.The materials were densified based on liquid phase sintering mechanism,in which YAG was formed in situ by the reaction of Al2O3 and Y2O3.The relatively large grains showed that the grain grew through solution-reprecipitation.The phase analysis revealed that the phase transformation of β→α in β-SiC ceramics occurred during sintering.The morphology indicated that the rod-like grains are formed in the β-SiC ceramics.