液相烧结SiC陶瓷

采用Al2O3、Y2O3为助烧剂，热压烧结获得了致密的α-SiC和β-SiC陶瓷，研究了起始粉末的性能对烧结体的物相组成和显微结构的影响。实验结果表明，Al2O3、Y2O3原位形成了YAG，材料以液相烧结机制致密化、并通过溶解和再析出机制，促进晶体生长。物相分析表明，β-SiC陶瓷粉末在烧结过程中发生了β→α的相变。显微结构观察显示，β-SiC陶瓷中生成了长柱状晶粒。

Microstructure Study on Liquid Phase Sintered SiC

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.