Effect of Sintering Temperature and Particle Size on Porous SiC/Si<sub>3</sub>N<sub>4</sub> Composite Ceramics

Porous SiC/Si 3 N 4 composite ceramic was prepared at different temperatures by pressureless using SiC and Si 3 N 4 as raw materials. The effects of sintering temperature and different particle size of SiC on porosity SiC/Si 3 N 4 composite ceramic were investigated. The phases, microstructure and mechanical property were characterized by XRD, SEM, and compressive tests respectively. The results indicate that the increase of sintering temperature is in favor of the formation of β-Si 3 N 4 crystal phase, the porosity and the compression strengthof porous SiC/Si 3 N 4 composite ; The porosity of Si 3 N 4 /SiC block which contain particle graded higher than single particle size, but weaker compression strength.