Microstructure formation of porous silicon carbide ceramics during β-α phase transformation

Abstract

The effect of particle size and initial powder phase on the microstructure of porous SiC ceramics was investigated. When β-SiC powder was used as a starting material, porous SiC ceramics were formed by rapid grain growth of α-SiC during the β-α phase transformation. As the particle size of the initial powders decreased, β-α SiC phase transformation and rapid grain growth of α-SiC occurred earlier. Grain and pore size of SiC porous ceramics can be controlled by the addition of α-SiC seed. Grain and pore size decreased as the concentration of α-SiC seed increased. The bending strength of porous SiC ceramics did not depend on pore size.