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

The effect of particle size and initial powder phase on the microstructure of porous SiC ceramics was investigated. When beta-SiC powder was used as a starting material, porous SiC ceramics were formed by rapid grain growth of alpha-SiC during the beta-alpha phase transformation. As the particle size of the initial powders decreased, (beta-alpha SiC phase transformation and rapid grain growth of alpha-SiC occurred earlier. Grain and pore size of SiC porous ceramics can be controlled by the addition of alpha-SiC seed. Grain and pore size decreased as the concentration of alpha-SiC seed increased. The bending strength of porous SiC ceramics did not depend on pore size. (C) 2016 Elsevier Ltd. All rights reserved.