Effect of template content on microstructure and flexural strength of porous mullite-bonded silicon carbide ceramics

Abstract

Porous mullite-bonded SiC (MBSC) ceramics were fabricated at temperatures ranging from 1400 to 1500°C for 2 h using silicon carbide (SiC), alumina (Al2O3), strontium oxide (SrO), and poly (methyl methacrylate-coethylene glycol dimethacrylate) (PMMA) microbeads. The effect of template content on porosity, pore morphology, and flexural strength were investigated. The porosity increased with increasing the template content at the same sintering temperature. The flexural strength showed maximum after sintering at 1450°C/2 h for all specimens due to small pores and dense strut. By controlling the template content and sintering temperature, it was possible to produce porous MBSC ceramics with porosities ranging from 30% to 54%. A maximum flexural strength of-51 MPa was obtained at 30% porosity when no template were used and specimens sintered at 1450°C/2h.