Effect of Carbon Source on Porosity and Flexural Strength of Porous Self-Bonded Silicon Carbide Ceramics

Porous self-bonded silicon carbide (SBSC) ceramics were fabricated at temperatures ranging from 1700 to 1850 degrees C using SiC, silicon (Si), and three different carbon (C) sources, including carbon black, phenol resin, and xylene. The effects of the Si:C ratio and carbon source on porosity and strength were investigated as a function of sintering temperature. Porous SBSC ceramics fabricated from phenol resin showed higher porosity than the others. In contrast, porous SBSC ceramics fabricated from carbon black showed better strength than the others. Regardless of the carbon source, the porosity increased with decreasing the Si: C ratio whereas the strength increased with increasing the Si:C ratio.