Host: The Ceramic Society of Japan
Precursors for silicon carbide powders were prepared from liquid mixtures of nano-micro carbon particles (carbon blacks, charcoal or powder diamond), phenolic resin and ethyl silicate. After the geletion, drying and pyrolysis at 1273K, carbon-silica hybrids were obtained with C/SiO2 ratios of ca. 3. In these materials, a part of carbon existed as nano-micro carbon particles dispersed in matrix. The other carbon, originated from phenolic resin, was located in the surrounding matrix area. These carbon-silica hybrids were heat-treated at 1838K in an Ar gas flow to obtain SiC powders with carbothermic reduction process. Conversion process of the hybrids to SiC was monitored by thermo gravimetric analysis. Influence of the state of the embedded carbon particles on conversion rates and resulting SiC particle morphology were investigated.
