REVERSE REACTION SINTERING OF Si3N4/SiC COMPOSITES

摘要

A method of making a composite sintered silicon nitride/silicon carbide body, including mixing a predetermined amount of silicon nitride powder with a predetermined amount of silicon carbide powder, heat-treating the resultant mixed powder at a temperature of between about 800 and 1500 degrees Celsius in a substantially nitrogen sintering atmosphere, and producing a thin film of silica around individual silicon nitride and silicon carbide grains. The thin film of silica is useful in retarding the diffusion of oxygen to the silicon nitride particles, slowing their oxidation. The pressure of the sintering atmosphere is not substantially greater than atmospheric pressure.