Development of high strength reaction-sintered silicon carbide

In reaction-sintered silicon carbides, usually 10-40 vol% of the residual silicon phase remains after the reaction-sintered process. For this reason, the bending strength of reaction-sintered silicon carbides decreases to or below 300 MPa. The raw material composition (C/SiC) and the starting particle size were optimized in order to decrease the volume fraction of residual silicon and the SiC grain size. There was a tendency for the strength to increase with decreasing the residual silicon size. The strengthening effect may be attributed to the reduced residual silicon size. A reaction-sintered silicon carbide with a high bending strength of 1000 MPa could be developed by the present optimization method.