EFFECT OF THE SiC_W ON THE TOUGHENING BEHAVIOR OF TiB_2 / 25SiC_W CERAMIC COMPOSITE AT ELEVATED TEMPERATURE
SiCW对TiB2／25SiCW陶瓷材料高温增韧效果的影响

TiB2/25SiCw ceramic composite was fabricated by hot pressing technique.Substantial improvements in fracture toughness and bending strength were obtained for the composite compared with pure TiB2 ceramic.Considerable improvement in fracture toughness at elevated temperature of TiB2/25SiCwceramic composite was observed.It was found that the SiCw numbers that can be pulled out are much more increased as the temperature increased owing to the relaxation of the residual stresses caused by the thermal expansion mismatch.At low temperature,the whiskers are mainly fractured;but at elevated temperature,the whiskers are mainly pulled out.