IN-SITU SYNTHESIZED TIB2 TOUGHENED SIC

A new process of preparing SiC-TiB2 particulate-reinforced composite b y in-situ synthesis has been developed TiB2 particles were formed in s itu by chemical reaction between TiH2, Si and B4C; the particle size o f the TiB2 is usually about 2 mu m. The composite containing 30 vol% T iB2 exhibited a facture toughness of 6.21 MPa m(1/2) and a flexural st rength of 400 MPa. It was suggested that the main toughening mechanism s are the thermal residual stress field, crack bridging by TiB2 partic les and crack deflection around TiB2 particles.