High-Temperature Toughening Mechanism in SiC/TiC Composites

Abstract

The characteristic low brittle-ductile transition temperature of TiC was utilized to toughen SiC matrix composites at high temperatures. AlN, Ti and C powders were used as a dopant to alter the intrinsic properties of SiC matrix or dispersed TiC particles. The fracture toughness of the SiC matrix was improved in the temperature from room temperature to 1600°C by the incorporation of dispersed TiC particles. At low temperatures, the toughening mechanism in SiC/TiC composites was crack deflection or crack bridging while above 1200°C, it was plastic deformation of TiC particles.