Toughening of SiC with Ti 3 SiC 2 Particles

Composites in the SiC–TiC–Ti 3 SiC 2 system were synthesized using reactive hot pressing at 1600°C. The results indicate that addition of Ti 3 SiC 2 to SiC leads to improved fracture toughness. In addition, high microhardness can be retained if TiC is added to the material. The best combination of properties obtained in this study is K I c =8.3 MPa·m 1/2 and H v =17.6 GPa. The composition can be tailored in situ using the decomposition of Ti 3 SiC 2 . Ti 3 SiC 2 decomposed rapidly at temperatures above 1800°C, but the decomposition could be conducted in a controlled manner at 1750°C. This can be used for synthesis of fully dense composites with improved properties by first consolidating to full density a softer Ti 3 SiC 2 ‐rich initial composition, and then using controlled decomposition of Ti 3 SiC 2 to achieve the desired combination of microhardness and fracture toughness.