Spark plasma sintering of TiC-based composites toughened by submicron SiC particles

TiC-based composites toughened by submicron SiC particles with improved fracture toughness were fabricated and fracture mechanism has been investigated. It has been found that the improvement in fracture toughness of TiC–SiC composites is due to both crack paths propagating through uniformly distributed SiC particles and the fracture mode transition from intergranular type to transgranular type caused by the change of residual stresses originating from the addition of SiC particles. The optimum of fracture toughness (5.2 MPa m1/2) was achieved at 14.6 vol% SiC, whereas the toughness decreased with increasing amount of SiC beyond 30 vol%.