Effects of Mo2C on Microstructures and Comprehensive Properties of Ti(C, N)-Based Cermets Prepared Using Spark Plasma Sintering

Ti(C, N)-based cermets are problematic in practical production applications due to their brittleness. To improve this defect, Ti(C, N)-based cermets were prepared under different sintering environments using a spark plasma sintering (SPS) device with different contents of Mo₂C and 25 wt.% of nano tungsten carbide as additives. By means of microstructural analysis and comprehensive performance tests, the Ti(C, N) cermet with 6 wt.% Mo₂C content showed the best comprehensive performance when sintered at 1450 °C under a pressure of 25 MPa with a holding time of 16 min. The density of this metal-ceramic was 6.27 g/cm³, the Vickers hardness was HV 2731, and the fracture toughness was 10.1 MPa·m^1/2, which increased the density by 15%, the hardness by 63%, and the fracture toughness by 84% compared with the ceramic without added Mo₂C. Densification of cermets can be promoted using SPS. The moderate addition of Mo₂C can improve the wettability between the bonded phase and the hard phase, and its joint action with tungsten carbide can promote the formation of a ring structure and inhibit the growth of core-structure grains to enhance the toughness of the ceramic.