Effects of Mo 2 C 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·m1/2, 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. [ABSTRACT FROM AUTHOR]