Effect of Ni-Mo Binder Content on Mechanical Properties of Spark Plasma Sintered TiC_0.7N_0.3-based Cermets

Taking TiC_0.7N_0.3, WC, C, Ni and Mo powder as raw materials, TiC_0.7N_0.3-based cermets with 0, 2wt%(Ni-Mo), 10wt%(Ni-Mo) binder were prepared by spark plasma sintering technology. The effect of binder content on the microstructure and mechanical properties of the cermets was studied. The results show that the TiC_0.7N_0.3-based cermets displayed a typical black core-gray ring structure. With increasing content of the Ni-Mo binder, the relative density of cermets increased, the proportion of core phase TiC_0.7N_0.3 decreased, the proportion of ring phase (Ti,W,Mo)(C,N) increased, the TiC_0.7N_0.3 particle size decreased, the fracture toughness increased, and the hardness increased first and then basically unchanged. The cermet with 10wt%(Ni-Mo) binder had excellent comprehensive mechanical properties with hardness of 17.14 GPa and fracture toughness of 6.76 MPa·m^1/2.