Effect of WC Powder Size on the Microstructure and Properties of Ti（C,N）-based Cermets

Mo₂C is normally added to improve the wettability between Ti （C,N） and Ni in Ti （C,N）-based cermets. Due to the increasing price of Mo₂C,much attention has been paid to Ti （C,N）-based cermets with WC addition. In this paper,the effect of WC powder size on the microstructure and properties of Ti(C_0.7N_0.3)-15% WC-15% Ni cermets free of Mo₂C was studied. The experimental results show that the cermet with smaller size of WC powder addition presents a white core and grey rim structure,and the grains have smaller size （average grain size is below 2 μm） and a uniform size distribution. Furthermore,the ultra-fine WC powder can not only raise its own dissolution rate but also that of Ti （C,N）. Although the ultra-fine WC powder can increase the hardness of the cermet,it makes the fracture toughness of the cermet have a reduction.