Abstract:Ti(C, N)-WC-TaC-NbC-Co-Ni cermets were prepared by sintering in nitrogen atmosphere. The effects of sintering temperature and holding time on the microstructure and properties of the core and surface of Ti(C, N)-based cermets were studied. The results show that rimless-black-core and binder rich layer would be formed in Ti(C, N)-based cermets through a nitriding process. With the increase in sintering temperature, the equilibrium nitrogen decomposition pressure of the sample increased, the driving force of the nitriding process was weakened, and rimless-black-core and binder rich layer became thinner. With the extension of holding time, the rimless-black-core and binder rich layer on the surface became thicker, and the lack of black core on the subsurface layer became more and more obvious. With the increase of sintering temperature and the extension of holding time, the dissolution and re-precipitation were intensified, the volume fraction of Ti(C, N) black core decreased, the number of rim phase transformation and rimless black core decreased, and the grain size of hard phase increased. With the increase in sintering temperature, the hardness, cobalt magnetism and coercive magnetism of the alloy decreased gradually, while the fracture toughness increased first and then decreased. With the extension of holding time, the hardness and fracture toughness decreased first and then increased, while the cobalt magnetism and coercive magnetism increased gradually. The results show that the samples sintered at 1500 ℃ for 40 min had the best comprehensive properties, Vickers hardness reached 1544 HV30, fracture toughness was 9.0 MPa·m1/2, cobalt magnetic and coercive magnetic forces were 4.74 and 9.42 kA/m, respectively.