Effect of (Cr,La)₂(C,N) addition on the structure and properties of Ti(C,N)-based cermets

(Cr,La)₂(C,N) powders were prepared by the high temperature carbon tube furnace in an open system, using as the additive to prepare the Ti(C,N)-based cermets. The effects of (Cr,La)₂(C,N) on the microstructure and mechanical properties of the Ti(C,N)-based cermets were studied by X-ray diffraction (XRD), scanning electron microscope (SEM), universal mechanical testing machine, and Vickers hardness tester. The results show that the addition of (Cr,La)₂(C,N) can effectively refine the hard phase grains of the Ti(C,N)-based cermets. The Cr and La elements are mainly dissolved in the binder phase, and the La element promotes the dissolution and precipitation process of the hard phase. Furthermore, the bending strength, hardness, and fracture toughness of the cermets are significantly improved. When the mass fraction of (Cr,La)₂(C,N) is 5.0%, the comprehensive mechanical properties of the Ti(C,N)-based cermets are the best, the bending strength is 2002 MPa, the Vickers hardness is 1643 MPa, and the fracture toughness is 11.22 MPa·m^1/2.