Boron carbide-tungsten carbide composite ceramic gradient material for tool as well as preparation method and application of boron carbide-tungsten carbide composite ceramic gradient material

The invention belongs to the technical field of cutting tools, and discloses a boron carbide-tungsten carbide composite ceramic gradient material for a tool and a preparation method and application ofthe boron carbide-tungsten carbide composite ceramic gradient material. The surface layer of the ceramic gradient material comprises 70-100 vol% of B4C and 0-5 vol% of Co, wherein the core part of the ceramic gradient material contains 50-95 vol% of WC and 5-20 vol% of Co; the relative density of the material is higher than 97%, the hardness of the surface layer is 20-35 GPa, and the fracture toughness of the surface layer is 3-10 MPa.m < 1/2 >. The hardness of the core part is 14-22 GPa, and the fracture toughness of the core part is 8-20 MPa.m < 1/2 >. By controlling the contents of boron carbide, tungsten carbide and metal cobalt on the surface and the core, the hard-surface tough-core high-performance boron carbide-tungsten carbide composite ceramic gradient material is prepared by hot pressed sintering. The