Polycrystalline cubic boron nitride composite material containing rod crystal structure as well as preparation method and application of polycrystalline cubic boron nitride composite material

The invention provides a polycrystalline cubic boron nitride composite material containing a rod crystal structure and a preparation method and application thereof, and belongs to the technical field of superhard composite materials, the polycrystalline cubic boron nitride composite material is prepared from the following raw materials by mass: 45-90% of cubic boron nitride, 9-50% of a binder, 1-5% of a sintering aid and 0.5-2% of a rare earth oxide. The bonding agent is added, so that the cubic boron nitride and the bonding agent generate a new phase containing a rod crystal structure in the sintering process, the cubic boron nitride is firmly bonded, the compatibility between the cubic boron nitride and a polycrystalline cubic boron nitride matrix is good, the interface bonding strength is high, and therefore the bending strength of the polycrystalline cubic boron nitride is improved. The result of the embodiment shows that the bending strength of the polycrystalline cubic boron nitride composite material c