Ultra-hard ceramic bulletproof piece and preparation method thereof

The invention relates to an ultra-hard ceramic bulletproof piece and a preparation method thereof. The ultra-hard ceramic bulletproof piece is excellent in bulletproof performance. The ultra-hard ceramic bulletproof piece is prepared from, by weight, 70%-92% of a main ceramic phase and 8%-30% of sintering agents. The main ceramic phase is one of cubic boron nitride and diamond or a mixture of cubic boron nitride and diamond. The preparation method includes the following steps that 1, the main ceramic phase and the sintering agents are mixed into composite powder according to the proportion; 2, the composite powder obtained in the step 1 is sintered for 8-25 min under the barometric pressure of 30,000-60,000 and the temperature of 1,200 DEG C-1,900 DEG C, after cubic boron nitride and/or diamond are/is compounded with any one of or the combination of graphene, carbon fibers, metal, compounds of the metal and rare earth oxides, sintering conditions become mild, the required sintering temperature ranges from 1,200 DEG C to 1,900 DEG C, and the sintering pressure ranges from 30,000 to 60,000. The obtained ceramic bulletproof piece has high rigidity, fracture toughness, bending strength and impact toughness.