▎ 摘　　要

NOVELTY - A high-strength boron nitride ceramic composite material is prepared by using high-purity hexagonal boron nitride powder as raw material, adding titanium carbide whiskers, silicon carbide whiskers and 10 wt.% sintering aid boron trioxide, stirring under ultrasonic environment, adding 5 wt.% chromium and 0.2 wt.% graphene, stirring under ultrasonic condition, adding the raw material into the ball milling tank, using absolute ethanol as ball milling medium, adding zirconia grinding balls where material-to-ball ratio is 1:10, ball milling for 20 hours, drying in a drying cabinet for 12 hours, grinding and sieving to obtain a uniform composite powder, feeding into sintering furnace, filling nitrogen gas during the sintering process for protection, and leaving still at the highest sintering temperature for 1 hour. The purity of boron nitride fine powder is greater than 99%. The purity of the sintering aid boron trioxide powder with an average particle size of 1 mu m is greater than 98%. USE - High-strength boron nitride ceramic composite material. ADVANTAGE - The high-strength boron nitride ceramic composite material is prepared at lower sintering temperature about 1300-1500 degrees C. The density and bending strength of boron nitride ceramic composites are increased when increasing the sintering temperature and sintering pressure. The titanium carbide whiskers and silicon carbide whiskers in ceramic composite material have high strength and elastic modulus. The chromium has high strength, excellent toughness and corrosion resistance, which can improve the hardness and fracture resistance of the ceramic composite material. The graphene has extremely high strength and excellent toughness, which can improve the bending resistance of the material, and extend the service life of the ceramic composite material. DETAILED DESCRIPTION - A high-strength boron nitride ceramic composite material is prepared by using high-purity hexagonal boron nitride powder as raw material, adding titanium carbide whiskers, silicon carbide whiskers and 10 wt.% sintering aid boron trioxide, stirring under ultrasonic environment, adding 5 wt.% chromium and 0.2 wt.% graphene, stirring under ultrasonic condition, adding the raw material into the ball milling tank, using absolute ethanol as ball milling medium, adding zirconia grinding balls where material-to-ball ratio is 1:10, ball milling for 20 hours, drying in a drying cabinet for 12 hours, grinding and sieving to obtain a uniform composite powder, feeding into sintering furnace, filling nitrogen gas during the sintering process for protection, and leaving still at the highest sintering temperature for 1 hour. The purity of boron nitride fine powder is greater than 99%. The purity of the sintering aid boron trioxide powder with an average particle size of 1 mu m is greater than 98%. The content of titanium carbide whiskers and silicon carbide whiskers in boron nitride powder is 7-12%. In the sintering process, the nitrogen gas is filled at sintering temperature of 1300-1500 degrees C under a fixed sintering pressure, on other hand, nitrogen gas is filled at sintering pressure of 20-30 MPa under fixed sintering temperature.