タイトルまたは説明

The superhard tool came into being due to the higher requirements of the processing of modern engineering materials in terms of hardness, and there was a great development in the last *0 years of the *0th century. The chemical composition and formation hardness of superhard materials are different from other tool materials. Cubic boron nitride is a non-metallic boride, and its crystal structure is face-centered cubic; while diamond is converted from carbon, and its crystal structure is the same as that of cubic nitrogen. Boronide is similar. Their hardness is much higher than other substances.