Superhard tool materials refer to synthetic diamond and CBN (cubic boron nitride), which have similar hardness and performance to natural diamond. Since natural diamond is relatively expensive, artificial polycrystalline diamond (PCD), polycrystalline cubic boron nitride (PCBN), and their composite materials are mostly used in production.

　　Superhard tool materials have the characteristics of high efficiency, long service life and good processing quality. In the past, they were mainly used for finishing. In recent years, due to the improvement of the production process of artificial superhard tool materials, the purity and grain size of In addition to composite materials and hot pressing technology, the scope of application continues to expand. In addition to being suitable for general finishing and semi-finishing, it can also be used for roughing. It is recognized as one of the promising tool materials for improving productivity in contemporary times. Using superhard materials to process parts such as steel, cast iron, non-ferrous metals and their alloys, the cutting speed can be an order of magnitude higher than that of cemented carbide, and the tool life can be dozens or even hundreds of times higher than that of cemented carbide. At the same time, its appearance has also changed the traditional process concept. The use of superhard tools can often directly replace grinding (or polishing) with turning and milling. For hardened parts, a single process can be used to replace multiple processes, which greatly shortens the process flow. .

　　Diamond has been used in cutting processing for hundreds of years as a superhard tool material. Tool development process, from the end of the nineteenth century to the beginning of the twentieth century, high-speed steel is the main representative of tool materials; in 1927, Germany first developed cemented carbide tool materials and was widely used; in the 1950s, Sweden and the United States were synthesized separately The artificial diamond was produced, and the cutting tool entered the period of superhard materials. In the 1970s, people used high pressure to synthesize polycrystalline diamond (PCD), which solved the problem of scarcity and high price of natural diamonds, and widened the application of diamond tools to aviation, aerospace, automobiles, electronics, stone and other fields. .

　　PCD tool has extremely high hardness, good wear resistance, high processing efficiency, low friction coefficient and superior thermal conductivity. It is mainly used for processing aluminum alloy, copper alloy and other non-ferrous metals and woodworking materials, hard non-metallic materials, etc.