Natural diamond is a uniform crystal structure without internal grain boundaries, which makes the cutting edge of the tool theoretically reach atomic-level straightness and sharpness, strong

cutting ability, high precision and low cutting force. The hardness, wear resistance, corrosion resistance and chemical stability of natural diamond ensure the ultra-long life of the tool, can ensure continuous and long-term normal cutting, and reduce the impact of tool wear on the precision of the processed parts. Its high thermal conductivity can reduce the cutting temperature and thermal deformation of the parts. The excellent properties of natural large single crystal diamond can meet most of the requirements of precision and ultra-precision cutting for tool materials. Although it is expensive, it is still recognized as an ideal precision and ultra-precision tool material. It can be widely used in the processing of various reflectors in nuclear reactors and other high-tech fields, navigation gyroscopes in missiles and rockets, computer hard disk substrates, ultra-precision processing of accelerator electron guns, as well as traditional watch parts, jewelry, pen making, precision processing of metal-clad decorative parts, etc. In addition, it can also be used to manufacture medical tools such as ophthalmology, brain surgery scalpels, ultra-thin biological blades, etc. The current development of high temperature and high pressure technology makes it possible to prepare large single crystal diamonds of a certain size. The advantage of this diamond tool material is that its size, shape and performance are all consistent, which is not possible with natural diamond products. Due to the scarcity and high price of large-sized natural diamonds, the application of artificial large-grained single-crystal diamond tool materials as a substitute for natural large single-crystal diamonds in ultra-precision cutting will surely develop rapidly.