Characteristics of PCBN Cutting Tools

PCBN cutting tool is made of CBN grains by high temperature and high pressure sintering with or without binder. Its structure is composed of integral sintering type and composite sheet with cemented carbide matrix. Because PCBN is mainly made of CBN, PCBN cutting tool has all kinds of excellent properties of CBN. Its main characteristics are as follows:

• High strength and wear resistance

The crystal structure of polycrystalline cubic boron nitride is similar to that of diamond, and its hardness and compressive strength are close to that of diamond. In cutting with PCBN cutting tool, its wear resistance is much higher than that of cemented carbide cutting tools, and can be used for machining tough cast iron and steel or other alloy materials with high strength, high hardness and high thermal sensitivity.

• Excellent chemical stability

CBN has high chemical stability and will not react with iron materials when the temperature reaches 1200-1300 ℃, and CBN will not be oxidized at 1000 °C, so the chemical wear of PCBN cutting tools is smaller than that of other tool materials in cutting.

• Good thermal conductivity and low friction coefficient

The thermal conductivity of CBN is much higher than that of high speed steel, vitrified and cemented carbide, and the thermal conductivity of PCBN cutting tools increases with the increase of temperature. This makes the temperature of cutting tip not too high in cutting, which is beneficial to improve the tool durability and prolong the service life of the tool. When CBN interacts with other materials, the friction coefficient is about 0.1-0.3, which is much smaller than that (0.4-0.6) between cemented carbide and other materials, so that the cutting force and cutting temperature are reduced, the tool sticking phenomenon is reduced in cutting, the chip accumulation is effectively avoided, and the surface machining quality of the workpiece is improved.