Polycrystalline Cubic Boron Nitride Material PCBN:
Polycrystalline Cubic Boron Nitride (PCBN) is a polycrystal formed by sintering cubic boron nitride (CBN) micropowder with a binder under high temperature and high pressure. The binders are mainly divided into two categories: metal type (such as Co, Ni) and ceramic type (such as TiC, TiN, Al₂O₃). The structure of cubic boron nitride (CBN) is similar to that of diamond, with the same type of chemical bond and similar lattice constant, so it has hardness and strength close to those of diamond.
The hardness of cubic boron nitride is second only to that of diamond, with a microhardness of 8000~9000HV. The hardness of polycrystalline cubic boron nitride PCBN is generally 3000-5000HV. When cutting wear-resistant materials, its wear resistance is 50 times that of cemented carbide tools, 30 times that of coated cemented carbide tools, and 25 times that of ceramic tools. Due to PCBN's good chemical corrosion resistance and excellent thermal stability and red hardness at high temperatures, the relative high temperature at the tool tip will not have any adverse effect on it; on the contrary, it can accelerate the cutting process when cutting materials such as hardened steel and cemented carbide.
PCBN tools have higher impact strength and fracture resistance than ceramic tools, and are usually used to process various ferrous metal materials such as cast iron and hardened steel. In addition, some specially made PCBN tools can withstand the cutting load of high-power rough machining, the impact of interrupted cutting, as well as the wear and cutting heat during finishing.
In recent years, with the rapid development of CNC (Computer Numerical Control) machining technology and the widespread use of CNC machine tools, the application of PCBN tools, which can achieve high-efficiency, high-stability, and long-life machining, has become increasingly popular. At the same time, many advanced cutting concepts have been introduced, such as high-speed cutting, hard machining, turning instead of grinding, and dry cutting. PCBN tool material has become an indispensable tool material in modern cutting processing.