Introduction of Technology and Performance Characteristics of PCBN Tool

(1) High hardness and wear resistance. The hardness of PCBN is 3000-5000HV. The wear resistance of PCBN is about 50 times of that of cemented carbide tool, 30 times of that of coated cemented carbide tool and 25 times of that of ceramic tool. PCBN material is especially suitable for high hardness materials that can only be grinded before processing. It can not only get better surface quality of workpiece, but also realize "replacing grinding by turning", thus simplifying the processing technology and improving production efficiency.

(2) High thermal stability. The hardness of PCBN is higher than that of ceramics and cemented carbides at 800 ℃, so PCBN tools can be used to cut hardened steel and other high hardness materials at a speed of 3-5 times higher than that of cemented carbide tools.

(3) Excellent chemical stability. PCBN is chemically inert and stable to acids and bases in reducing gas medium. In the atmosphere and water vapor, there is no change and stability below 900 ℃, no chemical reaction with iron-based materials at 1200-13000 ℃, and only reaction with carbon at 2000 ℃. Therefore, PCBN tool can be competent for cutting hardened steel parts and chilled cast iron, and can cut cast iron materials at high speed.

(4) It has good thermal conductivity. The thermal conductivity of PCBN is second only to that of diamond in all kinds of tool materials. Therefore, the high thermal conductivity of PCBN tool can reduce the temperature at the tool tip, reduce the chemical wear of the tool and improve the machining accuracy. It has lower friction coefficient. The friction coefficient between PCBN and different materials is about 0.1-0.3, which is much smaller than that of cemented carbide. The friction coefficient decreases with the increase of cutting speed. Low friction coefficient can reduce the cutting force, reduce the cutting temperature and improve the quality of the machined surface.