The Advantages of PCBN and PCBN Cutting Tools

Polycrystalline cubic boron nitride (PCBN) is composed of CBN powder and a small amount of binding phase (Co, Ni or TiC, TiN, Al203), which is sintered together with catalyst under high temperature and high pressure. It has very high hardness (second only to diamond), heat resistance (1300 ~ 1500 ℃), excellent chemical stability, thermal stability (1400 ℃) and thermal conductivity than diamond cutting tool, low coefficient of friction, but its intensity is low.

Compared with diamond, PCBN has some prominent advantages: It has much higher thermal stability, up to 1200 ℃ (diamond at 700 ~ 800 ℃), and can withstand higher cutting speed; It has big chemical inertness, and has no chemical reaction with iron group metals under 1200 ~ 1300 ℃, which can be used for processing steel. Therefore, PCBN cutting tool is mainly used for efficient processing black difficult-to-machine materials.

Besides the characteristics of the above, PCBN cutting tool still has the following advantages:

A, It has high hardness, particularly suitable for processing hardened steel over HRC50, heat resistant alloy over HRC35 and grey cast iron and other tools under HRC30;

B, Compared with cemented carbide cutting tools, the cutting speed is high, and it can realize high efficient cutting;

C, It has good abrasion resistance, high tool life (10 to 100 times of cemented carbide cutting tools), and can obtain better surface quality of workpieces, instead of grinding. Its shortcoming is that PCBN cutting tool has poor shock resistanc, therefore, people should pay attention to improving the rigidity of process system when using, to avoid impact cutting.