With the rapid development and continuous progress of China's machinery, electronics, chemical and aerospace industry, these new super-hard cutting tools will be used in various fields more widely, and bring more benefits. This article concentrates on the elaboration of the performance characteristics and and applications of carbide cutting tools, PCD diamond tools, cubic boron nitride(CBN) cutters and silicon nitride ceramic inserts.
The hardness and weariness of CBN is second to diamond.It is a kind of polycrystalline synthesized from amber boron nitride at the same high temperature and pressure of synthetic diamond. It is heat resistant and chemically stable, and it can work normally at 1300 ~ 1500 ℃. There is no chemical reaction between CBN and most metals, iron-based materials. Therefore, it can cut the steel materials of high hardness and heat-resistant alloys at a high speed with slight weariness of diffusion and bond; it is featured with excellent thermal conductivity, and its flexural strength and fracture toughness is between ceramic and tungsten carbide. Due to its advantages, it is capable to make rough and semi-finishing machining of hardened steel, chilled cast iron, meanwhile, it can also be applied to difficult-to-machine materials like high-speed steel, high-temperature alloys, thermal spray etc.
CBN can also be pressed with carbide as the compact inserts. Its flexural strength can reach 1.47Gpa, and it can be repeatedly used after reground. Cubic boron nitride cutting tools is one of the optimal tools as a alternate of grinding.