CBN (Cubic Boron Nitride) was first synthesized in the 1950s by American general electric (GE) under high temperature and high pressure by the artificial methods. Its hardness reaches HV8000, which is second only to diamond (HV10000) and much higher than other materials. It and diamond are collectively known as superhard materials.
CBN crystal and diamond crystal belong to sphalerite type, and the lattice constant is similar, the chemical bond type is the same, so CBN has the hardness and compressive strength close to the diamond, and because it is composed of N, B atoms, it has higher thermal stability and chemical inertia than diamond.
The manufacturing method of CBN tool material is mainly the hot pressing method. The original material of pressing CBN single crystal powder — hexagonal boron nitrous oxide powder (HBN) is placed in the chamber of leaf wax, and the catalyst is added. With a hydraulic press with six or two heads, the CBN single crystal powder is formed under 1600℃ and 5 ~ 6GPa under 10min of hot pressing. Single crystal powder can be used in abrasives and abrasives. With the CBN single crystal powder plus catalyst and binder, at 1800℃, 5 ~ 6GPa under the pressure of 3 minutes can be obtained PCBN overall blade or composite blade (cemented carbide backing, there is 0.5mm left and right CBN thin layer).
Demina tool grinding machine can grind the CBN tools with high quality.
