CBN (cubic boron nitride) was first synthesized by General Electric (GE) Company in the 1950s under high temperature and high pressure by manual method. Its hardness is second only to diamond but much higher than other materials. Therefore, CBN and diamond are collectively referred to as superhard materials.
Cubic boron nitride (CBN) polycrystalline sintered body is mainly prepared by sintering CBN powder and a small amount of binders (such as CO, Al, Ti and tin) at the pressure of 4000-8000 MPa and temperature of 1300-1900 ℃;
The polycrystalline sintered body with cemented carbide substrate was prepared by sintering the cubic boron nitride powder and binder as a layer and cemented carbide (sheet or powder) as a layer under the above pressure and temperature;
At the same time, the original physical and chemical properties of CBN can be maintained, and the disc with diameter up to 16mm can be made. After being cut into proper shape, CBN can be used as the tool head of turning tool and boring tool, which is suitable for cutting hardened steel, cast iron and nickel alloy.
CBN is a kind of material whose hardness is second only to diamond (diamond), so CBN blade belongs to superhard material tool. Because CBN can withstand the high temperature of 1300~1500 ℃, CBN blade can carry out high-speed cutting of ferrous metals at high temperature without chemical reaction, with high machining accuracy, low surface roughness and cutting life 5-10 times longer than cemented carbide tool.
CBN tools have been widely used in many metal cutting industries because of their excellent properties such as high thermal hardness, high wear resistance and not easy to stick.
The application scope mainly includes the following difficult to machine materials:
All kinds of quenched steel, such as carbon tool steel, alloy steel, bearing steel, die steel, high speed steel, etc
Thermal spraying materials, such as Ni based and Fe based products
Wear resistant cast iron: such as V-Ti Cast Iron, high phosphorus cast iron and chilled cast iron, etc