New Types and Structure of Coated Cemented Carbide

As we know, diamond is the hardest material in the world so far. It has high density (3470-3560kg/m³), high hardness (Mohs’ scale of hardness is 10), high melting point (3550℃-4000℃). Although diamond has Surface Milling Inserts stable chemical property and excellent wear resistance, it is difficult to manufacture the required parts or products directly. Therefore, diamond coating by CVD (Chemical Vapor Deposition) can effectively solve the problem, which is widely used in the mould of metal wire processing. Diamond coating deposits a layer of polycrystalline diamond film on tungsten carbide matrix mainly by low pressure chemical vapor deposition (LPCVD), it can remarkably improve the hardness and wear resistance of tungsten carbide.

Take the consumables of metal wire as an example, drawing die mainly includes two kinds that tungsten carbide mould and polycrystalline diamond mould in the wire industry, while the quality, the efficiency and the comprehensive properties of metal wire is greatly determined by the properties of drawing die. Tungsten carbide mould has good hardness and toughness, the production cost is lower than polycrystalline diamond, but it is easily adhered by compounds so that its service life is shorter than polycrystalline diamond; polycrystalline diamond has excellent hardness and wear resistance, and it has higher mould cost, it is difficult to manufacture the larger size and abnormal mould, which has lower plasticity and toughness. Diamond coated cemented carbide mould by LPCVD not only combines with both advantages of diamond and tungsten carbide, but also overcomes the defects of them, which is one kind of the most widely used new drawing die. The sketch of drawing die working as follow: