Cemented Carbide Coated Tool Coated Substrate Gradient

The bonding strength of the coating and cemented carbide coated tools alloy matrix is key carbide tool life, the coating must be suitable substrates therewith can combine to achieve the desired performance. Not the same material as each of the thermal expansion coefficients are different, probably because of the thermal stress cracks in the coating during cooling. Due to the brittle cemented carbide coated tool coating material, usually easier to crack the coating to the substrate surface extension. Gradient of substrate processing, the surface area of the coated substrate forming ductile region cubic carbides and carbonitrides, the binder content in this region is higher than the nominal binder content of the coating substrate; when the coating formed when the crack growth to the region, because of their toughness, crack propagation can absorb the energy, it is possible to effectively prevent the crack to the inside of the alloy expansion, improve the performance of cemented carbide cutting tools.