Mechanical Properties of ZrN Coated Tungsten Carbide Coated Tool

ZrN, ZrN / Zr and ZrN / TiN / Zr coated tungsten carbide coated tool microhardness than the matrix YT15 tungsten carbide inserts (16.5GPa) is even higher, up to no transition layer coating hardness, 28.0 GPa, composite coating hardness is slightly lower. Under the same conditions of base material, zirconium transition layer of ZrN coating thickness maximum, minimum buffer layer of zirconium ZrN / TiN composite coating thickness. This is because during the deposition process, the titanium ions and zirconium ions collide with each other, resulting in the deposition speed is reduced, so that, in the same deposition time, the minimum coating thickness. No transition layer coating interfacial bonding force lower than that of the buffer layer coating, ZrN / TiN / Zr highest adhesion of the coating, no transition layer of ZrN coating adhesion to a minimum. This is due to take place between the transition layer of zirconium and composite coatings TiN and ZrN coatings YT15 matrix and ion diffusion, reducing the residual thermal stress between the coating and the substrate, thereby increasing the binding force of the coating.