| W18Cr4V has high hardness,good wear resistance and plastic,is one of the most commonly used high speed steel as the raw material of tool and die steel.In the cutting process,the interaction with the workpiece would produce high temperature,which cause the softening and wear of the high speed steel.To prolong service life of the high speed steel,a TiAlN composite coating is deposited by multi-arc ion plating on the surface of it,and the tribological properties of the coating is studied in the paper.Poor binding force with substrate is the biggest problem for TiAlN coating applying on the tool steel.In this paper,ABAQUS is used to calculate the total thickness of TiAlN coating and stresses inside the 4 coating structure models,it turns out to find that in 14μm thick coating has lowest stress,and in4 models substrate/Ti/（TiAl/TiAlN）and substrate/Ti/（TiAl/TiAlN）2 have lowest stress.The optimum parameter of the TiAlN coating are:cathode arc current Ti-60A/Al-80A,N2 partial pressure 0.5Pa,bias voltage/duty ratio 150V/80%,working temperature 350400℃,deposition time90 minutes.The TiAlN coating with the optimum parameter is 2.2μm thick,roughness is Ra0.102,microhardness HV0.11181.2,nanohardness 34.5GPa,mainly composed of TiAlN phase,with little TiN phase and AlN phase,the coating is dense and fine without any defects or pole.Scratch test and the thermal shock test are also took to explore the stress inside the 4 models,the result shows that the binding force of these two schemes are 31N and 33N,and the thickness of them are 2.8μm and 2.1μm.The wear test show that substrate/Ti/（TiAl/TiAlN）2 scheme has best wear resistance.In this scheme,the friction coefficient maintains at about 0.2 with small fluctuation under different load and slide speed,the wear loss of this scheme is the smallest one in the whole 4 schemes.In the wear test the Ti/（TiAl/TiAlN）2 coating was fine and not peeled off,the only influence to the coating are some scratches. |
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