Effect of Pulse Duty Cycle on Tribological Properties of Ni-Co-Al2O3-WS2 Composite Coating
Ni-Co-Al2O3-WS2 composite coating was prepared on the surface of CrNi3MoVA steel by pulse electrodeposition to improve the wear resistance of CrNi3MoVA steel.The surface morphology and phase structure of the coating were analyzed using scanning electron microscopy(SEM)and X-ray diffraction(XRD),and the nano mechanical and tribological properties of the coating were tested using a nanoindentation instrument and a reciprocating friction and wear tester.The results showed that the surface of the Ni-Co-Al2O3-WS2 composite coating exhibited nodular protrusions.With the increase of the duty cycle,the density of nodules on the coating surface decreased,and the preferred orientation of the(111)crystal plane became more obvious.The composite coating with a duty cycle of 0.1 had the highest hardness of 7.24 GPa,the lowest average friction coefficient of 0.38,and a wear rate of 1.52×10-4 mm3·(N·m)-1.The n-Al2O3 particles in the coating can support on the friction surface to reduce the contact area between the friction pairs,and at the same time,they can detach with the n-WS2 particles under shear to form a lubricating film,exerting a synergistic anti wear effect to improve the tribological performance of the coating.
万方数据
