Effect of nano-La2O3 doping on the tribological behavior of laser cladded WC-12Co coating on 65Mn steel under water lubrication condition

Abstract

In this study, the effect of nano-La2O3 doping on the tribological behavior of laser cladded WC-12Co coating on 65Mn steel under water lubrication is investigated. The microstructure, hardness and wear resistance of the composite coatings prepared by the optimum doping amount of La2O3 were evaluated. The results show that the hardness of nano-La2O3 doped WC-12Co composite coating is 260% of the substrate, which significantly improves the wear resistance of the substrate. The tribological mechanism of the composite coating is clarified as the direct contact of the friction surface, synergistic lubrication of ZrO2 and boundary film and mixed lubrication by micro-structural and element-distribution analysis of various worn surfaces under different working conditions (load and sliding speed).