Microstructure, wear and corrosion resistance of Ni-based composite coating by multi-layer laser cladding

Abstract

Using laser cladding technology to prepare coatings on the gear ring of the main wheel made of ZG42CrMoA, the composite coatings consisting of γ-Ni, MC, NiB, WC, and WC. As the amount of WC nanoparticles increased, a "pinning" effect on dislocations hindered dislocation movement during wear, Comparative analysis showed a reduction in wear rate by 76.94 % and 72.80 % compared to the untreated substrate and high-frequency quenched substrate, respectively. Further, finite-element analysis indicated maximum compressive stress values of 274.37 MPa and 262.20 MPa during the impact and friction phases, respectively. This was lower than the corresponding values of the high-frequency quenched layer, which were 288.63 MPa and 283.16 MPa. The corrosion current density of the composite coating reduced by 87.98 % and 92.71 % compared to the untreated substrate and the high-frequency quenched substrate, respectively. Additionally, the electrochemical impedance amplitude of the composite coating was 72,456 Ω, which was substantially higher than that of the high-frequency quenched substrate (1270 Ω) and the untreated substrate (1717 Ω) by 570.5 % and 422.0 %.