Tribological behaviour of Ni/WC–MoS2 composite coatings prepared by jet electrodeposition with different nano-MoS2 doping concentrations

Ni/WC-MoS 2 composite coatings were fabricated in electrolytes with different MoS 2 doping levels using jet electrodeposition. We investigated the surface characteristics of Ni/WC-MoS 2 composite coatings, including the composition, surface morphology, microhardness and tribological behaviour. We also analysed the Ni/WC-MoS 2 composite coating wear mechanism during the wear process. The outcomes determined that Ni/WC-MoS 2 coatings had better surface quality, smaller grain size and larger coating thickness than Ni/WC coatings. The doping of MoS 2 promoted the deposition of WC in the coatings, which further enhanced the microhardness of the coatings. The Ni/WC-MoS 2 composite coatings doped at a MoS 2 concentration of 5 g/L exhibited a maximal microhardness of 730 HV 0.1 . Doping by MoS 2 effectively minimized the coefficients of friction ( CoFs ) of the composite coatings to 0.3. During the wear process, the repair effect of MoS 2 and formation of oxidised friction films transformed the adhesive wear into oxidative wear assisted by abrasive wear, which improved the abrasion resistance of the coatings and diminished the wear rate. The wear rate of the Ni/WC-5 g/L MoS 2 composite coating decreased by 47.34 % in comparison with that of coatings without MoS 2 doping, which was 7.44 × 10 4 μm 3 /N∙m. The findings indicate that doping MoS 2 can effectively enhance the surface wear resistance. This research provides a practical approach to prolong the service life of metal parts.