Preparation of Ni-Based SiC/WS2 Self-Lubricating Composite Coatings by Laser Cladding

Abstract

Herein, Ni-based SiC/WS₂ self-lubricating composite coatings are successfully fabricated on 45 steel using laser cladding technology. The analysis includes the examination of phase composition, microstructure, tribological characteristics, and corrosion resistance of the coatings. The results show that the coatings of A1 (5 wt% WS₂), A2 (7.5 wt% WS₂), and A3 (10 wt% WS₂) consists of γ (Fe, Ni) solid solution, Cr_0.19Fe_0.17Ni_0.11, a hard phase (Cr₂₃C₆), and lubricating phases (CrS and NiS). The addition of SiC and WS₂ enhances the physical properties of the coatings. Among all coatings, A2 exhibits the highest microhardness of 647.6 HV_0.2. The coefficient of friction (COF) of the coatings decreases significantly initially and then increases slightly with increasing WS₂ content. The formation of lubricating phases (CrS and NiS) after the incorporation of WS₂ significantly improves the tribological performance of the coatings. Additionally, A2 demonstrates the best corrosion resistance, with a corrosion current density (I_corr) of 0.44 μA cm⁻² and a corrosion potential (E_corr) of −0.374 V.