The effect of pre-treatment of substrate on fretting tribological behavior of MoS2 coatings

MoS2 coatings were deposited by a radio frequency (rf) sputtering process on 1045 steel substrate which was pre-treated with ion-plated TiN and shot-peening processes. A series of fretting wear experiments were conducted to investigate the effects of various properties of substrate induced by different pre-treatment methods on the fretting tribological behavior of MoS2 coatings. The results showed that the fretting damage of MoS2 coating was greatly dependent on the surface characteristics, mechanical and physical-chemical properties of the substrate. The transfer and smearing of MoS2 coating in the initial wear stage, the oxidation, and delamination of MoS2 layers in the later wear process, were always subjected to the effects of mechanical properties of substrate, surface morphology, distribution of contact stress, and the adhesion strength of MoS2 coatings. Additionally, the fretting tribological behavior of MoS2 coatings was also affected by the change of its microstructure, the plastic deformation ability of the substrate and their synergistic effect.