The effect of Si content on the structure and tribological performance of MoS2/Si coatings

Abstract In the present work, the synthesis of MoS2/Si coatings was conducted to study the effect of Si on the microstructure of the MoS2/Si coatings and their tribological behavior. With the adoption of advanced characterization methods, the results reveal that the introduction of Si plays significant roles in determining the morphologies and structures of the MoS2/Si coatings. The results demonstrate that the increase of Si content can cause the changes of the coatings from a typical porous with columnar morphology to a non-porous with featureless morphology, while as the Si content continues to increase up to a much higher content (i.e., 17.3 at.%) the coatings with composite structure change to the a multilayer nanostructure. The tribological tests results point out that the MoS2/Si coatings with a composite structure perform better tribological properties as the content of Si rises from 0 to 14.7 at.%, owing to the combination of the increase in hardness and the oxygen gettering effect of Si. However, the MoS2/Si coatings with a multilayer nanostructure formed under a much high Si content (17.3 at.% Si) display poor tribological properties as the excessive Si inhibits the formation of the transfer film upon severe three-body abrasive wear.