Tribological study of MoS 2 -based composite coating on steel surface

Self-solid lubricant Molybdenum disulfide (MoS₂) coatings have rapidly gained popularity in vacuum environments. The pure MoS₂ coatings lose their lubricating properties under humid conditions. The properties of MoS₂-coated film can be enhanced by incorporating a small amount of metals. In this paper, we have deposited the films of MoS₂_Al_Ti composition (90% MoS₂, 5% Al, 5% Ti) with the variation of different RF power through a magnetron sputtering system and investigated the tribological and mechanical performance of metal-doped MoS₂ films on stainless steel (SS) 321 substrates. The elemental composition, surface microstructure, film thickness, tribological and mechanical behavior of as-deposited films were analysed by EDS, FESEM, multi-tribometer, and micro-indentation, respectively. The results showed that we got an optimized composite film of MoS₂_Al_Ti, which has a 0.01 friction coefficient for better lubrication performance, relatively less wear rate (9.0 × 10⁻⁵ mm³/N-m), and prevents oxide layer formation.