High temperature friction and wear behavior of MoS₂/Nb coating in ambient air

MoS₂ coatings are well-known for their solid lubricant properties and used as self-lubricants in vacuum and inert gas environments, and such coatings are not used in atmospheric conditions because of their deteriorating tribology. The tribological performance of MoS₂ solid lubricant coatings in the different atmospheres has been improved by the codeposition of a small amount of another metal. In this study, the tribological behavior of MoS₂/Nb coatings was investigated in ambient air at temperatures up to 500°C by using high-temperature pin-on-disc tribo testers and alumina balls as counterfaces. MoS₂/Nb coatings were deposited on silicon wafers and AISI 52100 steel substrate by closed-field unbalanced magnetron sputtering. The structural analyses of the coatings were performed using X-ray diffraction and scanning electron microscopy techniques. The hardness was measured using a microhardness tester.