Tribological Properties of MoS2 Particles as Lubricant Additive on EN31 Alloy Steel and AISI 52100 Steel Ball

Abstract Main objective of this research study is to find out tribological behaviour of rolling bearing material EN31 alloy steel under lubricated conditions with various sizes of MoS 2 particles as additive by weight (0.5% and 1%) in conventional lubricant SAE 20W40. Four sizes of MoS 2 particles viz., 35 μm, 7 µm, 3 μm and 90 nm were used as additives in the lubricant SAE 20W40 on a tribo-pair consisting of EN31 steel disc and AISI 52100 steel ball. Friction and wear tests were conducted on universal tribometer equipped with high resolution piezo load sensor at three different loads (75 N, 100 N and 125 N) and sliding speed of 0.03 m/s for 10 minutes. It was observed in this study that as the size of the particles decreased, the friction coefficient and wear volume decreased which was attributed to the rolling of the small sized particles in the contact zone.