TRIBOLOGICAL PERFORMANCE OF HIGHLY FINE NICKEL-MOLYBDENUM DISULFIDE POWDERS ADDITIVE TO LUBRICANT OIL

Wear is a phenomenon which is surface materials damage or loss between two contact solids surfaces in sliding, rolling, or impact movement. In most cases, wear is caused by the interaction of surface asperities. To reduce the energy loss and equipment damage generated due to the mechanical parts friction in the operation, around the world is stepping up developing appropriate lubricants and lubrication technology. Molybdenum is one of the major refractory metals (metals with very high resistance to heat and wear). As already noted, for lubricant compositions as fillers can be used soft powder (anti-friction) of metals – nickel. This work focuses on studying an urgency and favorable prospects of practical use of firm powder additives on the basis of MoS2 which particles are coated with one layer of soft metal (Ni), and their effect on tribological characteristics of lubricant oil (SAE 50) at a range of concentration (2 – 8) wt%. Optimum lubricating effect concluded on the level of concentration of the composite additive powder in the range of (3.5 – 4.5) wt %, by the formation of protective boundary layer between sliding tribosurfaces that prevents wear. Tribological characteristics significantly improved i.e.friction coefficient may drop about (1.5-2) times, and the wear rate about (3-3.5) times compared with the case of usig the lubricant oil without additives.