Effect of Molybdenum Disulfide Dispersed Nanolubricants on the Tribological Properties of Mating Stainless Steel Pair

The present study focuses on the preparation of MoS2 dispersed engine oil-based nanolubricants. Standard techniques are utilized to study the shape, size, morphology of the nanoparticles and the stability of the nanolubricants. The tribological properties of mating stainless steel tribo-pairs are examined under sliding reciprocation. Effects of different parameters like type of lubricant, applied load, frequency of oscillation, and concentration of the nanoparticles on the friction and wear are investigated. Tests in the presence of conventional engine oil are carried out to set a benchmark to assess the properties of the nanolubricants. Considerable reductions in friction and wear are observed in the presence of nanolubricants. The coefficient of friction (COF) is observed to reduce in comparison with engine oil when nano-MoS2 dispersed nanolubricants are utilized. As the concentration of nanoparticles is increased, COF is observed to reduce further. The frequency and load have direct proportionality with the COF. Post-tribological analysis of wear scars help in evaluating the specific wear rate which varies directly with frequency and inversely with load. Morphology of worn surfaces reveals the mechanism of wear using nanolubricants, wherein combination of tribo-film deposition and self-mending action are identified to cause reduction in friction and wear.