Mohan, N., Sharma, M., Singh, R., and Kumar, N., "Tribological Properties of Automotive Lubricant SAE 20W-40 Containing Nano-Al2O3 particles," SAE Technical Paper 2014-01-2781, 2014, doi:10.4271/2014-01-2781.
The need for advanced lubricants is increasing rapidly due to the current wide range of operational usage, i.e., high loads and speeds of motion between friction pairs, broader temperature range, and the overall requirements for increased reliability and service life of machinery. It is essentially important to develop specialized anti-friction and anti-wear materials that will help in preventing wear and decreasing friction, thereby saving fuel and electricity. Simultaneously, such materials are also expected to reduce vibration, noise and maintenance of machine parts. Thus, the research into extending the service life of such materials continues to be imperative. Nanoparticles (NPs) present a novel approach in this regard, as they can be used in lubricants in between two mating contact surfaces as a third body. When compared with the widely used conventional micro-particles for tribological applications, NPs have unique features owing primarily to their much higher specific surface area. This is true for studies of both nanostructured coatings of friction surfaces as well as for new lubricant compositions containing Nanoparticles. When compared to a pure fluid, this category of fluids containing nanoparticles (1-100 nm) has displayed fascinating behavior during experiments including augmented heat transfer coefficient and higher thermal conductivity. The products so developed can find applications in metal working fluids, industrial gear oils, and automotive gear lubricants, either alone or in formulations. Present research investigates the influence of NPs as lubricant additive on the relative motion of a plane surface over the other having circular surface in contact. A pin-on-disk setup as per ASTM G99 has been used to conduct the experiments in starved and fully flooded conditions at various loads and relative speeds at the pin and disc contact. The lubricant SAE 20W-40 with nano-additives has been used to study the influence on friction and specific wear rate at the interface. Based on the experiments, tribological behavior of lubricant with NPs has been compared with the lubricant without NPs. The coefficient of friction and specific wear rate were found to be decreased in lubricant containing NPs. The addition of NPs to the lubricant SAE 20W40 has proved to be profoundly promising in reducing the friction and specific wear rate.