An overall review on the tribological, thermal and rheological properties of nanolubricants

ABSTRACT Nanolubrication is one of the recent innovative technologies used in lubrication science. It involves dispersion of various types of nanoparticles in different concentrations in the conventional lubricant and studies the tribological properties of these lubricants on a particular tribopair under different operating parameters. Nanoparticles can be considered as potential lubricant additives. They present several major advantages compared to organic molecules currently used as lubricant additives, which include their nanometre size allowing them to enter the contact area easily. The real contact area is decreased when nanoparticles are entrapped between the mating surfaces. They are often efficient at ambient temperature. Thus, no induction period is necessary to obtain interesting tribological properties. Further, nanoadditives also improve the thermo-physical properties of the lubricant. A comprehensive review is provided with the aim to analyse and explore tribological and thermo-physical properties of nanolubricants on various tribopairs used for engineering applications. Recent advancements like hybrid nanofluids and biolubrication are also discussed that further provides the solutions for sustainable lubrication.