Tribological characteristics of synthesized hybrid nanofluid composed of CuO and TiO2 nanoparticle additives

Abstract

Friction and wear are inherent in the interfacing elements of machine components having relative motion. As per estimates, up to 30% of the total energy consumed is lost in overcoming friction. It can be minimized by development of material for surface enhancement, and with the proper application of lubricant. The accessibility of nanoparticle manufacturing facility promoted its use in lubricant. In last decade investigations have been made to find the optimum content of a single type of nanoparticle additive to improve desired tribological property to a certain extent. The main objective of the present research is to further enhance the tribological characteristics by use of combination of two different nanoparticles as additives. Gear oil EP 140 is considered as a base oil. Copper oxide (CuO) and Titanium oxide (TiO2) nanoparticles have been blended in different concentrations to the base oil for formulation of the hybrid nanofluid. Anti-wear tests and extreme pressure tests were performed on the Four-ball tribo-tester to investigate the coefficient of friction, wear prevention property, and load-carrying capacity of the nanofluid. Measurement of wear scar diameters (WSD) and characterization of the balls scar were performed using optical microscopy, scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) tools. Anti-wear tests of the nanofluids showed promising results with a remarkable reduction of 19.33% in the coefficient of friction and a significant reduction of 23.03% in the wear. The load-carrying capacity (poz) has increased by 89.24% with the addition of CuO and TiO2 nanoparticles in comparison to the base oil. The promising results of the hybrid nanofluid can lead to improvement in performance and significant saving of energy consumption in machinery especially the gearbox.