Lubrication efficiency of vegetable oil nano-lubricants and solid powder lubricants

Abstract

Reducing crude oil reserves and also environmental pollution caused by its excessive use has led to numerous researches to find alternatives to petroleum-based oils. Thus, owing to lower pollution and higher lubrication efficiency, the use of vegetable base lubricants has been widely considered. Due to the unique properties of different nanoparticles such as sphericality and high surface area besides low environmental risk, the subjected nanoparticles can be applied as additives to the base lubricants and create optimal tribological properties. In this study, in order to improve the lubricating efficiency of vegetable base lubricants, SiO2 nanoparticles with different weight concentrations were used in the cold forging process of aluminum alloy. Then, the lubrication proficiency of both nano-lubricants and conventional solid powder lubricants in the forging industry was evaluated. Friction coefficient was determined by standard compression test and friction calibration curves. In order to evaluate the lubricants’ efficiency, two key parameters, namely shear friction coefficient and surface roughness have been considered. Experimental results showed that the presence of SiO2 nanoparticles in the base lubricants significantly increased the lubrication efficiency of the base lubricants and notably reduced both the friction coefficient and surface roughness.