Wear behavior of environment friendly trimethylolpropane trioleate-based lubricant

Abstract

Purpose Formulation of mineral-based specialty lubricants without anti-wear (AW) and extreme-pressure (EP) additives is a challenging task. This study aims to propose an environment friendly alternative to mineral-based lubricants with superior wear preventive characteristics. Design/methodology/approach In this study, analysis of wear under trimethylolpropane trioleate (TMPTO)-based lube using operating parameters of four-ball tester was done. The effects of type of lube oil, temperature, load and speed on specific wear rate were investigated using Taguchi L27 orthogonal array. Based on the Taguchi experimental results and single-to-noise ratios, ranking of the four ball parameters was done. The surface analysis of worn steel balls was carried out using optical microscopic images of wear scar and energy dispersive spectrometry (EDS). Findings Results depict that the blend of sulfurized additives with TMPTO base oil showed a synergistic effect in terms of reduction in specific wear rate by the formation of protective film layer on the surface. The possible physical or chemical interactions between base oil and additives were studied based on the surface morphology of test balls. Practical implications The formulated lubricant has the potential to be used as a tapping/broaching oil. Originality/value To the best of the authors’ knowledge, the paper is a novel study investigating the effect of different additive in TMPTO. The results could prove beneficial in making TMPTO-based lube oil a viable replacement of mineral-based oils.