Experimental Investigation on the Wear Performance of Nano-Additives on Degraded Gear Lubricant

This study investigates the degradation of a commercially available gear lubricant and potential nano-additives to mitigate such degradation. Initially, we performed an experimental on chemical API GL-4 EP90 by mixing different concentrations aqueous hydrochloric acid (aqueous HCl) varying from 0.0005% v/v up 0.0025% v/v, while maintaining overall water content in oil below prescribed limits. The was monitored using pH value, total number (TAN) attenuated reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) analysis. experiments were developed test rig conventional as well chemically aged oil, corresponding results value wear debris recorded. Based results, empirical regression model between concentration HCl aging time has been established. Under lubricant, severe observed, which motivated us explore suitable nano-additive minimize wear. three nano-additives—graphite, graphene, “graphene oxide functionalized with silicon (GO@SiO2)”—were chosen. A series tests conducted design method (L8 L16 orthogonal array) investigate effect find optimum additive for performance. Finally, setup degraded optimized nano-additive. Overall indicate very significant contribution decreasing