Influence of Ionic Liquids and Ag Nanoparticles as Lubricant Additives on Electrically Induced Bearing Damage

In electric vehicles and similar applications, leakage currents threaten lubricated bearing and gear interfaces, leading to significant surface damage such as micro-pitting. This damage is typically caused by electrical arc or plasma initiation, resulting in localized rapid temperature rises. Recent studies have highlighted the potential of oil-soluble ionic liquids (ILs) as promising antiwear (AW) additives. However, their effects on improving the electrically induced bearing damage are yet to be explored. Also, Ag nanoparticles have proved to be significantly effective in reducing electrically induced micropitting when added with grease. Further investigation is required to determine the effectiveness of Ag nanoparticles in lubricants without grease thickeners. Therefore, this research investigates the impact of ionic liquids and Ag nanoparticles as additives in PAO-based lubricants on electrically induced bearing damage. Reciprocating rolling sphere-on-disk tests were conducted under electro-tribological loads using E52100 steel samples. Surface analysis using optical spectroscopy and scanning electron microscopy (SEM) was carried out for quantifying surface damages.