Effects of current-carrying conditions on lubrication and tribological performance of ionic liquid

Ionic liquids are considered to be ideal electronically controlled friction and lubrication media because of their excellent lubrication and electrical conductivity. However, systematic research on the lubrication performance and friction principles of ionic liquids under current-carrying conditions is lacking. In this study, the lubrication and friction properties of an ionic liquid under different carrying-current conditions and the effect of addition of Fe3O4 nanoparticles on its tribology were investigated using a current-carrying friction and wear tester and analyzed in detail. The experimental results showed that the lubricating ability of the ionic liquid improved under lower current intensity conditions, resulting in a slight decrease in the friction coefficient between the friction pairs. However, as the current intensity increased, the ionic liquid lubrication adsorption film was destroyed by the current breakdown, resulting in a significant increase in the friction coefficient between the friction pairs. These phenomena suggest that the friction and lubrication performance of the ionic liquid could be actively controlled by applying a current. Simultaneously, the addition of Fe3O4 nanoparticles further improved the friction enhancement effect of the ionic liquid under a high current intensity. These effects were related to the controlled formation and failure of the ionic liquid lubrication adsorption oil film under the current-carrying conditions.