Tribological Performances of Dicationic Ionic Liquids at Elevated Temperature

Ionic liquid 1, 6-bis (3-hexylimidazolium-1yl) hexylene hexafluorophosphate was synthesized. The kinetic viscosity and mass density of the ionic liquid were determined. The tribological performance of the ionic liquid for steel/Cu-Sn alloy was evaluated on an Optimol SRV oscillating friction and wear tester under ambient conditions. Benzotriazole was used as lubricant additive in ionic liquid to inhibit tribo-corrosion from Ionic liquid 1, 6-bis (3-hexylimidazolium-1yl) hexylene hexafluorophosphate . The worn surfaces on Cu-Sn alloy disc were analyzed by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). SEM results show slight abrasion and tribo-corrosion on the worn surfaces when BTA was used. XPS results indicate boundary lubrication film was composed of Cu₂O and CuO by the tribochemical reactions of ionic liquid with Cu-Sn alloy during the sliding process.