Ecofriendly Protic Ionic Liquid Lubricants for Ti6Al4V

Three diprotic ionic liquids (PILs) containing bis(2-hydroxyethyl) ammonium cations and citrate (DCi), lactate (DL), or salycilate (DSa) hydroxy/carboxylate anions were studied as lubricants for Ti6Al4V–sapphire contact. At room temperature, the neat PILs are non-Newtonian fluids, which show up to a 70% friction coefficient reduction with respect water. New aqueous developed using 1 wt.% additives in The new (Water + PILs) showed reductions of higher than 50% water at temperature. lowest coefficients temperature achieved thin lubricant layers deposited on Ti6Al4V Water PIL after evaporation. 100 °C, best tribological performance, wear rates, was obtained aliphatic anions: DCi, DL. surface sapphire balls mild adhesion abrasion mechanisms observed via scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), photoelectron (XPS).