Lubrication of PVD coatings with ethyl-dimethyl-2-methoxyethylammonium tris(pentafluoroethyl)trifluorophosphate

This paper analyses the ethyl-dimethyl-2-methoxyethylammonium tris(pentafluoroethyl)trifluorophosphate [(NEMM)MOE][FAP] ionic liquid as pure lubricant and as an additive (PAO 6 as base oil) within the lubrication of three PVD coatings (TiN, CrN and DLC). Tribological tests were performed using a ball-on-plate reciprocating machine. The results show a slight decrease in friction when the ionic liquid was used as additive in comparison with performance of neat PAO 6. [(NEMM)MOE][FAP] as pure lubricant showed the highest friction and wear reduction. The formation of tribofilms due to the ionic liquid–surface interactions improved the load-carrying properties of the coatings. These results were compared to the ones obtained with another previously studied ionic liquid which has the same anion.