Lubrication of CrN Coating With Ethyl-Dimethyl-2-Methoxyethylammonium Tris(pentafluoroethyl)Trifluorophosphate Ionic Liquid as Additive to PAO 6

Abstract

This paper studies ethyl-dimethyl-2-methoxyethylammonium tris(pentafluoroethyl)trifluorophosphate ionic liquid [(NEMM)MOE][FAP] as 1 wt% additive to a polyalphaolefin (PAO 6) in the lubrication of CrN PVD coating. The tribological behavior of this mixture has also been compared with a traditional oil additive, such as zinc dialkyldithiophosphate (ZDDP). Friction and wear tests were performed by means of a ball-on-plate reciprocating tribometer, and XPS was used to analyze wear surfaces. The experimental results showed that both additives substantially improve the anti-friction and anti-wear performance of the base oil. However, the tribological behavior of the ionic liquid as oil additive does not reach that of ZDDP. The interactions of each additive with the surface and tribofilm formation contributed to improve the tribological behavior of the lubricants.