Study on tribological properties and mechanism of antifriction and recondition additive containing nano-copper

The tribological properties of the antifriction and recondition additives containing nano-copper were studied on the effects of different types of oil under dissimilar contact forms and conditions. The NFR2 additive was found to have good antiwear and anfifriction performance: after adding it to liquid petrolatum, #16 tank oil, and 15W/30 oil. the wear spot diameter reduced by 42, 56, and 19%, respectively, and the friction coefficient decreased by 50, 49, and 33%, respectively. The negative weight gains were found after the recondition test. The NFR 1 additive exhibited promising antiwear and antifriction performance at high temperature. After using in #16 tank oil, the wear reduced by 56% and the friction coefficient decreased by 27%, while the heat-pipe oxidization properties kept unchanged. The XPS and scanning electron microscopy indicated that the reacting film was formed on the friction surface containing elements Mo, S, P, and O. The element Mo existed in +6 valence, element S in -2 and +6 valences, and element P in +5 valence.