Tribological Properties of Motor Oil with Nanodiamond Additive tested for steel friction surfaces with different hardnesses

Abstract

Synergistic compositions of detonation nanodiamond (ND) particles in the form of 100nm aggregates in combination with molybdenum dialkyldithiophosphate were used as additives to 10W40 oils. Ring-on-disk tribological tests were performed under high load conditions using friction pairs with different hardnesses, namely normalized-normalized (“soft/soft”) and normalized-quenched (“soft/hard”) steel samples. For the “soft/hard” steel friction pair NDs provide significant reduction in both the coefficient of friction and wear as well as demonstrate polishing. For the “soft/soft” steel friction pair, however, no difference in the coefficients of friction was observed when the base oil was used with or without ND. In the test with oil containing the ND additive, the wear scar in the disk was wider, but more shallow, than in the test with pure oil. Current tests indicate that the significance of the reduction of friction and wear of the sliding surfaces in the presence of the ND additive in oil strongly depends on the hardness of the friction surfaces and most probably is connected with ND polishing effect.

Detonation Nanodiamond as a New Option for Reduction of the Viscosity of one Novel Di–azide Functionalized Monocationic Ionic Liquid

“…Among the various nanoparticles, nanocarbon‐based additives play a special role due to their high biocompatibility providing reduced environmental impact effect. Studies of lubricating compositions including detonation nanodiamond (DND) and reduced graphen oxide (r‐GO) as additives, have demonstrated their positive impact to reduce the system's internal friction of these compounds, often superior to other nanoparticles . Moreover, graphene, graphene oxide (GO) and r‐GO have large specific surface area, high surface‐to‐volume ratio and chemical stability.…”