Study On The Lubricating Property Of Carbon Nano-particles With Four Kinds Of Dimension

The isomers of carbon element are the most comprehensive and affluent indimension and microstructure, including fullerene, carbon nanotubes, graphene andgraphite. In this dissertation, dispersion and lubricating performances of carbonnano-additives were investigated in the lubricating oil, and their mechanism wasproposed.Oleic acid is the most effective surfactant to improve the dispersion stabilities ofcarbon nano-additives in the lubricating oil, and its optimal concentration is2%. Theulrasonicated dispersion is helpful to improve obviously the dispersion efficiency andstability of carbon nano-additives. The optimal uhrasonicated time of nano-graphiteand graphene is30min, but the CNTs’ is120min. The methods combined oleic acidwith ulrasonicated dispersion can improve the dispersion stabilities of nano-graphite,CNT and Graphene in the lubricating oil.A four-ball machine was used to investigate the lubricating properties ofnano-graphite with three diameters, CNT, graphene and fullerene, the wear scars wereanalyzed by SEM. The results indicate graphite has excellent properties of anti-wearand friction-reducing, and the property of extreme pressure. Graphene also has goodproperties of anti-wear and frication-reducing, especially the anti-wear property ofGraphene with200ppm concentration at high load. The CNTs with50ppm and100ppm concentration have good anti-wear properties at low&middle load,friction-reducing property at high load. Fullerence with above100ppm concentrationhas good anti-wear property at high loads. The combinations of fullerence and CNT&Graphene have satisfying results and obviously improve the lubricating properties inthe lubricating oil.Accord to the results of the lubricating properties of different carbonnano-additives, their lubricating mechanisms were modelling. The concept ofdispersion degree was suggested according the used concentration with the bestlubricating properties.Nano-graphite has good anti-wear and friction-reducing properties in aviationgreases, and the combinations of nano-graphite and MoS2improve obviously thelubricating properties at high loads, broaden the used load range and universalproperties of aviation greases.All in all, carbon nano-additives have good lubricating properties in the lubricating oils and greases, and have a wide application foreground in the lubricationfield.