Open AccessNOVEL NANOSIZED FRICTION MODIFIERS FOR ENGINE, GEARBOX AND ROLLING BEARINGS LUBRICANTS
Author(s) -
Adolfo Senatore,
Maria Sarno,
P. Ciambelli
Publication year - 2015
Publication title -
contemporary materials
Language(s) - English
Resource type - Journals
eISSN - 1986-8677
pISSN - 1986-8669
DOI - 10.7251/comen1501001s
Subject(s) - tribometer , materials science , lubricant , base oil , tribology , lubrication , graphene , friction modifier , composite material , boundary lubrication , oxide , mineral oil , metallurgy , nanotechnology , scanning electron microscope
In this paper the tribological performances of graphene oxide nanosheets in mineral oil under wide spectrum of conditions, from boundary and mixed lubrication to elastohydrodynamic regimes, are reported. Nanosheets of graphene oxide prepared by a modified Hummer method have been dispersed in Group I mineral oil. The formulated lubricant has been tested through a ball on disc setup tribometer to quantify the friction reduction with respect to the base mineral oil. The good friction and anti-wear properties of the graphene-oil mixture may possibly be attributed to the small structure of the nanosheets and their extremely thin laminated structure, which offer lower shear stress and prevent direct interaction between metal asperities in engine applications as well as gearbox environment. The results clearly prove that graphene platelets in oil easily form protective film to prevent the direct contact between steel surfaces and, thereby, improve the frictional behaviour of the base oil. This evidence is also related to the frictional coefficient trend in the boundary regime. Furthermore, hybrid organic–inorganic nanocomposites with different composition were successfully tested as antifriction and antiwear additives for grease lubricants as potential breakthrough media in rolling bearings applications.