The mechanism of formation of boundary lubricating films during friction in a medium of di(2-ethylhexyl) sebacate

Abstract

In this work, the mechanism of formation of boundary lubricating films during friction in synthetic oil di(2-ethylhexyl) sebacate (DEHS) was studied. The study of the kinetics of the interaction of DEHS with the metal surface showed that the formation of the boundary film proceeds in the first 40 s of friction. The unoxidized iron detected by the XPS method on the friction track accelerates the chemical transformations of lubricant molecules. Removing the oxide film from the friction surface is a mechanically activated process. When DEHS interacts with the iron surface, the reactions of decarboxylation of molecules proceed, as a result free radicals are formed. The sequence of transformations of free radicals and compounds with CC bonds leads to the formation of surface films upon friction. The retention of the film on the surface occurs due to the forces of interaction of the metal with free radicals or unsaturated bonds of organic molecules.