Study of surface films of crystalline and amorphous overbased sulfonates and sulfurized olefins by X-ray absorption near edge structure (XANES) spectroscopy

摘要: In the past large synergistic effects have been reported for combinations of overbased sulfonate and sulfurized olefin in four-ball EP testing. this study, we examined effect crystallinity on formation tribofilms using X-ray absorption near edge structure (XANES) spectroscopy. Using technique, were able to differentiate carbonate from organic carbon C K-edge spectra, as well as, determining difference between FeS, FeS2, RSO3−, SO42− sulfur spectra. While calcium sulfonates do not react strongly with substrate there is evidence suggest that promotes decomposition surface form both CaSO4 which improves performance lubricant. A putative intermediate H2S can O2 Fe-rich FeSO4 respectively. new ‘FeS’ species has detected believed be a non-stoichiometric Fe-enriched FeS. Depending presence or absence either FeS favored changing concentration crystalline, C300C, amorphous, C400A, 5% 10% does appear any formation, although C300C produces more than C400A bulk.