X-ray absorption near edge structure (XANES) andconversion electron Mössbauer spectroscopy (CEMS) study of perfluoropolyalkylether based additives

This study provides critical insight regarding the interactions of perfluoropolyalkylether (PFPAE) additives with Fe-based alloys. PFPAEs are primary candidates for the development of high temperature liquid lubricants for the next generation of turbine engines because of their chemical and thermal stability. However, a PFPAE must be tailored for its particular application by the addition of soluble additives. Currently, two additives that show promise for improved performance are a substituted triphenylphosphine and a bis-substituted benzothiazole. To date, little work has been reported on the mechanism by which these additives actually improve overall performance. In order to gain some understanding of how these additives work, a series of oxidation-corrosion tests were performed using these additives in Demnum with the resulting coupons examined by X-ray absorption near edge structure (XANES) and conversion electron Mössbauerspectroscopy (CEMS).