Reaction of Perfluoroalkylpolyethers (PFPE) with 440C Stainless Steel in Vacuum Under Sliding Conditions at Room Temperature.
Abstract
Reactions of the perfluoroalkylpolyethers (PFPE) Fomblin Z25, Demnum S200, and Krytox 16256 were studied during sliding contact with stainless steel (440C) specimens under ultra-high-vacuum conditions. All three fluids reacted with the steel specimens during sliding. Fomblin, which has acetal linkages, decomposed under the sliding conditions and generated gaseous products, namely, COF2 and fluorinated carbons, which were detected by a quadruple mass spectrometer. Gaseous products were not detected for the Demnum and Krytox fluids. The amount of gaseous products from Fomblin increased with increasing sliding speed. At the end of the sliding experiments, the wear scar and the deposits on the specimens were examined by small-spot-size x-ray photo-emission spectroscopy. The oxide layer on the specimen surface was removed during sliding, and metal fluorides were formed on the worn surface. The surfaces of the wear scar and the deposits were covered with adsorbed PFPE. On the basis of these results, it was concluded that the decomposition reaction of Fomblin began when the fluid contacted the fresh metal surface formed during sliding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1989
- Accession Number
- ADA310448
Entities
People
- Shigeyuki Mori
- Wilfredo Morales
Organizations
- Glenn Research Center