The effect of hard coated metals on the thermo‐oxidative stability of a branched perfluoropolyalkylether lubricant

Interaction of fomblin® lubricant with surface nitrided and/or coated bearing (M50) steel

“…The higher binding energy peak (F-C) is a result of the physisorbed fl uid on the surface and the lower binding energy peak is due to metal fl uoride, viz. Fe-F. 12 The larger peak height of the Fe-F peak indicates severe interaction of the fl uid with the M50 coupon. No Fe-F peaks were observed on the surface of the OC-tested nitrided, nitrided and/or coated samples (Figure 8b-8d), indicating minimal interaction with the fl uid.…”

“…8 The second approach is to coat the metal surface with a protective material. [9][10][11][12] The third approach can be considered as a combination of the two. The present work deals with the use of surface coatings to minimise or eliminate the fl uid /metal degradation.Previous studies have shown that the chemistry of the commercially available TiN coating is very effective in preventing the interaction between PFPAE and bearing steel.…”

“…It has been found that fl uid can penetrate through the pin holes present in the coating microstructure and react with the underlying steel (metal), causing corrosion. 11,12 To prevent the interaction of fl uid with the metal through the pores in the TiN coating, electroless Ni (E-Ni) coatings that are approximately 20-25 µm thick have been used as an intermediate layer 11,12 between the TiN coating and the steel substrate. This idea was based on the observation that Ni alloys resist degradation by PFPAE.…”