The Effect of Hard Coated Metals on the Thermo-Oxidative Stability of a Branched Perfluoropolyalklyether Lubricant (Preprint)

M-50 and carburized Pyrowear 675(registered) steel coupons deposited with commercially available physical vapor deposited (PVD) TiN, TiCN, TiAlCN, TiCrCN/TiB4C multilayer, electroless Ni (E-Ni) TiN, and E-Ni TiCN coatings were immersed in a branched perfluoropolyalklyether (PFPAE), Krytox AC(registered), in an oxidative environment at temperatures ranging from 315 to 360 deg C for a duration of 24 hours and compared to uncoated coupons. Coated and uncoated Pyrowear 675(registered) coupons demonstrated superior corrosion resistance compared to coated and uncoated M-50, respectively. The coatings most resistant to chemical attack in the PFPAE fluid were TiCN, E-Ni TiN, and E-Ni TiCN.
Prepared in collaboration with Tribologix, Springboro, OH. Published in the Journal of Synthetic Lubrication, v24, n1, p1-17, Dec 2006.