Performance of Perfluoropolyalkylether Oils Under Boundary Lubrication Conditions

摘要

Perfluoropolyalkylether (PFPE) oils and oil-based greases are being used with increasing frequency on spacecraft as a result of their purported outstanding properties. We demonstrated that, under boundary lubrication, these materials degrade by way of an autocatalytic mechanism. As a result, they have serious limitations in this tribological regime primarily because of the inability of the PFPE fluids to dissolve antiwear additives. To augment the fundamental studies, a series of wear tests comparing PFPE oils and greases with hydrocarbon fluids under boundary conditions were performed. As predicted, the performances of the PFPE fluids were below that of the hydrocarbon fluids. The results of the wear tests are discussed in terms of the effect of additives on the PFPE degradation mechanism and the overall usefulness of the PFPE fluids under boundary lubrication conditions.