New fluorinated greases: A tribological evaluation
2005; Wiley; Volume: 21; Issue: 4 Linguagem: Inglês
10.1002/jsl.3000210405
ISSN1557-6833
AutoresP. Maccone, P. Gavezotti, Giovanna Palamone,
Tópico(s)Adhesion, Friction, and Surface Interactions
ResumoNew fluorinated greases based on perfluoropolyether (PFPE) fluids and perfluorinated polymer thickeners were prepared. Both the type of fluid (branched and linear PFPE) and the thickener (polytetrafluoroethylene, PTFE) were varied, and different oil/thickener ratios were also evaluated. The greases were characterised in terms of penetration, oil separation, and wear. Some relationships regarding the influence of both the amount and the type of thickener used were found. Torque values of ball bearings lubricated with these greases were investigated at low temperature and at high bearing speed. Specifically, the use of a new PTFE grade obtained through micro-emulsion polymerisation technology allowed the formulation of greases with a substantially reduced amount of thickener. These greases show improved antiwear properties as well as lower friction coefficients under high-speed conditions, thus paving the way to their use in applications not generally fulfilled by fluorinated greases.
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