Polymer-silica additive as a modifier of tribological properties of ecological grease, improvement of fatigue resistance

The influence of polymer additive (polytetrafluoroethylene) in grease based on paraffin oil on the resistance to fatigue wear (pitting) was investigated of rolling contact. The research results revealed that grease containing a polymer caused an increase in resistance to fatigue. It was examined whether the additive affects the properties of the grease, including rheological (investigated with the use of rheometer operated in the cone/plate configuration) and thermal (determined using the Differential Scanning Calorimetry) to check their relationship with a resistance to fatigue. A scanning electron microscope equipped with an energy dispersive spectrometer was used to determine if a polymer was present on wear trace. Then the sources of chemical elements were analysed with the use of X-ray photoelectron spectroscopy to explain the improvement of resistance to fatigue. The relation between rheological properties and resistance to fatigue was shown, and the presence of polymer in friction contact was observed.