Experimental definition of a failure model for the tribological behaviour of polytetrafluoroethylene bronze compounds

Abstract

Because of their high chemical and thermal resistance and advantageous friction behaviour, polytetrafluoroethylene (PTFE) compounds are frequently used in various engineering applications, especially for pressurized seals. To adjudge the applicability, and to establish a reliable ranking of various compounds with similar composition and micro-structure for tribological systems, a number of bronze-particle-filled PTFE materials (PTFE-Bz compounds) were investigated with a seal test system at the component level. The two best performing materials in these component tests, termed PTFE-Bz9 and PTFE-Bz14 in this article, were then selected for further, more detailed thermo-mechanical and tribological investigations on a laboratory specimen level. Furthermore, extensive failure analysis of both the worn seals and the test specimens were carried out using laser confocal and scanning electron microscopy techniques. Finally, based on the experimental results a model for describing the functionality and of the failure behaviour of these materials was developed and described.