Single point deformation and abrasion of γ-irradiated poly(tetrafluoroethylene)

During the sliding of solid bodies over one another, frictional work is dissipated which may lead to deformation or damage of one or both of the surfaces. This paper shows that it is not the magnitude of the work which controls the extent of deformation, but the way in which the work is dissipated. Three noninteracting dissipation processes are envisaged: hysteresis losses, plastic or viscoelastic ploughing and brittle fracture. Using single point scratching experiments the contributions of these processes to the total work have been estimated for a series of PTFEs whose mechanical properties have been varied by exposure to increasing levels of gamma -irradiation. This simple approach allows the wear resistance of these polymers to be estimated, and predicts the correct trend when compared with single-pass abrasion experiments.