Relationships between the Wear of Polymers and their Mechanical Properties

Abstract

The influence of some mechanical properties of polymers—hardness, elastic modulus, breaking strength and elongation to break—on their wear rates against a metal counterface has been determined at various temperatures. Many polymers exhibit a minimum wear rate at a particular temperature. The relative proportion of plastic to elastic deformation, characterized by the ratio of hardness to elastic modulus, is almost independent of temperature for most polymers. Variations in this ratio are therefore insufficient to explain the observed changes in wear rate. In contrast, the product of the breaking strength S and the elongation to break is a very significant parameter. In conditions of abrasive wear, there is an approximately linear relationship between the room temperature values of 1/ Sε for a large number of polymers and their wear rates. In steady-state sliding conditions, however, this relationship no longer applies because of the complicating effects of transfer of polymer to the counterface.