Archard wear and component geometry

The wear performance of tribological material pairs is commonly assessed by experimental investigations which make use of rigs incorporating a pin-on-disc geometry. The information so generated is conventionally interpreted in terms of a linear relation between wear volume, applied load and sliding distance in accord with the Archard wear equation. An appropriate material parameter is thus the so-called dimensional wear rate usually measured in mm 3 /N m. However, there are many practical situations in which, as components wear, the area of apparent contact changes so that, although the Archard relation may still be applicable on the microscale, the relation between either the macroscopic wear dimension, or the total wear volume, may be other than a linear function of sliding distance or load. The following examples are considered: a spherically ended pin sliding or rotating against a flat, a pair of crossed cylinders, a radially loaded journal bearing and a radially loaded spherical bearing. Data from the wear literature are examined in the light of the analyses presented.