Prediction of Archard's wear coefficient for metallic sliding friction assuming a low cycle fatigue wear mechanism

A recently developed model for sliding friction, in which the frictional force is assumed to result from the pushing of waves of plastically deformed material in the soft surface ahead of asperities on the hard surface, is used to calculate the magnitude of the resulting plastic strain increments which progressively deform the soft surface. On the assumption that a low cycle fatigue mechanism eventually results in detachment of wear particles from the soft surface as a result of this cyclic working of the surface, the calculated strain increments (the magnitudes of which vary with the roughness of the hard surface and the boundary lubrication conditions) are used to estimate wear rates. The results are expressed in terms of Archard's wear coefficient and, for very smooth surfaces and good lubrication, this is predicted to have extremely low values as observed in wear tests for such conditions. For rougher surfaces and less efficient lubrication it is shown that the wear coefficient can increase dramatically.