THE GENERATION OF WEAR SURFACES BY THE INTERACTION OF PARALLEL GROOVES

The development of a three-dimensional analytical model for the interaction of a representative pyramidal asperity and a ductile abraded surface is described. The model predicts both the tangential frictional force and the quantitative response of the abraded material. When an isolated wear track is formed on an initially flat surface the wear mode depends mainly on the indenter angle; only relatively acute angled indenters cause micromachining. However, when parallel wear tracks interact, so that the second pass of the indenter is made through material deformed in the first pass, the distance between adjacent tracks becomes an important factor in determining the wear mode; in this case, even very obtuse indenters may lead to micromachining. Experiments to investigate the validity of the model have been carried out on a novel rig which provides very precise control over the position of asperity and counterface as well as on-board surface profile measurement. Reasonable numerical agreement is found, suggesting that it is possible to develop the model further and so to describe the gradual generation of real wear surfaces.