Fundamental Wear Mechanisms on the Nanoscale

Friction and wear are coupled dynamic processes. In the nominal contact area a considerable number of asperities simultaneously experience an energy input that is often high enough to initiate plastic flow. Parallel to the flow the material intermixes with foreign elements, changes morphology and develops a new topography. The wear mechanism resembles a squeezing process that removes the flowed material. As a result, the surfaces wear with retention of its topography features in which the number of asperities and their height almost remain constant but the location of asperities continually changes.