Design aspects for advanced tribological surface coatings

A holistic approach to the study of the important tribological contact mechanisms is described, which provides a basis for effective coating design. The mechanisms include macromechanical effects, defining the stress fields, and these are influenced by the hardness, thickness and surface finish levels of coatings and substrates. Micromechanical mechanisms influence cracking. Tribochemical mechanisms can also determine friction and wear performance. Material transfer is another influencing mechanism, and nanomechanical mechanisms at the atomic level influence friction. Examples are given of coatings and treatments that fulfil the needs of these mechanisms in a range of different contact types.