Wear in relation to friction — a review

Soft or hard film coating, multi-phase alloying and composite structuring have been developed to control wear and friction by improving materials and surfaces with some aspects for better properties of friction and wear. On the other hand, it is well recognized recently that the coefficients of friction and wear are not material properties but two kinds of responses of a tribo-system. They are always reasonably related with each other when the necessary functions of the tribo-system are well considered. Typical wear behaviors of representative materials of coatings, composites, metallic alloys and ceramics are reviewed in relation to their friction behaviors, and fundamental mechanisms of wear are confirmed for the technical development of wear control.