Materials aspects in fretting

This chapter provides insight to and guidance on the range of materials-related effects that occur in fretting contacts and need to be considered when dealing with associated materials degradation problems in practice. Key strategies to improve the performance of engineering components subjected to fretting rely upon shifting materials failure from fretting fatigue to more predictable fretting wear. Approaches covered here span from simple surface hardening and single layer coatings to more complex surface engineering strategies including combinations of thermal-chemical treatments or thick hard coatings followed by deposition of soft lubricious topcoats. New and advanced techniques are being utilized to create coated surfaces which combine complex architectures and designs to deal with challenging environments in real-life applications. This includes multicomponent coatings, duplex coatings, and multilayer coatings with smart materials functionalities to allow them to respond to changing environmental conditions.