In materials science, wear is the erosion of material from a solid surface by the action of another solid. The study of the processes of wear is part of the discipline of tribology. There are five principal wear processes: Adhesive wear Abrasive wear Surface fatigue Fretting wear Erosion wear The definition of wear doesn't include loss of dimension from plastic deformation, although wear has occurred despite no material removal. This definition also fails to include impact wear, where ther… (More on Wear)