In materials science, wear is the erosion of material from a solid surface by the action of another surface. It is related to surface interactions and more specifically the removal of material from a surface as a result of mechanical action. The need for mechanical action, in the form of contact due to relative motion, is an important distinction between mechanical wear and other processes with similar outcomes.Williams, J. A. (2005). "Wear and wear particles - Some fundamentals." Tribology Int… (More on Wear)