Damage that involves the cumulative and gradual removal of material from surfaces. Three types of wear are described below:
Abrasive Wear â€“ Damage that occurs when surfaces are in contact and undergo relative motion, and cutting or abrasion by hard particles (usually a contaminant) remove material from the surfaces.
Adhesive Wear â€“ Damage that occurs when two surfaces are in contact and undergo relative motion, and high loads and/or temperatures cause asperities on these two surfaces to weld together and then immediately tear apart, removing material from one or both surfaces. Adhesive wear can be mild (frosting), moderate (scuffing), or severe (galling, scoring, seizing).
Corrosive Wear â€“ Damage that occurs when chemical reactions at a surface result in the removal of material. Corrosion can be localized (e.g., pitting) or general (not local).