Wear is generally described as the progressive material loss on the surface of a solid body. It is caused by the contact and/or relative movement of your component with a solid, liquid, or gaseous counter body.
In essence, any form of wear is based on four wear mechanisms:
- Abrasive wear – when a hard body penetrates into the softer surface of the component and causes surface abrasion through that.
- Adhesive wear – the tearing of the material from of the component surface due to high adhesion forces. A requirement for this is that surfaces are in contact/adhered to one another under high surface pressure. Once the resulting adhesion forces exceed a certain value , transverse movements lead to a local material pull outs.
- Surface breakdown – Material spallation, below and parallel to the component surface through tribological alternating stress, e.g. periodic application of a high, local load through a counter body (liquid in the case of cavitation).
- Tribo-oxidation (tribo-chemical reaction) – formation of intermediate layers, e.g. oxide layers, after chemical reaction of the contact surfaces with their surroundings (gaseous or liquid media) and their subsequent mechanical destruction.