What is Wear

DIN EN ISO 8044 defines wear as the progressive loss of material from the surface of a solid body due to mechanical causes, i. e., contact with solid, liquid, or gaseous bodies and relative motion. Wear is manifested in the presence of loosened particles (wear particles) and in the change in material and shape of the surface layer. Thermal, physical, and chemical processes are activated in the case of most wear processes (triboreactions). Wear is fundamentally caused by mechanically transferred energy. 

If the cause is chemical or electrochemical, wear is corrosion-based. Wear is generally undesirable in engineering because it reduces value. Manufacturing processes that are designed to add value to a workpiece are not referred to as wear [1], 

The perception that friction and wear of materials is not a material property but a system property of the elements involved in the process in conjunction with the combined stresses is widely accepted among system developers. 

The parts and materials directly involved in wear are described as elements of the tribosystem. They characterize the structure of the tribosystem together with their key tribological characteristics and interactions . 

16 Material Selection for Twin Screw Extruder Components [References on page 313] 

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If possible, eliminate inherently weak equipment like sight glasses, hoses, rotameters, bellows, expansion joints, and most plastic equipment. The spare parts consumption from the shop and warehouse will indicate what is wearing out. 

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