Festschweißen

Festschweißen is a German term that translates to "seizing" or "galling" in English, commonly encountered in mechanical engineering and materials science. It describes a type of wear where two surfaces in relative motion adhere to each other, leading to a loss of function and potential damage to the components. This phenomenon typically occurs between similar metals, particularly ductile ones like steel, aluminum, or copper alloys, under conditions of high contact pressure and sliding speed.

The underlying mechanism of Festschweißen involves the transfer of material from one surface to the other. When surfaces are brought into close contact under load, microscopic asperities (high points) on each surface deform and break. Without adequate lubrication or protective coatings, these broken fragments can weld together under the combined pressure and frictional heat. This cold welding process creates localized bonds that resist further relative motion.

Factors contributing to Festschweißen include insufficient lubrication, high surface roughness, high operating temperatures, and the use of incompatible materials. The consequences can range from increased friction and wear to complete seizure of moving parts, such as in bearings, gears, or threaded connections. Prevention strategies involve proper lubrication, surface treatments like nitriding or plating, using dissimilar metals with different hardness or properties, and controlling operating conditions to minimize pressure and temperature. Understanding Festschweißen is crucial for designing reliable and durable mechanical systems.