verfestigung

Verfestigung is a term used in materials science and metallurgy to describe the increase in strength and hardness of a material, typically as a result of plastic deformation. In metals, it is most commonly associated with cold working, where processes such as drawing, rolling, or bending introduce a high density of dislocations. The interactions among these dislocations hinder their motion, raising the yield strength and the stress required for further deformation. This often comes at the cost of reduced ductility and toughness.

Other mechanisms can contribute to Verfestigung, including substructure formation (dislocation walls and cells), grain refinement, and precipitation hardening (age hardening). Warm or dynamic conditions can modify the effect: at higher temperatures, recovery or recrystallization may reduce or reverse part of the hardening.

Verfestigung is also observed in polymers and some ceramics to a lesser extent. In polymers, chain alignment or increased cross-linking during processing can raise modulus and hardness, while in metals the most significant strengthening usually results from dislocation mechanisms and, in some cases, second-phase precipitation.

Practically, Verfestigung is used to tailor mechanical properties for specific applications, for example in wires or metal sheets where higher strength is desired. It is often followed by annealing, tempering, or anneal cycles to restore ductility if needed. Measurement of hardening is typically done via hardness tests and tensile tests, which reveal increased yield and tensile strengths alongside potential decreases in elongation at break.