Verhärten

Verhärten is a German verb meaning to become harder or to cause something to harden. It is used across disciplines to describe a transition from a softer or more pliable state to a firmer one, and in some contexts to refer to a deliberate processing step.

In materials science and engineering, Verhärtung describes processes that increase material hardness. Common mechanisms include work hardening (Kaltverfestigung), where plastic deformation raises dislocation density; heat treatments such as quenching and tempering, which alter the microstructure to improve hardness; and surface-hardening methods like carburizing or nitriding for increased wear resistance. Polymers may harden through curing or cross-linking, often triggered by heat, catalysts, or radiation. The result is typically higher hardness and strength, sometimes at the expense of toughness or ductility.

In medicine and biology, Verhärtung refers to stiffening of tissues. Fibrosis and sclerosis are forms of pathological Verhärtung. For example, arteriosclerosis denotes hardening and loss of elasticity of arteries, while scleroderma involves hardening of skin and connective tissue. Plants can also undergo Verhärtung when tissues lignify or sclerify, increasing rigidity.

The term is general and appears in technical and clinical contexts, often combined with the subject, e.g., Verhärtung des Materials, Verhärtung der Arterien. Understanding the underlying mechanism—dislocations, phase transformations, cross-linking, or fibrosis—helps explain the consequences for performance, health, or growth.