Kovettuneisuus

Kovettuneisuus is a Finnish term that translates to “hardening” or “rigidity” in English. The word is primarily used in materials science, geology, and polymer chemistry to describe the process or state in which a material becomes harder or more rigid after a chemical, physical, or mechanical transformation.

In metallurgy, kovettuneisuus refers to the hardening of metals through heat treatment processes such as quenching, tempering, or alloying. The phenomenon occurs when the microstructure of the metal changes, typically from a softer to a harder phase, which increases its resistance to deformation. Geologists apply the term to describe the hardening of silicate minerals during metamorphism, where increasing pressure and temperature induce recrystallization and densification of the rock matrix.

Polymer chemists use kovettuneisuus to discuss crosslinking reactions that convert flexible polymer chains into a network that is rigid and heat-resistant. Such crosslinking can be achieved by radiation, chemical initiators, or thermal treatment, and the resulting material often exhibits higher tensile strength and chemical resistance.

The term is also applied, more informally, to describe the stiffening of biological tissues such as tendon or cartilage, where changes in collagen orientation or mineral deposition lead to increased rigidity. In industrial contexts, kovettuneisuus measurements are essential for quality control of building materials, plastics, and aerospace components, ensuring that final products meet specified hardness criteria.