lõõmutatud

Lõõmutatud is an Estonian word that translates to "tempered" in English. It primarily refers to a process of heat treatment applied to materials, most commonly metals and glass, to improve their properties. This process involves heating the material to a specific temperature and then cooling it in a controlled manner. The precise temperatures and cooling rates depend on the material being treated and the desired outcome.

In metallurgy, tempering is typically performed after hardening. Hardening makes a metal strong and brittle by rapidly cooling it from a high temperature. Tempering reduces this brittleness, making the metal tougher and more durable while retaining a significant portion of its hardness. The process involves heating the hardened metal to a temperature below its critical point and then allowing it to cool slowly. Different tempering temperatures result in different combinations of hardness and toughness.

For glass, tempering, also known as toughening, is a safety measure. It involves heating the glass to a high temperature, close to its softening point, and then rapidly cooling its surfaces with jets of air. This creates internal stresses within the glass: the surfaces are in compression, while the interior is in tension. When tempered glass breaks, it fractures into small, relatively harmless granular pieces instead of sharp shards, significantly reducing the risk of injury. This makes it ideal for applications where safety is paramount, such as in vehicle windows and shower doors. The term "lõõmutatud" encompasses both these applications of controlled heat treatment.