Annealálás

Annealálás is a heat treatment process used to alter the physical and sometimes chemical properties of a material. The primary goal is typically to reduce hardness, increase ductility, and relieve internal stresses. The process involves heating the material to a specific temperature, holding it there for a period of time, and then cooling it slowly. The rate of cooling is crucial and can significantly influence the final properties. For metals, annealing often results in a more homogeneous and stable microstructure.

The exact temperatures and holding times depend on the material being annealed. For example, annealing steel involves heating it to a temperature above its recrystallization point, allowing new, strain-free grains to form. Annealing glass, on the other hand, aims to remove residual stresses that can form during cooling after manufacturing. This slow cooling prevents the formation of internal fractures. In polymer processing, annealing can improve dimensional stability and mechanical properties by allowing polymer chains to rearrange into a more ordered state. The overall effect is a material that is more workable, less prone to cracking or deformation under stress, and possesses a more uniform internal structure.