dislokationsskog

Dislokationsskog, literally “dislocation forest,” is a term used in crystallography and materials science to describe a dense network of dislocations within a crystalline solid. The concept evokes a tree-like, interconnected arrangement of line defects that can span regions of a crystal, particularly after significant plastic deformation.

Formation and structure: Dislocations are line defects that enable plastic deformation as they glide along slip planes. Under mechanical work, new dislocations are generated and existing ones accumulate, interact, and form junctions. In heavily deformed zones, these dislocations organize into a complex network on multiple slip systems. Grain boundaries often act as sinks or sources, influencing the density and arrangement of the forest.

Mechanical consequences: A dislokationsskog hinders further dislocation motion and contributes to work hardening, increasing the yield stress and often reducing ductility. The forest affects properties such as strength, toughness, and fatigue resistance. Recovery and recrystallization processes can reduce forest density, partially restoring ductility and altering mechanical behavior.

Characterization and modeling: The forest is studied with transmission electron microscopy and diffraction techniques; dislocation density is a key parameter for describing its extent. The Taylor relation links flow stress to the square root of dislocation density, and dislocation dynamics simulations are used to explore forest formation, interactions, and evolution under different loading paths.

Terminology and context: In Swedish-language literature, dislokationsskog describes a high-density, interconnected network of dislocations within a metal crystal. The concept is particularly relevant to metals and alloys subjected to plastic deformation through processes such as rolling, drawing, or forging, where controlling forest density influences mechanical performance.