Dislokatsioonijoonele

Dislokatsioonijoonele (dislocation line) is a one-dimensional defect in a crystal lattice that marks a region where the orderly arrangement of atoms is disrupted along a line. It represents the end point of an extra half-plane of atoms (edge dislocation) or the twist of the lattice around a line (screw dislocation), or a combination of both (mixed dislocation). Dislocations are intrinsic to real crystals, where perfect lattices are never achieved.

Dislocations are central to crystal plasticity because they enable plastic deformation to occur at stresses much lower than would be required for a perfect crystal to shear all at once. The lattice distortion associated with a dislocation is described by the Burgers vector, which characterizes the magnitude and direction of the shift in the lattice. The energy of a dislocation line depends on material properties such as the shear modulus and the Burgers vector, and it can be influenced by interactions with other dislocations, solute atoms, and precipitates.

Movement of dislocation lines under applied stress occurs mainly by glide along slip planes or by climb through diffusion at higher temperatures. The mobility of dislocations is affected by temperature, alloying, and the presence of obstacles that pin the line, leading to phenomena such as work hardening and fatigue. Dislocations can interact, multiply, or annihilate, and their configuration—density and arrangement—strongly influences mechanical behavior.

Observation and study of dislocation lines employ methods such as transmission electron microscopy, X-ray diffraction, and etch-pit techniques. Understanding dislocation lines is fundamental to predicting and engineering the mechanical performance of crystalline materials, including metals and semiconductors.