On fleischer's potential for tetragonal interaction

Abstract

The force—distance relation for a glide dislocation interacting with a local tetragonal distortion has been calculated by Fleischer. A particular form of stress-dependence of the activation energy and of the activation volume is generally assumed to follow from this calculation. The original derivation assumes a second force—distance function, said to approximate the exact calculation in the working stress range, and a constant length of dislocation segment. Both assumptions are criticized here. A new force—distance function is proposed, which is an improved approximation of the tetragonal interaction. Taking account of the stress—dependence of segment length, it leads fortuitously to the same form of stress-dependence for activation parameters as the earlier calculation and is in better agreement with experiment.