Direct measurement of the variation in the energy of a dislocation locked in specific orientations

A general method is presented based on transmission electron microscopy observations of the segmented shape of dislocations under stress for measuring the decrease in dislocations’ self-energy when they are locked in specific orientations. The general formulation is given for any direction of locking in any material, and the method is exemplified in the case of the hexagonal phases of an industrially important Ti-based alloy, where a significant in-core rearrangement reduces the energy of screw dislocations by ∼16%.