High resolution determination of the core structure of 1/3⟨1120⟩ {1010} edge dislocation in titanium

Abstract

The core structure of edge dislocations produced during the prismatic slip mode in α-titanium has been determined by high resolution electron microscopy. The core was extended in the prismatic plane with a width equal to 12 Å. Irrespective of the exact dissocation scheme, this gives a stacking fault energy close to 150 ergs cm⁻². There are experimental indications in favour of the dissociation scheme proposed by Tyson (1967), but they have to be confirmed by a different method. The present results indicate that small dissociations are also possible for screws and could explain the particular behaviour of the critical resolved shear stress.