It was recalled that these alloys exhibited an anomalous peak in the yield stress, at intermediate temperatures, as super-dislocations with a <111> Burgers vector were replaced by dislocations with a <100> Burgers vector. The cause of this change was shown to be a locking of the super-dislocations by the climb of the partials into a non-glissile configuration via a process of local climb that involved point-defect exchange between the partials. Such local climb could occur at temperatures which were lower than those required for general dislocation climb. A detailed examination of the characteristics of the local climb-locking process permitted the evaluation of the effect of external stresses and their orientation, of the strain rate and of the alloy composition upon the locking process; and therefore upon the temperature at which the stress peak and the change in Burgers vector occurred. The predictions were supported by available experimental data over the complete range of Fe-Al alloy compositions.

D.G.Morris: Philosophical Magazine A, 1995, 71[6], 1281-94