Single crystals of the D03 long-range ordered intermetallic compound were compression-tested at 213 to 493K. The orientations of the crystals covered the entire standard triangle. All of them were pseudoelastic at lower temperatures. During unloading, an appreciable fraction of the plastic deformation was recovered. At the above temperatures, the yield strength and the fraction of strain which was recovered during unloading decreased as the temperature was increased. Transmission electron microscopy revealed that these decreases were caused by a change in the dislocation processes. At lower temperatures, there existed very widely-spaced partial dislocations with Burgers vectors of (a/4)<111>-type. At higher temperatures, 4 such partial dislocations glided together to form a perfect dislocation. At the higher temperatures, crystals which had the [¯111] orientation exhibited a different behaviour. That is, single (a/4)<111> partials created narrow slip-bands by gliding on closely-spaced planes. The experimental results were tentatively explained in terms of the differing temperature dependences of the frictional stresses and cross-slip probabilities.

Pseudoelasticity in Fe3Al Single Crystals. E.Langmaack, E.Nembach: Philosophical Magazine A, 1999, 79[10], 2359-77