Temperature dependence of twinning pseudo-elasticity in D03-ordered Fe3Ga single crystals was examined. In the crystals annealed in the D03 single-phase region, 2.2T-type pseudo-twins were frequently introduced during loading at and below room temperature. Since the pseudo-twins had a high energy compared with a perfect twin, the untwinning took place during unloading to decrease their energy resulting in the twinning pseudo-elasticity. Moreover, the twinning pseudo-elasticity became more dominant with decreasing temperature, in contrast to that based on dislocation motion. In particular, high strain recovery during unloading was observed even at -180C. Furthermore, the formation and annihilation stresses of the pseudo-twins were almost constant irrespective of deformation temperature at and below 100C. This means that high driving force for the twinning pseudo-elasticity was preserved even at low temperatures.

Temperature Dependence of Twinning Pseudoelasticity in Fe3Ga Single Crystals. H.Y.Yasuda, T.Kishimoto, Y.Umakoshi: Materials Transactions, 2010, 51[12], 2196-200