抄録
Giant pseudoelasticity of Fe_3Al crystals at room temperature was investigated. Fe-23.0at.%Al single crystals slowly cooled to room temperature at 80K/h demonstrated a recoverable strain of 5%. Moreover, Fe_3Al single crystals isothermally annealed in the D0_3 single phase region showed large pseudoelasticity, compared with that in the bcc or B2 phase regions. Reversible motion of 1/4<111> superpartial dislocations dragging antiphase boundaries led to large pseudoelasticity in Fe_3Al single crystals. It was also found that pseudoelastic behavior of Fe_3Al single crystals was closely related to the ordered domain structure developed in the D0_3 structure. Fe-23.0at.%Al polycrystals showed smaller recovery ratio than the single crystals. Moreover, the recovery ratio of the polycrystals increased with increasing grain size, suggesting that the grain boundaries suppressed the reversible motion of dislocations.
