Shape memory behavior in ductility enhanced Ni-Al-Fe-Mn alloys

摘要

Fe, Mn alloying effects on the shape memorybehavior in two phases NiAl base shape memory alloys have beeninvestigated. The γ phase formed by the alloying Fe or Fe+Mnaffected drastically not only on the hot workability but also on thetensile ductility of these alloys at room temperature. The transfor-mation temperature increased with increase in annealingtemperature because of the change in composition of the β matrix.Martensite transformation temperature γ of the alloys annealed at1300°C was above 150°C . And the shape recovery ratio of thealloys is about 70%. Since a part of shape recovery energy of β(β')phase was consumed on shape recovery of y phase plasticallydeformed, the less γ phase, the better shape memory effect.Therefore these results mean that NiAl alloys with Fe or Fe+Mnare potential shape memory alloys for applications above thetemperature of 150°C .