NiTi alloy shows superelasticity through:
Superelasticity and shape memory of NiTi alloys is because of phase transformation in their crystal structures when cooled from the stronger, high temperature form (Austenite) to the weaker low temperature form (Martensite).
Conversion from Austenite to Martensite phase
Conversion from Martensite to Austenite phase
M wire phase
Austenite + Martensite + R phase