A

Super-elastic NiTi undergoes stress-induced martensitic transformation, giving it a much larger elastic range and ability to return to its original shape after deflection; non-super-elastic (thermo-active or conventional) NiTi lacks this plateau and shows earlier permanent deformation, so its spring-back is smaller [Bartzela et al., 2007, PMID 18004922; Gatto et al., 2013, PMID 22023884].