Shape memory effect in nickel-titanium (NiTi) alloys depends on phase transformation between two phases and growth of twin variants in martensite called detwinning. An outstanding issue regarding detwinning in NiTi has been the lack of fundamental understanding of its mechanism at the atomistic level. The present article resolves this issue via first-principles energetics calculations of twin nucleation and growth. Our results based on ion relaxation and valence charge distribution point to a distinct energy barrier during detwinning process and the mechanism is mediated by a complex conjunction of shear and shuffle.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)