Ab initio prediction of phase stability of martensitic structures in binary NiTi under hydrostatic tension

Sam Bakhtiari, Jefferson Zhe Liu, Bashir S. Shariat, Yinong Liu, Hong Yang

Research output: Contribution to journalArticle

Abstract

Near-equiatomic NiTi is known to exhibit multiple martensitic allotropes, including B19′, B19″ and base-centred orthorhombic (BCO). Formation of these martensites is associated with volume expansions, thus hydrostatic loading has direct influence on the stability, ground-state, transformation pathways and the structures of these phases. This work was conducted to clarify some uncertainties in the literature concerning the effect of hydrostatic tension on these properties of the martensite allotropes using the generalised solid-state nudge elastic band method implemented in density functional theory. It was found that higher hydrostatic compression favours phases of lower specific volumes, and higher hydrostatic tension favours phases of higher specific volumes. B19′ is stable at above 2 GPa compression, B19″ is stable within -6 GPa tension and 6.6 GPa compression and BCO is stable between -8 GPa tension and 8.8 GPa compression.

Original languageEnglish
Article number035701
JournalPhysica Scripta
Volume95
Issue number3
DOIs
Publication statusPublished - 7 Feb 2020

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