Localized plastic deformation of superelastic NiTi wires in tension

0574356 - FZÚ 2024 RIV CH eng J - Journal Article
Kadeřávek, Lukáš - Šittner, Petr - Molnárová, Orsolya - Klimša, Ladislav - Heller, Luděk
Localized plastic deformation of superelastic NiTi wires in tension.
Shape Memory and Superelasticity. Roč. 9, June (2023), s. 261-279. ISSN 2199-384X. E-ISSN 2199-3858
R&D Projects: GA ČR(CZ) GA20-14114S; GA ČR(CZ) GA22-20181S; GA MŠMT(CZ) EF16_019/0000760
Grant - others:OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Research Infrastructure: CzechNanoLab - 90110; CzechNanoLab II - 90251
Institutional support: RVO:68378271
Keywords : martensite * NiTi materials * stress–strain * twinning * slip
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 2.2, year: 2022
Method of publishing: Open access

Tensile deformation of superelastic NiTi shape memory alloy wires at temperatures above austenite finish temperature proceeds via stress-induced martensitic transformation followed by plastic deformation of oriented martensite. While superelastic deformation tends to proceed in localized manner, plastic deformation of martensite is considered to be homogeneous. In this work, we have investigated strain localization patterns in tensile tests on superelastic NiTi wires deformed until fracture in wide temperature range from 10 to 400 °C using in situ digital image correlation analysis of local strains and analyzed lattice defects created during the deformation in TEM. We have found that plastic deformation of oriented martensite can be either homogeneous or localized, depending on the yield stress and strain hardening rate (on the Considere criterion for stability of tensile deformation).
Permanent Link: https://hdl.handle.net/11104/0344695