In-situ synchrotron x-ray diffraction texture analysis of tensile deformation of nanocrystalline superelastic NiTi wire at various temperatures

0563684 - FZÚ 2023 RIV CH eng J - Článek v odborném periodiku
Bian, Xiaohui - Heller, Luděk - Tyc, Ondřej - Kadeřávek, Lukáš - Šittner, Petr
In-situ synchrotron x-ray diffraction texture analysis of tensile deformation of nanocrystalline superelastic NiTi wire at various temperatures.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 853, Sep (2022), č. článku 143725. ISSN 0921-5093. E-ISSN 1873-4936
Grant CEP: GA MŠMT(CZ) EF16_019/0000760; GA ČR(CZ) GA22-20181S; GA ČR(CZ) GA20-14114S; GA MŠMT LM2018110
Grant ostatní: OP VVV - SOLID21(XE) CZ.02.1.01/0.0/0.0/16_019/0000760
Institucionální podpora: RVO:68378271
Klíčová slova: martensitic transformatio * shape memory alloy * NiTi * texture * synchrotron x-ray diffraction * tensile test * twinning
Obor OECD: Materials engineering
Impakt faktor: 6.4, rok: 2022
Způsob publikování: Omezený přístup
https://doi.org/10.1016/j.msea.2022.143725

According to the state-of-the-art view, superelastic deformation of NiTi wires at room temperature proceeds via stress induced martensitic transformation from B2 cubic austenite to B19'monoclinic martensite. With increasing test temperature, the stress induced martensitic transformation is substituted by plastic deformation of austenite at martensite desist temperature M-D. However, there are many unsolved problems with this widely accepted view. What are the texture and martensite variant microstructure in stress induced martensite and do they depend on test temperature? Does the austenite transform to martensite completely within the transformation plateau range? How the superelasticity changes into plastic deformation of austenite with increasing temperature is it stepwise or gradual change? How the wire deforms plastically at various temperatures? Does plastic deformation occur in austenite or in martensite, via dislocation slip or deformation twinning? Are the deformation/transformation processes in nanocrystalline NiTi wires same as in large grain polycrystals? We have addressed these long standing but unsolved questions by performing series of in-situ synchrotron x-ray diffraction experiments on superelastic nanocrystalline NiTi wire subjected to tensile tests at 20, 90 and 150 degrees C until fracture supplemented by post mortem TEM analysis of lattice defects created by the tensile deformation.
Trvalý link: https://hdl.handle.net/11104/0335562