Evolution of internal stresses during cyclic superelastic deformation of NiTi investigated by X-ray synchrotron diffraction

0456634 - FZÚ 2016 RIV NL eng C - Conference Paper (international conference)
Sedmák, P. - Šittner, Petr - Pilch, Jan - Curfs, C.
Evolution of internal stresses during cyclic superelastic deformation of NiTi investigated by X-ray synchrotron diffraction.
Materials Today: Proceedings ICOMAT 2014. Amsterdam: Elsevier Ltd, 2015 - (San Juan, J.; López-Echarri, A.; Nó, M.; López, G.), s. 731-734. 2. ISSN 2214-7853.
[International Conference on Martensitic Transformations ICOMAT 2014. Bilbao (ES), 06.07.2014-11.07.2014]
R&D Projects: GA ČR GPP108/12/P111; GA ČR GA14-15264S; GA ČR GAP107/12/0800
Institutional support: RVO:68378271
Keywords : shape memory alloy * NiTi * martensitic transformation * cyclic deformation * x-ray diffraction
Subject RIV: JG - Metallurgy

Cyclic tensile superelastic deformation of NiTi was investigated using high resolution in-situ synchrotron x-ray diffraction method. Diffraction patterns were recorded under applied stress prior and after the stress induced martensitic transformation, analyzed and interpreted in view of the evolution of microstructure in the transforming polycrystal. A simple bicrystal scheme of the polycrystal transformation is used to rationalize the experimental evidence on microstructure evolution during cycling. It is claimed that the instability of cyclic superelastic response of NiTi is due to the gradual rise of internal stresses originating from the accumulation of plastic deformation accompanying the martensitic transformation in constrained polycrystalline environment.
Permanent Link: http://hdl.handle.net/11104/0257141