Beyond the strain recoverability of martensitic transformation in NiTi

0517366 - FZÚ 2020 RIV GB eng J - Journal Article
Heller, Luděk - Šittner, Petr - Sedlák, Petr - Seiner, Hanuš - Tyc, Ondřej - Kadeřávek, Lukáš - Sedmák, P. - Vronka, Marek
Beyond the strain recoverability of martensitic transformation in NiTi.
International Journal of Plasticity. Roč. 116, May (2019), s. 232-264. ISSN 0749-6419. E-ISSN 1879-2154
R&D Projects: GA ČR GA16-20264S; GA ČR GA18-03834S; GA MŠMT(CZ) LM2015088; GA MŠMT LM2015087
Institutional support: RVO:68378271 ; RVO:61388998
Keywords : shape-memory alloys * plastic-deformation * NiTi * mechanics modelling * TRIP * tensile testing
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Materials engineering (UT-L)
Impact factor: 6.490, year: 2019
Method of publishing: Limited access
https://doi.org/10.1016/j.ijplas.2019.01.007

Tensile deformation of a medical grade NiTi wire was investigated in a wide temperature range from −100 °C to 450 °C. Supplemental in-situ electrical resistance, synchrotron x-ray diffraction, digital image correlation and ex-situ TEM methods were employed to characterize deformation/transformation processes acting at high temperatures and stresses. Conventional superelastic deformation due to stress induced martensitic transformation taking place around room temperature becomes gradually accompanied by dislocation slip in the temperature range 30–80 °C. With further increasing temperature, stress induced martensitic transformation still proceeds in localized manner but the length of the forward stress plateau increases, volume fraction of the martensite phase at the end of forward stress plateau decreases, unrecovered strain increases and {114} austenite twins appeared in the microstructure of deformed wires.
Permanent Link: http://hdl.handle.net/11104/0302698