B2 -> B19' ->B2(T) Martensitic Transformation as a Mechanism of Plastic Deformation of NiTi.

0522366 - ÚJF 2020 RIV US eng C - Conference Paper (international conference)
Šittner, Petr - Heller, Luděk - Sedlák, Petr - Kadeřávek, Lukáš - Chen, Y. - Tyc, Ondřej - Molnárová, Orsolya - Seiner, Hanuš
B2 -> B19' ->B2(T) Martensitic Transformation as a Mechanism of Plastic Deformation of NiTi.
Conference Proceedings from International Conference on Shape Memory and Superelastic Technologies, SMST 2019. Ohio: ASM International, 2019, s. 167-168. ISBN 978-151089272-9.
[International Conference on Shape Memory and Superelastic Technologies 2019, SMST 2019. Konstanz (DE), 13.05.2019-17.05.2019]
R&D Projects: GA MŠMT EF16_013/0001794
Institutional support: RVO:68378271 ; RVO:61389005 ; RVO:61388998
Keywords : materials * stress-induced martensitic transformation * twinning
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Materials engineering (FZU-D); Materials engineering (UT-L)

Deformation of superelastic NiTi wire with tailored microstructure was investigated in tensile loading-unloading tests up to the end of the stress plateau in wide temperature range from room temperature up to 200 degrees C. Lattice defects left in the microstructure of deformed wires were investigated by transmission electron microscopy. Tensile deformation is localized up to the highest test temperatures, even if practically no martensite phase exists in the wire at the end of the stress plateau. In tensile tests at elevated temperatures around 100 degrees C, at which the upper plateau stress approaches the yield stress for plastic deformation of martensite, upper plateau strains become unusually long, transformation strains become unrecoverable and deformation bands containing {114} austenite twins appear in the microstructure of deformed wires.
Permanent Link: http://hdl.handle.net/11104/0306876