Thermally induced reorientation and plastic deformation of B19' monoclinic martensite in nanocrystalline NiTi wires

0570230 - FZÚ 2024 RIV GB eng J - Journal Article
Iaparova, Elizaveta - Heller, Luděk - Tyc, Ondřej - Šittner, Petr
Thermally induced reorientation and plastic deformation of B19' monoclinic martensite in nanocrystalline NiTi wires.
Acta Materialia. Roč. 242, Jan (2023), č. článku 118477. ISSN 1359-6454. E-ISSN 1873-2453
R&D Projects: GA ČR(CZ) GA20-14114S; GA ČR(CZ) GA22-20181S; GA MŠMT(CZ) EF18_053/0016627; 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 : NiTi * shape memory alloys * martensitic transformation
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 9.4, year: 2022
Method of publishing: Limited access
https://doi.org/10.1016/j.actamat.2022.118477

Functional behavior of nanocrystalline NiTi shape memory wires having various austenitic microstructures was investigated by thermomechanical testing and TEM analysis of martensite microstructures in deformed wires. Three phenomena are reported and discussed in this work. First, martensitic NiTi wire heated under low applied stresses elongates several percent before it shortens during reverse martensitic transformation due to thermally induced martensite reorientation proceeding via motion of interfaces between (001) compound twin domains in the microstructure. Second, martensite stabilization by deformation is not caused by plastic deformation and lattice defects introduced by deformation but that it is due to change of martensite variant microstructures in polycrystal grains during the reorientation process. Finally, generation of unrecovered plastic strains and dislocation defects accompanies all martensitic transformation/reorientation/detwinning processes in NiTi.
Permanent Link: https://hdl.handle.net/11104/0341682