In Situ Characterization of the Elasticity and Stress-Induced Phase Transformation of NiTi Shape-Memory Alloy

0499131 - ÚJF 2019 RIV PL eng J - Journal Article
Grabec, Tomáš - Zoubková, K. - Stoklasová, Pavla - Ševčík, Martin - Sedlák, Petr - Janovská, Michaela - Seiner, Hanuš - Landa, Michal
In Situ Characterization of the Elasticity and Stress-Induced Phase Transformation of NiTi Shape-Memory Alloy.
Acta Physica Polonica A. Roč. 134, č. 3 (2018), s. 811-814. ISSN 0587-4246. E-ISSN 1898-794X.
[14th International Symposium on Physics of Materials (ISPMA). Prague, 10.09.2017-15.09.2017]
R&D Projects: GA MŠMT EF16_013/0001794; GA ČR GB14-36566G
Institutional support: RVO:61388998 ; RVO:61389005
Keywords : polycrystalline shape memory alloy * NiTi * Ritz-Rayleigh based method
OECD category: Nuclear related engineering; Acoustics (UT-L)
Impact factor: 0.545, year: 2018

In the presented paper, a sample of polycrystalline shape-memory NiTi alloy is studied under compression up to 5% by the means of laser-excited and laser-detected ultrasound waves. The evolution of a propagation velocity of the surface acoustic wave is measured in situ during mechanical loading. An inverse method based on the Ritz-Rayleigh numerical approach is then used to obtain the development of elastic properties of the sample. This process enables an analysis of the evolution of stress-induced transformation from the austenitic to the martensitic phase with the possibility to describe several stages of such transformation, i.e., the transformation to full R-phase, its reorientation causing strong anisotropy of the polycrystalline sample, and consecutive gradual transition to martensite.
Permanent Link: http://hdl.handle.net/11104/0291400