Guillaume F. Nataf (Author), Michela Romanini (Author), Eduard Vives (Author), Borut Žužek (Author), Antoni Planes (Author), Jaka Tušek (Author), Xavier Moya (Author)

Abstract

We investigate acoustic emission (AE) that arises during the martensitic transition in a polycrystalline specimen of the prototypical superelastic/elastocaloric alloy Ni 50.4 Ti 49.6 (at. %) driven using tensile strain. We use two independent AE sensors in order to locate AE events, and focus on contributions to the AE that arise away from the grips of the mechanical testing machine. Significant AE activity is present during the first mechanical loading primarily due to nucleation and growth of wide Lüders-like bands during the forward martensitic transition (imaged using visible light and infrared radiation) that lead to persistent changes in intergranular interactions. AE activity is suppressed during the subsequent reverse martensitic transition on unloading, and in successive loading/unloading cycles, for which the Lüders-like bands narrow and modify intergranular interactions to a much smaller extent. After the first loading, we find that the AE activity associated with the martensitic transition is weak, and we suggest that this is because the elastic anisotropy and strain incompatibility in Ni-Ti are low. We also find that the AE activity becomes weaker on mechanical cycling due to increased retained martensite.

Keywords

akustična emisija;martenzitna transformacija;materiali z oblikovnim spominom;elastokalorični učinek;acoustic emission;martensitic transformation;shape memory materials;elastocaloric effect;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FS - Faculty of Mechanical Engineering
UDC: 620.179.17:678.074(045)
COBISS: 31113219 Link will open in a new window
ISSN: 2475-9953
Views: 353
Downloads: 97
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Other data

Secondary language: Slovenian
Secondary keywords: akustična emisija;martenzitna transformacija;materiali z oblikovnim spominom;elastokalorični učinek;
Type (COBISS): Article
Pages: f. 1-9
Volume: ǂVol. ǂ4
Issue: ǂiss. ǂ9
Chronology: Sep. 2020
DOI: 10.1103/PhysRevMaterials.4.093604
ID: 12063378
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