Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi

In this work, effects of temperature and microstructure on tensile behavior of superelastic NiTi wires were analyzed. We analyzed cold-drawn NiTi wires of 1.78 mm that received four different final heat treatments using short direct electrical current pulses. Final coarse-grained microstructures ran...

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Main Authors: E. Alarcon, L. Heller, E. de Prado, J. Kopeček
Format: Article
Language:English
Published: Elsevier 2023-02-01
Series:Materials & Design
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S0264127523000321
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author E. Alarcon
L. Heller
E. de Prado
J. Kopeček
author_facet E. Alarcon
L. Heller
E. de Prado
J. Kopeček
author_sort E. Alarcon
collection DOAJ
description In this work, effects of temperature and microstructure on tensile behavior of superelastic NiTi wires were analyzed. We analyzed cold-drawn NiTi wires of 1.78 mm that received four different final heat treatments using short direct electrical current pulses. Final coarse-grained microstructures ranged from recovered up to fully recrystallized microstructure with grain size of 25 µm. Effects of temperature in the range 30–130 °C were analyzed using monotonous tensile tests where a temperature gradient was induced along the sample axis. Deformation processes related to martensitic transformation and plastic deformation were characterized by temperature resolved stress–strain responses, deformation work, released heat, volume fraction of martensite. Deformation-induced microstructure changes were analyzed post-mortem using Electron Backscatter Diffraction and x-ray diffraction. Except the least recovered microstructure, the samples did not follow linear temperature trends according to Clausius-Clapeyron. With increasing temperature, the plateau stress of localized martensitic transformation stabilized at a constant stress while volume fraction of martensite decreased down to zero. Localized strains induced by martensitic transformation and ductility evolved non-monotonously with temperature, reaching maxima at temperatures that decreased with increasing microstructure recovery or recrystallization. Large ductility was positively correlated with occurrence of austenite deformation twins in deformed microstructure.
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spelling doaj.art-c427c32f27b24f6fbf04d377ef756ac42023-03-08T04:13:32ZengElsevierMaterials & Design0264-12752023-02-01226111617Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTiE. Alarcon0L. Heller1E. de Prado2J. Kopeček3Institute of Physics of the Czech Academy of Sciences, Na Slovance 1992/2, 18221 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Na Slovance 1992/2, 18221 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Na Slovance 1992/2, 18221 Prague, Czech RepublicInstitute of Physics of the Czech Academy of Sciences, Na Slovance 1992/2, 18221 Prague, Czech RepublicIn this work, effects of temperature and microstructure on tensile behavior of superelastic NiTi wires were analyzed. We analyzed cold-drawn NiTi wires of 1.78 mm that received four different final heat treatments using short direct electrical current pulses. Final coarse-grained microstructures ranged from recovered up to fully recrystallized microstructure with grain size of 25 µm. Effects of temperature in the range 30–130 °C were analyzed using monotonous tensile tests where a temperature gradient was induced along the sample axis. Deformation processes related to martensitic transformation and plastic deformation were characterized by temperature resolved stress–strain responses, deformation work, released heat, volume fraction of martensite. Deformation-induced microstructure changes were analyzed post-mortem using Electron Backscatter Diffraction and x-ray diffraction. Except the least recovered microstructure, the samples did not follow linear temperature trends according to Clausius-Clapeyron. With increasing temperature, the plateau stress of localized martensitic transformation stabilized at a constant stress while volume fraction of martensite decreased down to zero. Localized strains induced by martensitic transformation and ductility evolved non-monotonously with temperature, reaching maxima at temperatures that decreased with increasing microstructure recovery or recrystallization. Large ductility was positively correlated with occurrence of austenite deformation twins in deformed microstructure.http://www.sciencedirect.com/science/article/pii/S0264127523000321Martensitic transformationShape memory alloysSuperelasticityDeformation twinningNiTiMicrostructure
spellingShingle E. Alarcon
L. Heller
E. de Prado
J. Kopeček
Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
Materials & Design
Martensitic transformation
Shape memory alloys
Superelasticity
Deformation twinning
NiTi
Microstructure
title Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
title_full Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
title_fullStr Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
title_full_unstemmed Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
title_short Temperature and microstructure dependent tensile behavior of coarse grained superelastic NiTi
title_sort temperature and microstructure dependent tensile behavior of coarse grained superelastic niti
topic Martensitic transformation
Shape memory alloys
Superelasticity
Deformation twinning
NiTi
Microstructure
url http://www.sciencedirect.com/science/article/pii/S0264127523000321
work_keys_str_mv AT ealarcon temperatureandmicrostructuredependenttensilebehaviorofcoarsegrainedsuperelasticniti
AT lheller temperatureandmicrostructuredependenttensilebehaviorofcoarsegrainedsuperelasticniti
AT edeprado temperatureandmicrostructuredependenttensilebehaviorofcoarsegrainedsuperelasticniti
AT jkopecek temperatureandmicrostructuredependenttensilebehaviorofcoarsegrainedsuperelasticniti