Beyond the strain recoverability of martensitic transformation in NiTi

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F19%3A00504077" target="_blank" >RIV/61389005:_____/19:00504077 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/68378271:_____/19:00517366 RIV/61388998:_____/19:00517366 RIV/68407700:21340/19:00337181

Výsledek na webu

<a href="https://doi.org/10.1016/j.ijplas.2019.01.007" target="_blank" >https://doi.org/10.1016/j.ijplas.2019.01.007</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.ijplas.2019.01.007" target="_blank" >10.1016/j.ijplas.2019.01.007</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Beyond the strain recoverability of martensitic transformation in NiTi

Popis výsledku v původním jazyce

Tensile deformation of a medical grade NiTi wire was investigated in a wide temperature range from -100 degrees C to 450 degrees C. Supplemental in-situ electrical resistance, synchrotron x-ray diffraction, digital image correlation and ex-situ TEM methods were employed to characterize deformation/transformation processes acting at high temperatures and stresses. Conventional superelastic deformation due to stress induced martensitic transformation taking place around room temperature becomes gradually accompanied by dislocation slip in the temperature range 30-80 degrees C. With further increasing temperature, stress induced martensitic transformation still proceeds in localized manner but the length of the forward stress plateau increases, volume fraction of the martensite phase at the end of forward stress plateau decreases, unrecovered strain increases and {114} austenite twins appeared in the microstructure of deformed wires. These observations were explained by the activity of a new deformation mechanism - stress induced B2 = > B19' = > B2(T) martensitic transformation into twinned austenite coupled with dislocation slip. Thermodynamic and crystallographic aspects of this B2 = > B19' = > B2(T) martensitic transformation breaking the strain recoverability limit of cubic to monoclinic martensitic transformation were outlined. To rationalize the observed thermomechanical responses of the wire at elevated temperatures, a TRIP like deformation mechanism based on this transformation was incorporated into an existing constitutive model of thermomechanical behaviors of NiTi. The model was numerically implemented into finite element code, simulations were performed and compared with the experimentally observed behaviors.

Název v anglickém jazyce

Beyond the strain recoverability of martensitic transformation in NiTi

Popis výsledku anglicky

Tensile deformation of a medical grade NiTi wire was investigated in a wide temperature range from -100 degrees C to 450 degrees C. Supplemental in-situ electrical resistance, synchrotron x-ray diffraction, digital image correlation and ex-situ TEM methods were employed to characterize deformation/transformation processes acting at high temperatures and stresses. Conventional superelastic deformation due to stress induced martensitic transformation taking place around room temperature becomes gradually accompanied by dislocation slip in the temperature range 30-80 degrees C. With further increasing temperature, stress induced martensitic transformation still proceeds in localized manner but the length of the forward stress plateau increases, volume fraction of the martensite phase at the end of forward stress plateau decreases, unrecovered strain increases and {114} austenite twins appeared in the microstructure of deformed wires. These observations were explained by the activity of a new deformation mechanism - stress induced B2 = > B19' = > B2(T) martensitic transformation into twinned austenite coupled with dislocation slip. Thermodynamic and crystallographic aspects of this B2 = > B19' = > B2(T) martensitic transformation breaking the strain recoverability limit of cubic to monoclinic martensitic transformation were outlined. To rationalize the observed thermomechanical responses of the wire at elevated temperatures, a TRIP like deformation mechanism based on this transformation was incorporated into an existing constitutive model of thermomechanical behaviors of NiTi. The model was numerically implemented into finite element code, simulations were performed and compared with the experimentally observed behaviors.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2019

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

International Journal of Plasticity

ISSN

0749-6419

e-ISSN

—

Svazek periodika

116

Číslo periodika v rámci svazku

5

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

33

Strana od-do

232-264

Kód UT WoS článku

000463303400013

EID výsledku v databázi Scopus

2-s2.0-85062169868