Lattice Defects Generated by Cyclic Thermomechanical Loading of Superelastic NiTi Wire

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61389005%3A_____%2F21%3A00541796" target="_blank" >RIV/61389005:_____/21:00541796 - isvavai.cz</a>

Alternative codes found

RIV/68378271:_____/21:00563592 RIV/68407700:21340/21:00362709

Result on the web

<a href="https://doi.org/10.1007/s40830-021-00315-4" target="_blank" >https://doi.org/10.1007/s40830-021-00315-4</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s40830-021-00315-4" target="_blank" >10.1007/s40830-021-00315-4</a>

Result language

angličtina

Original language name

Lattice Defects Generated by Cyclic Thermomechanical Loading of Superelastic NiTi Wire

Original language description

Cyclic instability of stress-strain-temperature functional responses of NiTi is presumably due to the plastic deformation accompanying martensitic transformation proceeding under external stress. In order to obtain systematic experimental evidence on this, we have performed series of cyclic thermomechanical loading tests (10 cycles) on superelastic NiTi wires with nanocrystalline microstructure, evaluated accumulated unrecovered strains and analysed permanent lattice defects created during the cycling by TEM. The accumulated unrecovered strains and density of lattice defects increased with increasing temperature and stress, at which the forward and/or reverse transformation proceeded. It did not correlate with the temperature and stress applied in the test as such. If the martensitic transformation proceeded at low stress (<100 MPa), the cyclic stress-strain-temperature responses of the wire were found to be almost stable (only marginal accumulated unrecovered strain and few isolated dislocation loops and segments were generated during the thermomechanical cycling). This was the case in thermal cycling at low stresses or in cyclic shape memory test. If the forward and/or reverse martensitic transformation proceeded under large external stress (>250 MPa), the responses were very unstable (large accumulated unrecovered strains and high density of dislocations and deformation bands). A scheme allowing for estimating the cyclic instability of functional behaviours of various NiTi wires in wide range of thermomechanical loading tests was introduced.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

20501 - Materials engineering

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

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

Name of the periodical

Shape Memory and Superelasticity

ISSN

2199-384X

e-ISSN

2199-3858

Volume of the periodical

7

Issue of the periodical within the volume

MAR

Country of publishing house

CH - SWITZERLAND

Number of pages

24

Pages from-to

65-88

UT code for WoS article

000634670200002

EID of the result in the Scopus database

2-s2.0-85103429720