Ab initio study of point defects in NiTi-based alloys

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F14%3A00435504" target="_blank" >RIV/68081723:_____/14:00435504 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1103/PhysRevB.89.014110" target="_blank" >http://dx.doi.org/10.1103/PhysRevB.89.014110</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevB.89.014110" target="_blank" >10.1103/PhysRevB.89.014110</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Ab initio study of point defects in NiTi-based alloys

Popis výsledku v původním jazyce

Changes in temperature or stress state may induce reversible B2 <-> (R) <-> B19' martensitic transformations and associated shape memory effects in close-to-stoichiometric nickel-titanium (NiTi) alloys. Recent experimental studies confirmed a considerable impact of the hydrogen-rich aging atmosphere on the subsequent B2 austenite <-> B19' martensite transformation path. In this paper, we employ density functional theory to study properties of Ar, He, and H interstitials in B2 austenite and B19' martensite phases. We show that H interstitials exhibit negative formation energies, while Ar and He interstitials yield positive values. Our theoretical analysis of slightly Ni-rich NiTi-based alloys with the austenite B2 structure shows that a slight over-stoichiometry towards Ni-rich compositions in a range 51-52 at.% is energetically favorable. The same conclusion holds for H-doped NiTi with the H content up to approximate to 6 at.%. In agreement with experimental data we predict H atoms to

Název v anglickém jazyce

Ab initio study of point defects in NiTi-based alloys

Popis výsledku anglicky

Changes in temperature or stress state may induce reversible B2 <-> (R) <-> B19' martensitic transformations and associated shape memory effects in close-to-stoichiometric nickel-titanium (NiTi) alloys. Recent experimental studies confirmed a considerable impact of the hydrogen-rich aging atmosphere on the subsequent B2 austenite <-> B19' martensite transformation path. In this paper, we employ density functional theory to study properties of Ar, He, and H interstitials in B2 austenite and B19' martensite phases. We show that H interstitials exhibit negative formation energies, while Ar and He interstitials yield positive values. Our theoretical analysis of slightly Ni-rich NiTi-based alloys with the austenite B2 structure shows that a slight over-stoichiometry towards Ni-rich compositions in a range 51-52 at.% is energetically favorable. The same conclusion holds for H-doped NiTi with the H content up to approximate to 6 at.%. In agreement with experimental data we predict H atoms to

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

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Projekt

<a href="/cs/project/GA106%2F09%2F1913" target="_blank" >GA106/09/1913: Martenzitické transformace ve slitinách NiTi</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2014

Kód důvěrnosti údajů

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

Název periodika

Physical Review. B

ISSN

1098-0121

e-ISSN

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Svazek periodika

89

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

"Art. No. 014110"

Kód UT WoS článku

000332332300001

EID výsledku v databázi Scopus

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