Impact of hydrogen-assisted heat treatments on microstructure and transformation path in a Ni-rich NiTi shape memory alloy

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F13%3A00107100" target="_blank" >RIV/00216224:14310/13:00107100 - isvavai.cz</a>

Alternative codes found

RIV/68081723:_____/13:00421756

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0925838812013138" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0925838812013138</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2012.07.096" target="_blank" >10.1016/j.jallcom.2012.07.096</a>

Result language

angličtina

Original language name

Impact of hydrogen-assisted heat treatments on microstructure and transformation path in a Ni-rich NiTi shape memory alloy

Original language description

We report results of differential scanning calorimetry and transmission electron microscopy experiments in which martensitic transformations and microstructure of Ti-50.9 at%Ni shape memory samples were investigated after heat treatments in controlled gaseous environments. The heat treatments were performed in mixtures consisting of hydrogen and helium with an overall pressure of 900 mbar. The cylindrical samples were heat treated either in a Regime I (850 degrees C/1800 s/WQ) or in a Regime II (the Regime I plus 450 degrees C/3600 s/WQ). DSC charts clearly document that the B2 -&gt; B19' or R -&gt; B19' martensitic phase transitions diminish after Regime I and Regime II treatments with increasing partial pressure of hydrogen. We show that the hydrogen rich environments do not cause variations in size and density of Ni4Ti3 particles. Conversely, the Regime I heat treatments assisted by hydrogen result in 1/2 (111)(B2) diffuse intensity maxima in selected area electron diffraction patterns. These maxima were not observed after heat treatments in hydrogen deficient atmospheres. Therefore, we suggest that the gradual suppression of the martensitic transformation may be related to either chemical and/or strain modulations of the B2 lattice triggered by the presence of interstitial hydrogen atoms.

Czech name

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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

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2013

Confidentiality

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

Name of the periodical

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Volume of the periodical

577

Issue of the periodical within the volume

NOV

Country of publishing house

CH - SWITZERLAND

Number of pages

4

Pages from-to

„S287“-„S290“

UT code for WoS article

000329891400061

EID of the result in the Scopus database

2-s2.0-84891629493