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Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation

[Image: see text] The effect of Nb on the crystal structures and electronic mechanism of martensitic transformation in Ni(50)Ti(50–x)Nb(x) alloys is investigated by first principles. The lattice parameters, the formation energy, the middle eigenvalue of the transformation stretch tensor (λ(2)), and...

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Autores principales: Yang, Xiaolan, Shang, Jiaxiang
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2021
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8412941/
https://www.ncbi.nlm.nih.gov/pubmed/34497897
http://dx.doi.org/10.1021/acsomega.1c02601
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author Yang, Xiaolan
Shang, Jiaxiang
author_facet Yang, Xiaolan
Shang, Jiaxiang
author_sort Yang, Xiaolan
collection PubMed
description [Image: see text] The effect of Nb on the crystal structures and electronic mechanism of martensitic transformation in Ni(50)Ti(50–x)Nb(x) alloys is investigated by first principles. The lattice parameters, the formation energy, the middle eigenvalue of the transformation stretch tensor (λ(2)), and the energy difference between the parent and martensite (ΔE) as a function of Nb content x (x = 0, 2.08, 6.25, 8.33, 10.42, 12.5, 18.75) are calculated. Lattice parameters increase with the increase of Nb content. The formation energies of the parent B2 phase, martensite orthorhombic B19, and monoclinic B19′ increase with the increase of Nb content. It is also found that at ≤10.42 at. % Nb, the martensite stable phase is monoclinic structure B19′; at >10.42 at. % Nb, the orthorhombic crystal structure B19 is formed. The energy difference between the parent and martensite means that the transformation temperature decreases with increasing Nb concentration at Nb ≤ 10.42 at. % and increases at >10.42 at. % Nb. The λ(2) of the NiTiNb alloys have the same value of about 0.95 with low Nb content. Furthermore, the electronic structure mechanisms behind the martensitic transformations are discussed in detail based on the density of states.
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spelling pubmed-84129412021-09-07 Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation Yang, Xiaolan Shang, Jiaxiang ACS Omega [Image: see text] The effect of Nb on the crystal structures and electronic mechanism of martensitic transformation in Ni(50)Ti(50–x)Nb(x) alloys is investigated by first principles. The lattice parameters, the formation energy, the middle eigenvalue of the transformation stretch tensor (λ(2)), and the energy difference between the parent and martensite (ΔE) as a function of Nb content x (x = 0, 2.08, 6.25, 8.33, 10.42, 12.5, 18.75) are calculated. Lattice parameters increase with the increase of Nb content. The formation energies of the parent B2 phase, martensite orthorhombic B19, and monoclinic B19′ increase with the increase of Nb content. It is also found that at ≤10.42 at. % Nb, the martensite stable phase is monoclinic structure B19′; at >10.42 at. % Nb, the orthorhombic crystal structure B19 is formed. The energy difference between the parent and martensite means that the transformation temperature decreases with increasing Nb concentration at Nb ≤ 10.42 at. % and increases at >10.42 at. % Nb. The λ(2) of the NiTiNb alloys have the same value of about 0.95 with low Nb content. Furthermore, the electronic structure mechanisms behind the martensitic transformations are discussed in detail based on the density of states. American Chemical Society 2021-08-19 /pmc/articles/PMC8412941/ /pubmed/34497897 http://dx.doi.org/10.1021/acsomega.1c02601 Text en © 2021 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by-nc-nd/4.0/Permits non-commercial access and re-use, provided that author attribution and integrity are maintained; but does not permit creation of adaptations or other derivative works (https://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Yang, Xiaolan
Shang, Jiaxiang
Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title_full Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title_fullStr Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title_full_unstemmed Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title_short Electronic Mechanism of Martensitic Transformation in Nb-doped NiTi Alloys: A First-Principles Investigation
title_sort electronic mechanism of martensitic transformation in nb-doped niti alloys: a first-principles investigation
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8412941/
https://www.ncbi.nlm.nih.gov/pubmed/34497897
http://dx.doi.org/10.1021/acsomega.1c02601
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