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Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy

Recent studies indicate that eutectic high-entropy alloys can simultaneously possess high strength and high ductility, which have potential industrial applications. The present study focuses on Al(0.7)CoCrFeNi, a lamellar dual-phase (fcc + B2) precipitation-strengthenable eutectic high entropy alloy...

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Detalles Bibliográficos
Autores principales: Gwalani, Bharat, Gangireddy, Sindhura, Zheng, Yufeng, Soni, Vishal, Mishra, Rajiv S., Banerjee, Rajarshi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6478865/
https://www.ncbi.nlm.nih.gov/pubmed/31015578
http://dx.doi.org/10.1038/s41598-019-42870-y
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author Gwalani, Bharat
Gangireddy, Sindhura
Zheng, Yufeng
Soni, Vishal
Mishra, Rajiv S.
Banerjee, Rajarshi
author_facet Gwalani, Bharat
Gangireddy, Sindhura
Zheng, Yufeng
Soni, Vishal
Mishra, Rajiv S.
Banerjee, Rajarshi
author_sort Gwalani, Bharat
collection PubMed
description Recent studies indicate that eutectic high-entropy alloys can simultaneously possess high strength and high ductility, which have potential industrial applications. The present study focuses on Al(0.7)CoCrFeNi, a lamellar dual-phase (fcc + B2) precipitation-strengthenable eutectic high entropy alloy. This alloy exhibits an fcc + B2 (B2 with bcc nano-precipitates) microstructure resulting in a combination of the soft and ductile fcc phase together with hard B2 phase. Low temperature annealing leads to the precipitation of ordered L1(2) intermetallic precipitates within the fcc resulting in enhanced strength. The strengthening contribution due to fine scale L1(2) is modeled using Orowan dislocation bowing and by-pass mechanism. The alloy was tested under quasi-static (strain-rate = 10(−3) s(−1)) tensile loading and dynamic (strain-rate = 10(3) s(−1)) compressive loading. Due to the fine lamellar microstructure with a large number of fcc-bcc interfaces, the alloy show relatively high flow-stresses, ~1400 MPa under quasi-static loading and in excess of 1800 MPa under dynamic loading. Interestingly, the coherent nano-scale L1(2) precipitate caused a significant rise in the yield strength, without affecting the strain rate sensitivity (SRS) significantly. These lamellar structures had higher work hardening due to their capability for easily storing higher dislocation densities. The back-stresses from the coherent L1(2) precipitate were insufficient to cause improvement in twin nucleation, owing to elevated twinning stress under quasi-static testing. However, under dynamic testing high density of twins were observed.
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spelling pubmed-64788652019-05-03 Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy Gwalani, Bharat Gangireddy, Sindhura Zheng, Yufeng Soni, Vishal Mishra, Rajiv S. Banerjee, Rajarshi Sci Rep Article Recent studies indicate that eutectic high-entropy alloys can simultaneously possess high strength and high ductility, which have potential industrial applications. The present study focuses on Al(0.7)CoCrFeNi, a lamellar dual-phase (fcc + B2) precipitation-strengthenable eutectic high entropy alloy. This alloy exhibits an fcc + B2 (B2 with bcc nano-precipitates) microstructure resulting in a combination of the soft and ductile fcc phase together with hard B2 phase. Low temperature annealing leads to the precipitation of ordered L1(2) intermetallic precipitates within the fcc resulting in enhanced strength. The strengthening contribution due to fine scale L1(2) is modeled using Orowan dislocation bowing and by-pass mechanism. The alloy was tested under quasi-static (strain-rate = 10(−3) s(−1)) tensile loading and dynamic (strain-rate = 10(3) s(−1)) compressive loading. Due to the fine lamellar microstructure with a large number of fcc-bcc interfaces, the alloy show relatively high flow-stresses, ~1400 MPa under quasi-static loading and in excess of 1800 MPa under dynamic loading. Interestingly, the coherent nano-scale L1(2) precipitate caused a significant rise in the yield strength, without affecting the strain rate sensitivity (SRS) significantly. These lamellar structures had higher work hardening due to their capability for easily storing higher dislocation densities. The back-stresses from the coherent L1(2) precipitate were insufficient to cause improvement in twin nucleation, owing to elevated twinning stress under quasi-static testing. However, under dynamic testing high density of twins were observed. Nature Publishing Group UK 2019-04-23 /pmc/articles/PMC6478865/ /pubmed/31015578 http://dx.doi.org/10.1038/s41598-019-42870-y Text en © The Author(s) 2019 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Gwalani, Bharat
Gangireddy, Sindhura
Zheng, Yufeng
Soni, Vishal
Mishra, Rajiv S.
Banerjee, Rajarshi
Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title_full Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title_fullStr Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title_full_unstemmed Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title_short Influence of ordered L1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
title_sort influence of ordered l1(2) precipitation on strain-rate dependent mechanical behavior in a eutectic high entropy alloy
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6478865/
https://www.ncbi.nlm.nih.gov/pubmed/31015578
http://dx.doi.org/10.1038/s41598-019-42870-y
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