Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening

Several recent papers report spectacular, and unexpected, order of magnitude improvement in creep life of alloys upon adding small amounts of elements like zinc. This microalloying effect raises fundamental questions regarding creep deformation mechanisms. Here, using atomic-scale characterization a...

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Main Authors: Choudhuri, Deep, Srinivasan, Srivilliputhur G., Gibson, Mark A., Zheng, Yufeng, Jaeger, David L., Fraser, Hamish L., Banerjee, Rajarshi
Other Authors: School of Materials Science & Engineering
Format: Article
Language:English
Published: 2018
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Online Access:https://hdl.handle.net/10356/87415
http://hdl.handle.net/10220/44425
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-874152023-07-14T15:51:40Z Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening Choudhuri, Deep Srinivasan, Srivilliputhur G. Gibson, Mark A. Zheng, Yufeng Jaeger, David L. Fraser, Hamish L. Banerjee, Rajarshi School of Materials Science & Engineering Magnesium Alloy Several recent papers report spectacular, and unexpected, order of magnitude improvement in creep life of alloys upon adding small amounts of elements like zinc. This microalloying effect raises fundamental questions regarding creep deformation mechanisms. Here, using atomic-scale characterization and first principles calculations, we attribute the 600% increase in creep life in a prototypical Mg–rare earth (RE)–Zn alloy to multiple mechanisms caused by RE–Zn bonding—stabilization of a large volume fraction of strengthening precipitates on slip planes, increase in vacancy diffusion barrier, reduction in activated cross-slip, and enhancement of covalent character and bond strength around Zn solutes along the c-axis of Mg. We report that increased vacancy diffusion barrier, which correlates with the observed 25% increase in interplanar bond stiffness, primarily enhances the high-temperature creep life. Thus, we demonstrate that an approach of local, randomized tailoring of bond stiffness via microalloying enhances creep performance of alloys. Published version 2018-02-09T03:17:50Z 2019-12-06T16:41:22Z 2018-02-09T03:17:50Z 2019-12-06T16:41:22Z 2017 Journal Article Choudhuri, D., Srinivasan, S. G., Gibson, M. A., Zheng, Y., Jaeger, D. L., Fraser, H. L., et al. (2017). Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening. Nature Communications, 8(1), 2000-. https://hdl.handle.net/10356/87415 http://hdl.handle.net/10220/44425 10.1038/s41467-017-02112-z en Nature Communications © 2017 The Author(s) (Nature Publishing Group). 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/. 9 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Magnesium
Alloy
spellingShingle Magnesium
Alloy
Choudhuri, Deep
Srinivasan, Srivilliputhur G.
Gibson, Mark A.
Zheng, Yufeng
Jaeger, David L.
Fraser, Hamish L.
Banerjee, Rajarshi
Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
description Several recent papers report spectacular, and unexpected, order of magnitude improvement in creep life of alloys upon adding small amounts of elements like zinc. This microalloying effect raises fundamental questions regarding creep deformation mechanisms. Here, using atomic-scale characterization and first principles calculations, we attribute the 600% increase in creep life in a prototypical Mg–rare earth (RE)–Zn alloy to multiple mechanisms caused by RE–Zn bonding—stabilization of a large volume fraction of strengthening precipitates on slip planes, increase in vacancy diffusion barrier, reduction in activated cross-slip, and enhancement of covalent character and bond strength around Zn solutes along the c-axis of Mg. We report that increased vacancy diffusion barrier, which correlates with the observed 25% increase in interplanar bond stiffness, primarily enhances the high-temperature creep life. Thus, we demonstrate that an approach of local, randomized tailoring of bond stiffness via microalloying enhances creep performance of alloys.
author2 School of Materials Science & Engineering
author_facet School of Materials Science & Engineering
Choudhuri, Deep
Srinivasan, Srivilliputhur G.
Gibson, Mark A.
Zheng, Yufeng
Jaeger, David L.
Fraser, Hamish L.
Banerjee, Rajarshi
format Article
author Choudhuri, Deep
Srinivasan, Srivilliputhur G.
Gibson, Mark A.
Zheng, Yufeng
Jaeger, David L.
Fraser, Hamish L.
Banerjee, Rajarshi
author_sort Choudhuri, Deep
title Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
title_short Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
title_full Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
title_fullStr Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
title_full_unstemmed Exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
title_sort exceptional increase in the creep life of magnesium rare-earth alloys due to localized bond stiffening
publishDate 2018
url https://hdl.handle.net/10356/87415
http://hdl.handle.net/10220/44425
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