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Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals

Design and processing of advanced lightweight structural alloys based on magnesium and titanium rely critically on a control over twinning that remains elusive to date and is dependent on an explicit understanding on the twinning nucleation mechanism in hexagonal close-packed (HCP) crystals. Here, b...

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Autores principales: He, Yang, Li, Bin, Wang, Chongmin, Mao, Scott X.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235251/
https://www.ncbi.nlm.nih.gov/pubmed/32424342
http://dx.doi.org/10.1038/s41467-020-16351-0
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author He, Yang
Li, Bin
Wang, Chongmin
Mao, Scott X.
author_facet He, Yang
Li, Bin
Wang, Chongmin
Mao, Scott X.
author_sort He, Yang
collection PubMed
description Design and processing of advanced lightweight structural alloys based on magnesium and titanium rely critically on a control over twinning that remains elusive to date and is dependent on an explicit understanding on the twinning nucleation mechanism in hexagonal close-packed (HCP) crystals. Here, by using in-situ high resolution transmission electron microscopy, we directly show a dual-step twinning nucleation mechanism in HCP rhenium nanocrystals. We find that nucleation of the predominant {1 0 −1 2} twinning is initiated by disconnections on the Prismatic│Basal interfaces which establish the lattice correspondence of the twin with a minor deviation from the ideal orientation. Subsequently, the minor deviation is corrected by the formation of coherent twin boundaries through rearrangement of the disconnections on the Prismatic│Basal interface; thereafter, the coherent twin boundaries propagate by twinning dislocations. The findings provide high-resolution direct evidence of the twinning nucleation mechanism in HCP crystals.
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spelling pubmed-72352512020-05-20 Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals He, Yang Li, Bin Wang, Chongmin Mao, Scott X. Nat Commun Article Design and processing of advanced lightweight structural alloys based on magnesium and titanium rely critically on a control over twinning that remains elusive to date and is dependent on an explicit understanding on the twinning nucleation mechanism in hexagonal close-packed (HCP) crystals. Here, by using in-situ high resolution transmission electron microscopy, we directly show a dual-step twinning nucleation mechanism in HCP rhenium nanocrystals. We find that nucleation of the predominant {1 0 −1 2} twinning is initiated by disconnections on the Prismatic│Basal interfaces which establish the lattice correspondence of the twin with a minor deviation from the ideal orientation. Subsequently, the minor deviation is corrected by the formation of coherent twin boundaries through rearrangement of the disconnections on the Prismatic│Basal interface; thereafter, the coherent twin boundaries propagate by twinning dislocations. The findings provide high-resolution direct evidence of the twinning nucleation mechanism in HCP crystals. Nature Publishing Group UK 2020-05-18 /pmc/articles/PMC7235251/ /pubmed/32424342 http://dx.doi.org/10.1038/s41467-020-16351-0 Text en © The Author(s) 2020 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
He, Yang
Li, Bin
Wang, Chongmin
Mao, Scott X.
Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title_full Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title_fullStr Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title_full_unstemmed Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title_short Direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
title_sort direct observation of dual-step twinning nucleation in hexagonal close-packed crystals
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7235251/
https://www.ncbi.nlm.nih.gov/pubmed/32424342
http://dx.doi.org/10.1038/s41467-020-16351-0
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