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Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation

One of the difficulties with bobbin friction stir welding (BFSW) has been the visualisation of microstructure, particularly grain boundaries, and this is especially problematic for materials with fine grain structure, such as AA6082-T6 aluminium as here. Welds of this material were examined using op...

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Detalles Bibliográficos
Autores principales: Tamadon, Abbas, Pons, Dirk J., Clucas, Don, Sued, Kamil
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804051/
https://www.ncbi.nlm.nih.gov/pubmed/31581446
http://dx.doi.org/10.3390/ma12193215
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author Tamadon, Abbas
Pons, Dirk J.
Clucas, Don
Sued, Kamil
author_facet Tamadon, Abbas
Pons, Dirk J.
Clucas, Don
Sued, Kamil
author_sort Tamadon, Abbas
collection PubMed
description One of the difficulties with bobbin friction stir welding (BFSW) has been the visualisation of microstructure, particularly grain boundaries, and this is especially problematic for materials with fine grain structure, such as AA6082-T6 aluminium as here. Welds of this material were examined using optical microscopy (OM) and electron backscatter diffraction (EBSD). Results show that the grain structures that form depend on a complex set of factors. The motion of the pin and shoulder features transports material around the weld, which induces shear. The shear deformation around the pin is non-uniform with a thermal and strain gradient across the weld, and hence the dynamic recrystallisation (DRX) processes are also variable, giving a range of observed polycrystalline and grain boundary structures. Partial DRX was observed at both hourglass boundaries, and full DRX at mid-stirring zone. The grain boundary mapping showed the formation of low-angle grain boundaries (LAGBs) at regions of high shear as a consequence of thermomechanical nature of the process.
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spelling pubmed-68040512019-11-18 Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation Tamadon, Abbas Pons, Dirk J. Clucas, Don Sued, Kamil Materials (Basel) Article One of the difficulties with bobbin friction stir welding (BFSW) has been the visualisation of microstructure, particularly grain boundaries, and this is especially problematic for materials with fine grain structure, such as AA6082-T6 aluminium as here. Welds of this material were examined using optical microscopy (OM) and electron backscatter diffraction (EBSD). Results show that the grain structures that form depend on a complex set of factors. The motion of the pin and shoulder features transports material around the weld, which induces shear. The shear deformation around the pin is non-uniform with a thermal and strain gradient across the weld, and hence the dynamic recrystallisation (DRX) processes are also variable, giving a range of observed polycrystalline and grain boundary structures. Partial DRX was observed at both hourglass boundaries, and full DRX at mid-stirring zone. The grain boundary mapping showed the formation of low-angle grain boundaries (LAGBs) at regions of high shear as a consequence of thermomechanical nature of the process. MDPI 2019-10-01 /pmc/articles/PMC6804051/ /pubmed/31581446 http://dx.doi.org/10.3390/ma12193215 Text en © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Tamadon, Abbas
Pons, Dirk J.
Clucas, Don
Sued, Kamil
Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title_full Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title_fullStr Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title_full_unstemmed Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title_short Texture Evolution in AA6082-T6 BFSW Welds: Optical Microscopy and EBSD Characterisation
title_sort texture evolution in aa6082-t6 bfsw welds: optical microscopy and ebsd characterisation
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804051/
https://www.ncbi.nlm.nih.gov/pubmed/31581446
http://dx.doi.org/10.3390/ma12193215
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