Interface structures in Al-Nb2O5 nanocomposites processed by high-pressure torsion at room temperature
Interface structures in Al-Nb2O5 nanocomposites processed by high-pressure torsion at room temperature
Extremely thin Nb2O5 nanowires and Al powder were successfully consolidated at room temperature by using high-pressure torsion (HPT), producing a novel metal matrix nanocomposite with exceptional mechanical properties. It is shown that minor additions of Nb2O5 increase sharply the hardness of commercially pure Al. For instance, hardness of over 180 Hv was developed at the edge of samples with 10% nanowires and processed through 10 turns of HPT. This is markedly higher than any other value reported for pure aluminum matrix composites having this level of reinforcement phase. A detailed characterization of the interface structure using high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) revealed a pronounced grain refinement of the Al matrix at the nanoscale and the occurrence of the aluminothermic reduction of the Nb2O5. The latter led to: (i) the formation of Al2O3 nanolayer at the Al/Nb2O5 interface and (ii) the nanosegregation of metallic Nb (with few atomic layers) along grain boundaries and dislocations. The pronounced increase in hardness is attributed to the formation of this interface nanostructure.
HPT, hardness, high-pressure torsion, nanocomposite, niobium oxide, segregation
Silva, Clenio
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Montoro, Luciano A
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Martins, Debora A A
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Machado, Priscila A
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Pereira, Pedro Henrique R.
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Golzalez, Berenice M
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Langdon, Terence G
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Figueiredo, Roberto B
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Isaac Neta, Augusta C.
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April 2020
Silva, Clenio
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Montoro, Luciano A
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Martins, Debora A A
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Machado, Priscila A
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Pereira, Pedro Henrique R.
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Golzalez, Berenice M
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Langdon, Terence G
86e69b4f-e16d-4830-bf8a-5a9c11f0de86
Figueiredo, Roberto B
cdc0ae83-425e-43ac-be02-3fb382c35981
Isaac Neta, Augusta C.
8bbd9d2d-a43b-442f-8d29-ae1a319ca616
Silva, Clenio, Montoro, Luciano A, Martins, Debora A A, Machado, Priscila A, Pereira, Pedro Henrique R., Golzalez, Berenice M, Langdon, Terence G, Figueiredo, Roberto B and Isaac Neta, Augusta C.
(2020)
Interface structures in Al-Nb2O5 nanocomposites processed by high-pressure torsion at room temperature.
Materials Characterization, 162, [110222].
(doi:10.1016/j.matchar.2020.110222).
Abstract
Extremely thin Nb2O5 nanowires and Al powder were successfully consolidated at room temperature by using high-pressure torsion (HPT), producing a novel metal matrix nanocomposite with exceptional mechanical properties. It is shown that minor additions of Nb2O5 increase sharply the hardness of commercially pure Al. For instance, hardness of over 180 Hv was developed at the edge of samples with 10% nanowires and processed through 10 turns of HPT. This is markedly higher than any other value reported for pure aluminum matrix composites having this level of reinforcement phase. A detailed characterization of the interface structure using high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) revealed a pronounced grain refinement of the Al matrix at the nanoscale and the occurrence of the aluminothermic reduction of the Nb2O5. The latter led to: (i) the formation of Al2O3 nanolayer at the Al/Nb2O5 interface and (ii) the nanosegregation of metallic Nb (with few atomic layers) along grain boundaries and dislocations. The pronounced increase in hardness is attributed to the formation of this interface nanostructure.
Text
Isaac-MC-2020
- Accepted Manuscript
More information
Accepted/In Press date: 20 February 2020
e-pub ahead of print date: 20 February 2020
Published date: April 2020
Additional Information:
Funding Information:
The authors acknowledge LME/LNNano/CNPEM for providing the equipment and technical support during the experiments involving electron microscopy. AI acknowledges the financial support from FAPEMIG (grant # APQ-02786-14 ); and RBF , CNPq (grant # 400407/2016-7 ) and FAPEMIG (grant # APQ-00580-15 ). TGL was supported in part by the European Research Council under ERC Grant Agreement No. 267464-SPDMETALS .
Publisher Copyright:
© 2020 Elsevier Inc.
Keywords:
HPT, hardness, high-pressure torsion, nanocomposite, niobium oxide, segregation
Identifiers
Local EPrints ID: 438632
URI: http://eprints.soton.ac.uk/id/eprint/438632
ISSN: 1044-5803
PURE UUID: fd377a99-21d0-4b40-bd43-06d1b5a11707
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Date deposited: 19 Mar 2020 17:30
Last modified: 17 Mar 2024 05:24
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Contributors
Author:
Clenio Silva
Author:
Luciano A Montoro
Author:
Debora A A Martins
Author:
Priscila A Machado
Author:
Pedro Henrique R. Pereira
Author:
Berenice M Golzalez
Author:
Roberto B Figueiredo
Author:
Augusta C. Isaac Neta
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