Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms
Autor(a) principal: | |
---|---|
Data de Publicação: | 2012 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.9/1662 |
Resumo: | The present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles. |
id |
RCAP_44b8397126398f112d5c1a7e6aaa8730 |
---|---|
oai_identifier_str |
oai:repositorio.lneg.pt:10400.9/1662 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanismsNanocompositesNanodiamondHall–Petch relationMechanical synthesisCarbide formationThe present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles.ElsevierRepositório do LNEGNunes, D.Vilarigues, M.Correia, J.B.Carvalho, Patricia Almeida2013-02-26T15:32:15Z2012-01-01T00:00:00Z2012-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.9/1662engNunes, D.; Vilarigues, M.; Correia, J.B.; Carvalho, P.A. Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms. In: Acta Materialia, 2012, vol. 60, nº2, p.737-7471359-6454info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2022-09-06T12:26:14Zoai:repositorio.lneg.pt:10400.9/1662Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:34:26.500928Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
title |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
spellingShingle |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms Nunes, D. Nanocomposites Nanodiamond Hall–Petch relation Mechanical synthesis Carbide formation |
title_short |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
title_full |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
title_fullStr |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
title_full_unstemmed |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
title_sort |
Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms |
author |
Nunes, D. |
author_facet |
Nunes, D. Vilarigues, M. Correia, J.B. Carvalho, Patricia Almeida |
author_role |
author |
author2 |
Vilarigues, M. Correia, J.B. Carvalho, Patricia Almeida |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Repositório do LNEG |
dc.contributor.author.fl_str_mv |
Nunes, D. Vilarigues, M. Correia, J.B. Carvalho, Patricia Almeida |
dc.subject.por.fl_str_mv |
Nanocomposites Nanodiamond Hall–Petch relation Mechanical synthesis Carbide formation |
topic |
Nanocomposites Nanodiamond Hall–Petch relation Mechanical synthesis Carbide formation |
description |
The present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-01-01T00:00:00Z 2012-01-01T00:00:00Z 2013-02-26T15:32:15Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.9/1662 |
url |
http://hdl.handle.net/10400.9/1662 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Nunes, D.; Vilarigues, M.; Correia, J.B.; Carvalho, P.A. Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms. In: Acta Materialia, 2012, vol. 60, nº2, p.737-747 1359-6454 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Elsevier |
publisher.none.fl_str_mv |
Elsevier |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799130208325861376 |