Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam
Autor(a) principal: | |
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Data de Publicação: | 2007 |
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/10400.9/1083 |
Resumo: | In equilibrium binary W-C system, mono-carbide WC is acknowledged as the stable phase under presence of excess free carbon up to temperature 2700 C whereas sub-carbideW2C would form between 1250 C and 2700 C under the carbon-deficiency condition. In unique setup of solar furnace at PROMES-CNRS in Odeillo (France), temperature of specimen is raised from the ambient temperature to target temperature up to 2000 C within fractions of a second. In the recent experimental attempts of W2C phase synthesis using this unique experimental facility starting from compacted pellet consisted of graphite and tungsten powders at ratios smaller than 0.50, we detected growth of nano-meter size WC whisker at the top surface directly exposed to the concentrated solar beam. The presence of WC was confirmed also by X-ray diffraction (XRD) of the top surface but, when the specimen as a whole was subjected to powder XRD analysis, WC became indiscernible being masked by principal W2C phase. Mechanism of formation of the detected WC nano-whisker over sub-stoichiometric C/W pellet during ultra-fast heating by concentrated solar beam is discussed. |
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Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beamTungsten mono-carbide nano-whiskerScanning electron microscopySolar furnaceUltra-fast heatingIn equilibrium binary W-C system, mono-carbide WC is acknowledged as the stable phase under presence of excess free carbon up to temperature 2700 C whereas sub-carbideW2C would form between 1250 C and 2700 C under the carbon-deficiency condition. In unique setup of solar furnace at PROMES-CNRS in Odeillo (France), temperature of specimen is raised from the ambient temperature to target temperature up to 2000 C within fractions of a second. In the recent experimental attempts of W2C phase synthesis using this unique experimental facility starting from compacted pellet consisted of graphite and tungsten powders at ratios smaller than 0.50, we detected growth of nano-meter size WC whisker at the top surface directly exposed to the concentrated solar beam. The presence of WC was confirmed also by X-ray diffraction (XRD) of the top surface but, when the specimen as a whole was subjected to powder XRD analysis, WC became indiscernible being masked by principal W2C phase. Mechanism of formation of the detected WC nano-whisker over sub-stoichiometric C/W pellet during ultra-fast heating by concentrated solar beam is discussed.Repositório do LNEGDias, SusanaOliveira, Fernando Almeida CostaGranier, BernardBadie, Jean MarieFernandes, Jorge CruzRosa, Luís GuerraShohoji, Nobumitsu2010-12-02T15:58:48Z20072007-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.9/1083engDias, S.; Oliveira, F. A. C.; Granier, B.; Badie, J. M.; Fernandes, J. C.; Rosa, L. G.; Shohoji, N. Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam. In: Materials Transactions, 2007, vol. 48, nº. 5, p. 919- 923info: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:RCAAP2022-12-04T04:44:53Zoai:repositorio.lneg.pt:10400.9/1083Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T15:33:54.281514Repositório 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 |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
title |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
spellingShingle |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam Dias, Susana Tungsten mono-carbide nano-whisker Scanning electron microscopy Solar furnace Ultra-fast heating |
title_short |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
title_full |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
title_fullStr |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
title_full_unstemmed |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
title_sort |
Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam |
author |
Dias, Susana |
author_facet |
Dias, Susana Oliveira, Fernando Almeida Costa Granier, Bernard Badie, Jean Marie Fernandes, Jorge Cruz Rosa, Luís Guerra Shohoji, Nobumitsu |
author_role |
author |
author2 |
Oliveira, Fernando Almeida Costa Granier, Bernard Badie, Jean Marie Fernandes, Jorge Cruz Rosa, Luís Guerra Shohoji, Nobumitsu |
author2_role |
author author author author author author |
dc.contributor.none.fl_str_mv |
Repositório do LNEG |
dc.contributor.author.fl_str_mv |
Dias, Susana Oliveira, Fernando Almeida Costa Granier, Bernard Badie, Jean Marie Fernandes, Jorge Cruz Rosa, Luís Guerra Shohoji, Nobumitsu |
dc.subject.por.fl_str_mv |
Tungsten mono-carbide nano-whisker Scanning electron microscopy Solar furnace Ultra-fast heating |
topic |
Tungsten mono-carbide nano-whisker Scanning electron microscopy Solar furnace Ultra-fast heating |
description |
In equilibrium binary W-C system, mono-carbide WC is acknowledged as the stable phase under presence of excess free carbon up to temperature 2700 C whereas sub-carbideW2C would form between 1250 C and 2700 C under the carbon-deficiency condition. In unique setup of solar furnace at PROMES-CNRS in Odeillo (France), temperature of specimen is raised from the ambient temperature to target temperature up to 2000 C within fractions of a second. In the recent experimental attempts of W2C phase synthesis using this unique experimental facility starting from compacted pellet consisted of graphite and tungsten powders at ratios smaller than 0.50, we detected growth of nano-meter size WC whisker at the top surface directly exposed to the concentrated solar beam. The presence of WC was confirmed also by X-ray diffraction (XRD) of the top surface but, when the specimen as a whole was subjected to powder XRD analysis, WC became indiscernible being masked by principal W2C phase. Mechanism of formation of the detected WC nano-whisker over sub-stoichiometric C/W pellet during ultra-fast heating by concentrated solar beam is discussed. |
publishDate |
2007 |
dc.date.none.fl_str_mv |
2007 2007-01-01T00:00:00Z 2010-12-02T15:58:48Z |
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/10400.9/1083 |
url |
http://hdl.handle.net/10400.9/1083 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
Dias, S.; Oliveira, F. A. C.; Granier, B.; Badie, J. M.; Fernandes, J. C.; Rosa, L. G.; Shohoji, N. Nano-meter size WC whiskers grown over a compacted pellet of praphite: tungsten powder mixture heated with an ultra-fast heating rate by a concentrated solar beam. In: Materials Transactions, 2007, vol. 48, nº. 5, p. 919- 923 |
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.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 |
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