Characterization of processed materials by electrical currents: development of equipment and applications

Detalhes bibliográficos
Autor(a) principal: Sorger, Luís Gonçalo Lourenço
Data de Publicação: 2014
Tipo de documento: Dissertação
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/10362/12180
Resumo: Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica
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spelling Characterization of processed materials by electrical currents: development of equipment and applicationsMaterials characterizationElectrical conductivityEddy currentsFour-point probeDissertação para obtenção do Grau de Mestre em Engenharia MecânicaStructural characterization of welded or processed materials is critical for a correct assessment of their properties. Microstructural analysis by optical microscopy provides information to identify the distinctive zones, their extent and the major transformations induced. For structural analysis, hardness is the simplest property to measure, providing information on the existence of ductile or brittle zones in the material. Furthermore, it can be qualitatively correlated to yield strength. However, these techniques are time consuming and destructive and, therefore, there is need for new, dedicated, preferably non-destructive, characterization methods. The same changes in properties and structure, due to welding and processing, also alter the electrical conductivity of materials. In fact, studies have demonstrated a relation between microstructure and conductivity of friction stir processed Al alloys, relating decreases in this property to the increase in the barriers to electron mobility due to the refined grain of the dynamically recrystallized zone, while the opposite occurs in heat affected zones were grain growth exists. The aim of this thesis was to apply eddy currents electrical conductivity characterization techniques to a wider range of materials, and develop equipment for an alternative electrical current evaluation method, namely, four-point probe potential drop measurements. A prototype for an automated four-point probe electrical conductivity characterization equipment was designed, built and successfully tested. Electrical conductivity characterization techniques, by eddy currents, have been applied to different metallic materials(AISI 1020, AISI 304, AZ31, Ti Grade 5, Ti Grade 2, Lead and Copper) processed by solid-state (Friction Stir Processing (FSP)) and fusion (Metal Active Gas (MAG) and Tungsten Inhert Gas (TIG)) to evaluate the effects on their electrical conductivity profiles and compare them with the hardness profiles and the microstructural features. Results show that the electrical conductivity variations that occur due to welding and processing can be related to the hardness and the microstructure of materials and, depending on the material, this relation can be direct or inverse.Faculdade de Ciências e TecnologiaMiranda, RosaSantos, TelmoRUNSorger, Luís Gonçalo Lourenço2014-06-16T14:59:01Z20142014-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10362/12180enginfo: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:RCAAP2023-07-10T15:31:11ZPortal AgregadorONG
dc.title.none.fl_str_mv Characterization of processed materials by electrical currents: development of equipment and applications
title Characterization of processed materials by electrical currents: development of equipment and applications
spellingShingle Characterization of processed materials by electrical currents: development of equipment and applications
Sorger, Luís Gonçalo Lourenço
Materials characterization
Electrical conductivity
Eddy currents
Four-point probe
title_short Characterization of processed materials by electrical currents: development of equipment and applications
title_full Characterization of processed materials by electrical currents: development of equipment and applications
title_fullStr Characterization of processed materials by electrical currents: development of equipment and applications
title_full_unstemmed Characterization of processed materials by electrical currents: development of equipment and applications
title_sort Characterization of processed materials by electrical currents: development of equipment and applications
author Sorger, Luís Gonçalo Lourenço
author_facet Sorger, Luís Gonçalo Lourenço
author_role author
dc.contributor.none.fl_str_mv Miranda, Rosa
Santos, Telmo
RUN
dc.contributor.author.fl_str_mv Sorger, Luís Gonçalo Lourenço
dc.subject.por.fl_str_mv Materials characterization
Electrical conductivity
Eddy currents
Four-point probe
topic Materials characterization
Electrical conductivity
Eddy currents
Four-point probe
description Dissertação para obtenção do Grau de Mestre em Engenharia Mecânica
publishDate 2014
dc.date.none.fl_str_mv 2014-06-16T14:59:01Z
2014
2014-01-01T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
dc.type.driver.fl_str_mv info:eu-repo/semantics/masterThesis
format masterThesis
status_str publishedVersion
dc.identifier.uri.fl_str_mv http://hdl.handle.net/10362/12180
url http://hdl.handle.net/10362/12180
dc.language.iso.fl_str_mv eng
language eng
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 Faculdade de Ciências e Tecnologia
publisher.none.fl_str_mv Faculdade de Ciências e Tecnologia
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
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instacron_str RCAAP
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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
repository.mail.fl_str_mv
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