Microstructure evolution of AA7050 Al alloy during Equal-Channel Angular Pressing

Microstructure evolution of AA7050 Al alloy during Equal-Channel Angular Pressing

Autor Cardoso, Kátia Regina Autor UNIFESP Google Scholar
Travessa, Dilermando Nagle Autor UNIFESP Google Scholar
Jorge Junior, Alberto Moreira Google Scholar
Botta, Walter José Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
UFSCar Departamento de Engenharia de Materiais
Resumo High strength AA7050 aluminum alloy was processed by ECAP through route A in the T7451 condition. Samples were processed at 423 K, with 1 and 3 passes. The resulting microstructure was evaluated by optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phases were identified by X-ray diffraction (XRD) using monochromatic Cu Kα radiation. Rockwell B hardness and tensile tests were performed for assessment of mechanical properties. The microstructure was refined by the formation of deformation bands, with dislocation cells and elongated subgrains, with an average width of 240 nm, inside these bands. The number of deformation bands increased with the number of passes. A reduction of precipitates size was observed with increase in the number of passes, when compared to initial condition, probably resulting from particle fragmentation during ECAP. After three passes the precipitates tend to a more equiaxed morphology and have sizes smaller than 10 nm. Phases Η' and Η coexist in the microstructure, but Η is the dominant phase, mainly after three passes. The hardness of alloy after the first pass of ECAP is almost equal to the initial condition. After three passes the hardness showed a slight reduction which must be result from recovery process. There was a slight improvement in the yield strength and elongation after one pass, when compared to the initial T7451 condition. The improvement in the ultimate tensile strength was less significant.
Palavra-chave severe plastic deformation
ECAP
aluminum alloy
Idioma Inglês
Financiador Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Número do financiamento FAPESP: 2005/03440-5
Data de publicação 2012-10-01
Publicado em Materials Research. ABM, ABC, ABPol, v. 15, n. 5, p. 732-738, 2012.
ISSN 1516-1439 (Sherpa/Romeo, fator de impacto)
Publicador ABM, ABC, ABPol
Extensão 732-738
Fonte http://dx.doi.org/10.1590/S1516-14392012005000105
Direito de acesso Acesso aberto Open Access
Tipo Artigo
Web of Science WOS:000309191500007
SciELO S1516-14392012000500007 (estatísticas na SciELO)
Endereço permanente http://repositorio.unifesp.br/handle/11600/7322

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