Effect of naturally formed oxide films and other variables in the early stages of Mg-alloy corrosion in NaCl solution

The influence of initial surface conditions on the subsequent corrosion behaviour of AZ31 and AZ61 magnesium alloys in 0.6 M NaCl solution has been studied using electrochemical impedance spectroscopy. For obtaining the different surface conditions, some of the specimens were immersion tested with t...

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Detalhes bibliográficos
Autores: Feliú Jr., S., Maffiotte, C., Samaniego, Alejandro, Galván Sierra, Juan Carlos, Barranco, Violeta
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2011
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/96374
Acesso em linha:http://hdl.handle.net/10261/96374
Access Level:Acceso aberto
Palavra-chave:Magnesium alloys
Aluminium
Chloride
Electrochemical impedance spectroscopy
X-ray photoelectron spectroscopy
Descrição
Resumo:The influence of initial surface conditions on the subsequent corrosion behaviour of AZ31 and AZ61 magnesium alloys in 0.6 M NaCl solution has been studied using electrochemical impedance spectroscopy. For obtaining the different surface conditions, some of the specimens were immersion tested with the surface in the as-received condition, while others were tested immediately after mechanical polishing, and part of the polished specimens after six months of exposure to the laboratory atmosphere. Considering the evolution of the high-frequency capacitive arc of the Nyquist diagram, whose diameter is related to the corrosion process, a clear effect of the initial surface conditions is observed only in the early stages of testing. This effect is especially significant for the freshly polished specimens