Active protective PEO coatings on AA2024 role of voltage on insitu LDH growth

Four voltage-controlled plasma electrolytic oxidation (PEO) coatings were developed on AA2024 aluminum alloy at 350 V, 400 V, 450 V and 500 V. Zn–Al LDH layer was in situ grown and loaded with corrosion inhibitor (vanadate) on the coatings to provide active protection to the PEO layers. The structur...

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Detalhes bibliográficos
Autores: Mohedano Sánchez, Marta, Serdechnova, M., Starykevich, M., Karpushenkov, S., Bouali, A.C., Ferreira, M.G.S., Zheludkevich, M.L.
Formato: artículo
Fecha de publicación:2017
País:España
Recursos:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/107270
Acesso em linha:https://hdl.handle.net/20.500.14352/107270
Access Level:acceso abierto
Palavra-chave:66
PEO
Active protection
Corrosion
LDH
Materiales
3312 Tecnología de Materiales
3303 Ingeniería y Tecnología Químicas
Descrição
Resumo:Four voltage-controlled plasma electrolytic oxidation (PEO) coatings were developed on AA2024 aluminum alloy at 350 V, 400 V, 450 V and 500 V. Zn–Al LDH layer was in situ grown and loaded with corrosion inhibitor (vanadate) on the coatings to provide active protection to the PEO layers. The structure, morphology and composition of PEO coatings without and with LDH-NO3 and LDH-VOx were investigated using SEM, EDS, XRD and GDOES. Coatings formed at higher voltages (thicker and more stable) reveal a decrease of LDH flakes on the surface. The corrosion behavior and the effectiveness of LDH formation and inhibitor intercalation were also studied. Electrochemical impedance spectroscopy and scanning vibrating electrode techniques have shown a remarkable increase in the corrosion resistance of the LDH-inhibitor treated sample in comparison with PEO coated AA2024 specimen.