Flash-PEO coatings loaded with corrosion inhibitors on AA2024

Flash plasma electrolytic oxidation (flash-PEO) with in situ incorporation of inhibitors is explored as a strategy for corrosion protection of 2024 aluminium (Al) alloys. Thin (~5 μm) and energy-efficient coatings were successfully developed on the Al substrate in 100 s treatment time using differen...

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Detalles Bibliográficos
Autores: Olmo Martínez, Rubén del, Mohedano Sánchez, Marta, Visser, Peter, Matykina, Endzhe, Arrabal Durán, Raúl
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/6872
Acceso en línea:https://hdl.handle.net/20.500.14352/6872
Access Level:acceso abierto
Palabra clave:66.0
620
Plasma electrolytic oxidation
Corrosion
Inhibitor
Paint adhesion
Aluminium
Salt spray
Ingeniería química
Materiales
3303 Ingeniería y Tecnología Químicas
3312 Tecnología de Materiales
Descripción
Sumario:Flash plasma electrolytic oxidation (flash-PEO) with in situ incorporation of inhibitors is explored as a strategy for corrosion protection of 2024 aluminium (Al) alloys. Thin (~5 μm) and energy-efficient coatings were successfully developed on the Al substrate in 100 s treatment time using different electrolytes based on molybdate, stannate, tungstate, vanadate lanthanum or cerium salts additives with and without complexing agent (EDTA). Screening of the optimum combination in search of minimum thickness and best corrosion protective performance was performed using electrochemical impedance spectroscopy (EIS). Coatings based on EDTA-Ce and WO42 were selected and investigated further in comparison with the inhibitor-free phosphate coating in terms of morphology, composition, corrosion behaviour and paint adhesion. EDTA-Ce coating showed excellent paint adhesion and the highest impedance modulus at short immersion times in 3.5 wt% NaCl aqueous solution. Neutral salt spray testing of this coating as a full system comprising an epoxy primer showed no signs of corrosion after 1000 h of exposure.