AlSiC thermal spray coatings for corrosion protection of Mg–Al alloys in humid and saline environments

The corrosion behaviour of thermal spray Al/SiC coatings deposited on AZ31, AZ80 and AZ91D Mg–Al–Zn alloys was evaluated in neutral salt fog (ASTM B 117) and high relative humidity (98% RH, 50 °C) environments. The findings revealed porous as-sprayed coatings with paths providing access of the corro...

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Detalles Bibliográficos
Autores: Arrabal Durán, Raúl, Pardo Gutiérrez Del Cid, Ángel, Merino Casals, María Concepción, Mohedano Sánchez, Marta, Casajús, P., Merino, S.
Tipo de recurso: artículo
Fecha de publicación:2010
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/107712
Acceso en línea:https://hdl.handle.net/20.500.14352/107712
Access Level:acceso abierto
Palabra clave:66
Magnesium
Metal matrix composite
Aluminium
Coatings
Materiales
3312 Tecnología de Materiales
3303 Ingeniería y Tecnología Químicas
Descripción
Sumario:The corrosion behaviour of thermal spray Al/SiC coatings deposited on AZ31, AZ80 and AZ91D Mg–Al–Zn alloys was evaluated in neutral salt fog (ASTM B 117) and high relative humidity (98% RH, 50 °C) environments. The findings revealed porous as-sprayed coatings with paths providing access of the corrosive media to the magnesium substrates. This resulted in galvanic corrosion at the substrate/coating interfaces and formation of magnesium corrosion products, which eventually led to coating spalling in the case of salt fog tests after protracted times of exposure. The application of a cold-pressing post-treatment improved the corrosion performance of the coatings. Thus, in high humidity atmosphere, corrosion signs were only visible at the Al/SiC interfaces in the outermost surface of the coatings and, in salt fog environment, the galvanic corrosion of the substrates was delayed.