Improving corrosion protection of Mg alloys (AZ31B) using graphene-based hybrid coatings

[EN] In the present work, a study was carried out to compare the morphology and electrochemical properties of pure and graphene-modified hybrid silica sol–gel coatings deposited on anodized AZ31B magnesium alloys. The precursor solution was prepared using tetraethoxysilane (TEOS) and 3-glycidoxyprop...

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Detalles Bibliográficos
Autores: Afsharimani, Nasima, Talimian, Ali, Merino, Emilia, Durán, Alicia, Castro Martín, Yolanda, Galusek, Dušan
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/267325
Acceso en línea:http://hdl.handle.net/10261/267325
Access Level:acceso abierto
Palabra clave:Barrier properties
Corrosion protection
Graphene nanosheets
Magnesium alloy
Sol–gelcoatings
Descripción
Sumario:[EN] In the present work, a study was carried out to compare the morphology and electrochemical properties of pure and graphene-modified hybrid silica sol–gel coatings deposited on anodized AZ31B magnesium alloys. The precursor solution was prepared using tetraethoxysilane (TEOS) and 3-glycidoxypropyl-trimethoxysilane (GPTMS), with the addition of chemically modified graphene nanosheets (GN-chem). Homogeneous and adherent coatings were obtained using GPTMS-TEOS (GT) and GPTMS-TEOS-GN-chem (GT/GN-chem) solutions with uniform thickness around 4 µm. Raman, SEM images and EDS analyses confirmed the presence of graphene nanosheets in the coatings. Potentiodynamic polarization results using 0.05 M NaCl electrolyte solution showed that graphene containing silica coatings significantly improve the corrosion resistance of AZ31B alloys. In addition, a significant passive region was observed for GT/GN-chem coatings.