CONICET | Buscador de Institutos y Recursos Humanos

Magnesium and its alloys have become a hot research topic for a variety of industries such as electronic, automotive, biomedical, aerospace industries owing to its excellent mechanical and physical properties; particularly, low density, easy recyclability, and high strength-to-weight ratio properties. Nevertheless, their high chemical reactivity makes them highly susceptible to corrosion, limiting their use in such areas. The control of corrosion rate through surface modification techniques has attracted an increasing interest for many researchers. Chromate conversion coatings have reported as one of the most common and efficient system with self‐healing abilities. However, Cr (VI) has health and environmental hazards, so many efforts have been made to look for new strategies. Among the alternatives, plasma electrolytic oxidation (PEO) is one of the most important surface technique based on the creation a natural micro-porous oxide layer by using environmentally friendly electrolytes. However, the oxide layer provides a moderate corrosion protection on metals, because the presence of micro-pores acts as potential sites for penetration of corrosive Cl- ions of electrolytic medium. The modification of the anodizing electrolytes (via the incorporation of different oxysalts) and the post-treatment of the oxide formed by PEO by the deposition of a sol-gel coating can be a good approach to optimize the surface microstructure by reducing the coating porosity. Under this perspective, the aim of this work is to study the effect of using different friendly electrolytes (such as: NaOH, NaH2PO4, Na2SiO4 and Na2CO3) on the microstructure and corrosion properties of the PEO coating, as well as the effect of sol gel coating as a post-treatment after the PEO process. In this study, the conditions of anodization of Mg have been explored together with the preparation and deposition of SiO2 sol obtained by hydrolysis and condensation of TEOS and GPTMS

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