LDH conversion films for active protection of AZ31 Mg alloy

Autor: B. Pillado, B. Mingo, R. del Olmo, E. Matykina, A.M. Kooijman, Y. Gonzalez−Garcia, R. Arrabal, M. Mohedano
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Pillado, B, Mingo, B, del Olmo, R, Endzhe, M, Kooijman, A M, Gonzalez-Garcia, Y, Arrabal, R & Mohedano, M 2022, ' LDH conversion films for active protection of AZ31 Mg alloy ', Journal of Magnesium and Alloys . https://doi.org/10.1016/j.jma.2022.09.014
Journal of Magnesium and Alloys, 11(1)
ISSN: 2213-9567
DOI: 10.1016/j.jma.2022.09.014
Popis: Zinc aluminium (Zn-Al) and lithium aluminium (Li-Al) – layered double hydroxides (LDH) coatings with incorporated inhibitors (Li−, Mo− and W−based) were successfully synthesized on AZ31 Mg alloy. Zn−Al LDH W and Li−Al LDH Li showed the highest corrosion resistance and were selected for further evaluation. SEM cross−section examination revealed a bi−layer structure composed of an outer part with loose flakes and a denser inner layer. XRD, FTIR, and XPS analysis confirmed the incorporation of the inhibitors. Post−treatments with corrosion inhibitors containing solutions resulted in the selective dissolution of the most external layer of the LDH coating, reducing the surface roughness, hydrophilicity and paint adhesion of the layers. Active corrosion properties were confirmed by SVET evaluation for the Zn−Al LDH W coating. The proposed active corrosion mechanism involves the ion−exchange of aggressive Cl− ions, deposition of hydroxides and competitive adsorption of W−rich corrosion inhibitors.
Databáze: OpenAIRE