abstract
Layered double hydroxides (LDH) have emerged as an alternative to chromates for corrosion protection by exploiting anion-exchange phenomena: the LDH releases corrosion inhibitor anions and captures the corrosive agent anions, extending the metal surface lifetime. In this work, the main aim was to promote continuation of corrosion protection after the end of the process of anion-exchange. For this purpose, cerium cations, which possess corrosion protection capability, were incorporated in the LDH structure via partial substitution of aluminium cations. The changes occurring to the LDH in solution after exposure for an extended period of 30 days to UV radiation, were evaluated. The study was performed using Mg3Al1-xCex LDH intercalated with nitrate, where x was 7.5 mol%, Ce3+ release from the hydroxide layers being promoted by UV-radiation-induced LDH degradation. The release of Ce3+ from the hydroxide layers was quantified by UV-visible spectroscopy. The continued corrosion protection of aluminium alloy 2024 immersed in a solution with and without the presence of degraded LDH was examined by electrochemical impedance spectroscopy and surface analysis.
keywords
COATINGS; DEGRADATION; INHIBITION; RESISTANCE
subject category
Chemistry; Materials Science; Physics
authors
Vieira, DEL; Salak, AN; Ferreira, MGS; Vieira, JM; Brett, CMA
our authors
Andrei Salak
Principal Researcher
Daniel Eduardo Loureiro Vieira
PhD Student
Joaquim Manuel Vieira
Retired Professor
Mário Guerreiro Silva Ferreira
Retired ProfessorGroups
G2 - Photonic, Electronic and Magnetic Materials
G3 - Electrochemical Materials, Interfaces and Coatings
acknowledgements
Daniel E. L. Vieira acknowledges the support of this work through the AdvaMtech PhD programme scholarship PD/BD/143033/2018. This work was carried out within the framework CICECO-Aveiro Institute of Materials, projects UIDB/50011/2020 & UIDP/50011/2020, and CEMMPRE, Coimbra, project UIDB/00285/2020 by national funds through FCT -Fundacao para a Ci <^>encia e a Tecnologia, Portugal.