Novel smart and self-healing cerium phosphate-based corrosion inhibitor for AZ31 magnesium alloy. (1st July 2020)

• Record Type: Journal Article
• Authors: Calado, Lénia M.; Taryba, Maryna G.; Morozov, Yegor; Carmezim, Maria J.; Montemor, M. Fátima
• Is Part Of: Corrosion science. Volume 170(2020)
• Publication Date: 2020-07-01
• Subjects: A. Magnesium -- A. Alloy -- A. Organic coatings -- A. Rare earth elements -- B. EIS; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.108648
• Languages: English
• ISSNs: 0010-938X

Abstract

Graphical abstract: Highlights: Modification of hybrid epoxy-silane coating with Ce(DEHP)3 corrosion inhibitor. Improved corrosion protection of AZ31 with Ce(DEHP)3 . Cyclic corrosion inhibition effect of Ce(DEHP)3 . Self-healing in coating defects in the presence of the inhibitor. pH-activated corrosion inhibitor. Abstract: Tri(bis(2-ethylhexyl)phosphate) (Ce(DEHP)3 ) was used as novel corrosion inhibitor for protection of AZ31 coated with an epoxy-silane hybrid coating. Electrochemical Impedance Spectroscopy (EIS) in 0.05 M NaCl showed that Ce(DEHP)3 -modified coating offered superior corrosion protection compared to a reference coating. Localized electrochemical techniques (Localized Electrochemical Impedance Spectroscopy – LEIS, Scanning Vibrating Electrode Technique – SVET, and Scanning Ion-Selective Electrode Technique – SIET) were employed to assess the corrosion healing effect of Ce(DEHP)3 in defect-containing coatings. Results showed that Ce(DEHP)3 introduces cyclic pH-dependent corrosion inhibition, involving the combined action of cerium and organophosphate ions through formation of protective Ce- and P-containing species.