The study of protective film formation on Mg alloys by exposure to sodium selenite solutions was conducted. Anodic polarization studies, electrochemical impedance spectroscopy studies, morphological analysis, and Energy-dispersive X-ray spectroscopy were performed on AZ31 Mg alloy after coating treatment in different concentrations of sodium selenite. The corrosion resistance was improved by around 5 times compared with control. Improved resistance to localized corrosion was observed in the coatings treated by 5 mM or 10 mM sodium selenite. The protection mechanism was ascribed to the transformation of selenite to insoluble selenium, the formation of insoluble MgSeO3 hydrate, and polymerization of amorphous selenium.
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This research was funded by The Army Research Laboratory grant number W911NF-14-2- 0004.
The following are available online at https://www.mdpi.com/1996-194 4/14/2/286/s1, Figure S1: Bode plot for control, Figure S2: Bode Plot for 1 mM Selenite, Figure S3: Bode Plot for 5 mM Selenite, Figure S4: Bode Plot for 10 mM Selenite.
The above materials are also available as the additional file listed at the end of this record.
Feng, Zhiyuan; Xu, Charles C.; Zhang, Dadi; and Buchheit, Rudolph, "Corrosion Protective Film Formation on Mg Alloys AZ 31 by Exposure to Dilute Selenite Solutions" (2021). Chemical and Materials Engineering Faculty Publications. 76.