Anodic oxidation of Mg–Sn alloys in alkaline solutions

Anodic oxidation behaviour of Mg–Sn alloys was studied to elucidate the effect of Sn content in Mg alloy on the formation of anodic films in alkaline solutions. The anodic films become less resistive by the presence of Sn in Mg in 0.1 M NaOH, while the anodic films formed in 0.1 M NaOH + 0.1 M KF becomes more resistive with increasing Sn content in Mg. Generation of microarcs during the anodizing was observed only in a fluoride-containing solution for Mg–6Sn and Mg–8Sn. Corrosion resistance of the anodized Mg–Sn alloys in the fluoride-containing solution increased with increasing Sn content in Mg.

► Anodic oxidation behaviour of Mg–xSn alloys in alkaline solutions is reported.
► Anodic films formed on Mg–xSn alloys become less resistive by the presence of Sn in alkaline solution.
► Anodic films formed on Mg–xSn alloys become more resistive with increasing Sn content in fluoride-containing solution.