1. Mechanism of Mn on inhibiting Fe-caused magnesium corrosion.
- Author
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Yang, Lei, He, Shouzhen, Yang, Chao, Zhou, Xiaorong, Lu, Xiaopeng, Huang, Yuanding, Qin, Gaowu, and Zhang, Erlin
- Subjects
MAGNESIUM alloys ,MAGNESIUM ,SALT ,IRON-manganese alloys ,ELECTROLYTIC corrosion ,ALLOYS - Abstract
In the present study, to understand the mechanism of Mn on inhibiting Fe-caused Mg corrosion, the corrosion behaviour of commercial pure Mg and Mg-6Mn alloy in 0.6 M NaCl solution is investigated. It is found that in Mg-6Mn alloy, Fe impurity is incorporated into Mn to form Mn (Fe) phase with Fe as solid solute. The initial galvanic corrosion cannot be reduced through converting Fe-rich phase to Mn (Fe) phase, since Mn (Fe) phase also has relatively strong cathodic activity and has much larger volume fraction than Fe-rich phase. However, the cathodic activation behaviour of pure Mg is inhibited. The cathodic activity even decreases for Mg-Mn alloy with increased exposure time, due to the reduced cathodic HER at the Mn (Fe) particles. Mn can be oxidized at the OCP of Mg-6Mn alloy, resulting in relatively dense Mn-rich corrosion film on particle surface, which separates the particle from the electrolyte and, consequently, inhibits HER. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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