Anti-corrosion mechanism of epoxy-resin and different content Fe₂O₃ coatings on magnesium alloy

Abstract

In this study, anti-corrosion coatings were prepared and coated successfully on magnesium alloy substrates by mixing nanopowders, solvent, curing agent with epoxy resin. The effect of the amount of iron trioxide (Fe₂O₃) on the adhesion strength and corrosion resistance on magnesium alloy was investigated with standard protocols, and electrochemical measurements were also made in 3.5 wt.% NaCl solutions. The surface morphology and corrosion mechanism after corrosion tests was characterized using FESEM analysis. Nanoparticles in matrix acted as filler, and interstitial cross-linked spaces and other coating artifacts regions (micro cracks and voids) would all affect the anti-corrosion properties of coating. The results showed the proper powder content not only provided adhesion strength to these coatings but also improved obviously their anti-corrosion. Hydrogen bound to the amine nitrogen (¹N) could take part in the curing process rather than hydrogen of the amide site due to the smaller ΔG and the more stable configuration.

Keywords

magnesium alloy / corrosion / iron trioxide / anti-corrosion mechanism

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Acknowledgements

This research was supported by SDUST Research Fund (Grant No. 2014TDJH104), and we appreciate Prof. Rong-chang Zeng due to offering part magnesium alloys and some good advice for this research.

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2016 Higher Education Press and Springer-Verlag Berlin Heidelberg