An additively manufactured magnesium-aluminium alloy withstands seawater corrosion

Date

2022-04-20

Authors

Zeng, Zhuoran
Choudhary, Sanjay
Esmaily, Marco
Benn, Felix
Derra, Thomas
Hora, Yvonne
Kopp, Alexander
Allanore, Antoine
Birbilis, Nick

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Journal ISSN

Volume Title

Publisher

Nature Publishing Group

Abstract

Magnesium, the lightest structural metal, has inherently poor corrosion resistance. In this study, we developed a magnesiumaluminium Mg-10.6Al-0.6Zn-0.3Mn alloy, additively manufactured by laser powder bed fusion. We reveal that this alloy has a record low degradation rate amongst all magnesium alloys in practically relevant corrosive solutions, and it even withstands seawater corrosion. As tested by a number of methods, the alloy shows even more enhanced passivation with longer immersion periods. The alloy surface following immersion maintained a nearly corrosion-free appearance and was determined to have a thin aluminiumcontaining surface film, due to surface enrichment of aluminium from the supersaturated matrix. Aluminium enrichment near the sample surface was also observed when the sample is immersed in phosphoric acid or exposed to atmosphere at room temperature. This study demonstrates the prospects for additively manufactured ultra-lightweight magnesium structure with outstanding corrosion resistance.

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Citation

Source

npj Materials Degradation

Type

Journal article

Book Title

Entity type

Access Statement

Open Access

License Rights

Creative Commons Attribution 4.0 International License

DOI

10.1038/s41529-022-00241-5

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