Localized Atmospheric Corrosion of Magnesium-Aluminum Alloys Produced by Semisolid Casting: A 2D and 3D Investigation
Name
Manuscript_Microscopy Investigation of Localized Corrosion (1).pdf
Description
Accepted version
Size
2.6 MB
Format
Adobe PDF
Checksum (MD5)
0a713ac0abe6cdd53bf5fd7d5b64bd10
Author(s)
Shahabi-Navid, M.
Halvarsson, M.
Svensson, J.E.
Allanore, Antoine
Birbilis, N.
Johansson, L.G.
Esmaily, M.
Date Issued
November 2020
Journal
Corrosion
Publisher
NACE International
Citation
Shahabi-Navid, M. et al. "Localized Atmospheric Corrosion of Magnesium-Aluminum Alloys Produced by Semisolid Casting: A 2D and 3D Investigation." Corrosion 77, 2 (November 2020): 242–253. © 2021 NACE International
Version
Author's final manuscript
Abstract
The localized corrosion of the two magnesium-aluminum alloys AM50 and AZ91 produced by a semisolid casting method was investigated under atmospheric corrosion conditions, in the presence of NaCl. Gravimetry confirmed the beneficial effect from ambient levels of carbon dioxide (CO₂) in suppressing corrosion through the formation of magnesium hydroxy carbonates. Both 2D and 3D characterization revealed that ambient CO₂ has a strong influence on the morphology and rate of localized corrosion. In CO₂-free atmosphere, the alloys suffered localized corrosion resulting in clustered and interconnected cavities that extended deep into the material. In contrast, corrosion in the presence of ambient levels of CO₂(400 ppm) resulted in evenly distributed shallow corrosion sites. The results indicate that CO₂ neutralizes the cathodic areas resulting in diminished cathodic activity and inhibiting NaCl(aq) droplet coalescence.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.5006/3655
