Investigation of dealloying by ultra‐high‐resolution nanotomography. (26th November 2012)

• Record Type: Journal Article
• Authors: Hashimoto, T.; Curioni, M.; Zhou, X.; Mancuso, J.; Skeldon, P.; Thompson, G. E.
• Is Part Of: Surface and interface analysis. Volume 45:Number 10(2013:Oct.)
• Page Start: 1548
• Page End: 1552
• Publication Date: 2012-11-26
• Subjects: Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Thin films -- Periodicals; 541.33
• DOI: 10.1002/sia.5176
• Languages: English
• ISSNs: 0142-2421

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>Sequential sectioning and sequential imaging by scanning electron microscopy have been employed to obtain three‐dimensional images of an AA2024‐T3 aluminium alloy after exposure to sodium chloride solution. The three‐dimensional arrangement of intermetallic particles within the alloy was disclosed, indicating that groupings of intermetallics are preferential sites for corrosion initiation due to the combined presence of defects such as cracks or voids and local differences in electrochemical potential. Three‐dimensional imaging enabled the study of the dealloying process occurring on the S‐phase particles (Al–Cu–Mg) during corrosion, revealing the details of a copper‐rich sponge‐like structure. Initially, dealloying proceeds by initial formation of a copper‐rich nanoporous layer containing significant amounts of residual aluminium and magnesium. Subsequently, the layer dealloys further, increasing the free volume of the porous structure. At later stages of dealloying, some copper metal clusters detach from the substrate and oxidize. Copyright © 2012 John Wiley &amp; Sons, Ltd.</p> </abstract>