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Abstract
Quasi-in-situ transmission electron microscopy was employed to study dissolution associated with η-phase (Mg(Zn,Al,Cu)2) precipitates in a Cu-containing 7xxx Al-alloy. Two distinct η-phase chemistries, with Cu to (Zn+Mg+Al) ratios ∼0.12 and ∼0.2, were studied in 0.01 M NaCl at pH 6 and 2. In near-neutral NaCl, both η-phase precipitates exhibited ‘duplex’ behaviour, i.e., they were primarily more noble with respect to the surrounding Al-matrix, causing matrix dissolution, and simultaneously established nanoscopic active sites within the noble precipitate itself by generating nanoscale pits. Conversely, η-phase precipitates rapidly dealloyed in acidic NaCl, forming nocrystalline Cu remnants containing twins, which subsequently caused Al-matrix dissolution.
Document Type
Article
Publication Date
2025
Digital Object Identifier (DOI)
https://doi.org/10.1016/j.corsci.2025.113026
Repository Citation
Kairy, S. K.; Wu, Y.; Turk, S.; Shekhter, A.; Buchheit, Rudolph; and Birbilis, N., "Clarifying the role of η-phase with varying chemistry on localised corrosion of a Cu-containing 7xxx Al-alloy by quasi-in-situ TEM" (2025). Chemical and Materials Engineering Faculty Publications. 122.
https://uknowledge.uky.edu/cme_facpub/122
Notes/Citation Information
0010-938X/Crown Copyright © 2025 Published by Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.