Open AccessEditors’ Choice—Dealloying-Driven Cerium Precipitation on Intermetallic Particles in Aerospace Aluminium Alloys
Author(s) -
Ali Kosari,
Majid Ahmadi,
F.D. Tichelaar,
Peter Visser,
Yaiza González-García,
H.W. Zandbergen,
Herman Terryn,
J.M.C. Mol
Publication year - 2021
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abf50d
Subject(s) - intermetallic , cerium , materials science , metallurgy , corrosion , microstructure , aluminium , precipitation , chemical engineering , alloy , physics , meteorology , engineering
Cerium-based compounds have been studied for decades as non-toxic candidates for the protection of aerospace aluminium alloys (AAs) like AA2024-T3. However, the complex heterogeneous microstructure of these alloys has hindered a thorough understanding of the subsequent stages of corrosion protection provided by this class of inhibitors. Thus, this work is devoted to unravelling the interaction mechanisms of different intermetallic particles (IMPs) in AA2024-T3 with cerium nitrate at the nanoscopic scale. This has been fulfilled through detailed top-view and cross-sectional analytical TEM investigations along with electrochemical evaluations. In line with our recent findings, we here report dealloying of IMPs as the main factor governing the rate of local cerium precipitation in contrast to micro-galvanic corrosion between IMPs and the surrounding matrix. Furthermore, we discuss a connection between the electrochemical response of the AA2024-T3 system and the morphological and compositional evolutions of individual IMPs including Al 2 CuMg, Al 2 Cu, Al 7 Cu 2 Fe(Mn) and Al 76 Cu 6 Fe 7 Mn 5 Si 6 at different stages of a 96-h exposure.