In-situ nanoscopic observations of dealloying-driven local corrosion from surface initiation to in-depth propagation. (December 2020)

• Record Type: Journal Article
• Authors: Kosari, A.; Zandbergen, H.; Tichelaar, F.; Visser, P.; Taheri, P.; Terryn, H.; Mol, J.M.C.
• Is Part Of: Corrosion science. Volume 177(2020)
• Publication Date: 2020-12
• Subjects: Aerospace aluminium alloys -- In-situ liquid-phase TEM -- Dealloying -- Pitting corrosion -- Copper redistribution; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.108912
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Dealloying is involved in materials science responsible for fabrication of nanoscale structures beneficially but for corrosion degradations detrimentally. Detailed understanding related to the latter is critical for designing corrosion-resistance alloys and dedicated inhibition systems. Thus, direct nanoscopic observations of nano-structural and compositional evolutions during the process are essential. Here using liquid phase-transmission electron microscopy (LP-TEM), for the first time, we show dynamic evolution of intricate site-specific local corrosion linked to intermetallic particles (IMPs) in aerospace aluminium alloys. To thoroughly probe degradation events, oxidation direction is controlled by purposefully masking thin specimens, allowing for observing top-view surface initiation to cross-sectional depth propagation of local degradations. Real-time capturing validated and supported by post-mortem examinations shows a dealloying-driven process that initiates at IMPs and penetrates into the depth of the alloy, establishing macroscopic corrosion pits. Besides, controversial mechanisms of noble-metal redistribution are finally elucidated.