Localized corrosion induced surface modifications of Al-Cu-Li alloy studied by ToF-SIMS 3D imaging

Meicheng Li , Antoine Seyeux , Frédéric Wiame , Philippe Marcus , Jolanta Światowska (1)

1 IRCP - Institut de Recherche de Chimie Paris

Abstract Three-dimensional (3D) time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging is a promising tool in the analysis of surface modifications of alloy matrix and intermetallic particles induced by localized corrosion due to its good spatial resolution and very high sensitivity to chemical identification especially involving light mass elements like Li. In this paper, ToF-SIMS 3D chemical mapping combined with scanning electron microscopy was performed to study the localized corrosion of Al-Cu-Li alloy (AA2050-T8) in a region around an Al-Cu-Fe-Mn intermetallic particles (IMPs) in 0. 1 M NaCl solution. Initiation of corrosion was locally observed on the IMPs and between IMPs and matrix substrate. Moreover, a modified oxide/hydroxide layer was observed over IMPs compared to the matrix. This new corrosion layer was enriched with chlorides and Cu hydroxides. ToF-SIMS 3D imaging revealed that Li was present over the alloy matrix, while no Li was present over the IMPs in regions where localized corrosion occurred.

Mots clés: ToF-SIMS; three-dimensional (3D) chemical mapping; localized corrosion; Al-Cu-Li alloy; intermetallic particles

Domaines: Chimie analytique; Matériaux

Meicheng Li, Antoine Seyeux, Frédéric Wiame, Philippe Marcus, Jolanta Światowska. Localized corrosion induced surface modifications of Al-Cu-Li alloy studied by ToF-SIMS 3D imaging. npj Materials Degradation, 2021, 5 (1), ⟨10.1038/s41529-021-00170-9⟩. ⟨hal-03433131⟩