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MM: Fachverband Metall- und Materialphysik
MM 52: Topical Session: In Situ and Multimodal Microscopy in Materials Physics II
MM 52.6: Talk
Thursday, March 21, 2024, 12:15–12:30, C 130
TEM-analysis of electron beam sensitive anodic aluminum oxides at cryogenic temperatures — •Lydia Daum1, Stefan Ostendorp1, Martin Peterlechner1,2, and Gerhard Wilde1 — 1University of Münster, Münster, Germany — 2Laboratory for Electron Microscopy, Karlsruhe, Germany
While the existence of precipitates and segregations with their related stress fields inside of aluminum alloys are essential for strengthening and achieving desired mechanical properties of these, they pose a challenge in the formation of protective anodic aluminum oxide (AAO) coatings on these. In previous studies, those precipitates are classified into three sections based on their performance during anodization. Due to methodological limitations, the experiments were carried out in enlarged intermetallic areas in binary aluminum alloys [1,2]. Here, we employ different pre-treatments to aluminum alloys, in accordance with industrial standards, to address the effect of precipitates on the formation of the electron beam sensitive AAOs. Previous scanning transmission electron microscopy (STEM) studies have shown that cryogenic temperatures can partially reduce the beam damage in materials such as AAOs [3,4]. Here, we apply multimodal electron microscopy to examine both, chemical and structural changes of the precipitates within the AAO and at the interface to the underlying alloy. This work aims for a better comprehension of AAO growth and its corresponding properties. We try to bridge the properties of aluminum alloys gained by precipitations with the optimization of the formation of AAOs, which can offer valuable insights for industrial applications.
Keywords: Transmission Electron Microscopy; Aluminum Oxides; Cryogenic Temperatures; 4D STEM