SKM 2023 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 37: Topical Session: Defect Phases II

MM 37.3: Vortrag

Donnerstag, 30. März 2023, 11:00–11:15, SCH A 216

Understanding corrosion phenomena based on surface phase diagrams for Mg alloys in contact with water — •Jing Yang, Mira Todorova, and Jörg Neugebauer — Max-Planck-Insitut für Eisenforschung GmbH, Max-Planck-Strasse 1, D-40237 Düsseldorf, Germany

Defect phases formed at alloy surfaces and interfaces govern their chemical and mechanical behavior. Constructing phase diagrams from ab initio modeling provides valuable information for understanding the microscopic mechanisms of surface and interface processes. In this work, we apply this approach to study the aqueous corrosion of magnesium alloyed with Al and Ca, an important structural material for the automotive and aerospace industries. Constructing defect phase diagrams for the passive film formed on the magnesium surface, we analyze how the Al and Ca alloying atoms evolve during the corrosion process and how they impact the corrosion resistance of the magnesium alloy. In particular, we resolve the cause of Al enrichment in the passive film, which has been recently observed in experiment. Based on these examples we discuss how defect phase diagrams can help us to better understand microscopic chemical processes under realistic conditions.