Regensburg 2022 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 20: Computational Materials Modelling: HEA, Alloys & Nanostructures

MM 20.10: Vortrag

Mittwoch, 7. September 2022, 12:45–13:00, H44

Ab initio investigation of Mg alloy corrosion in water — •Jing Yang, Mira Todorova, and Jörg Neugebauer — Max-Planck-Insitut für Eisenforschung GmbH, Düsseldorf, Germany

Magnesium alloys have great potential as structural materials for the automotive and aerospace industries, as well as bio-implants due to their low density and non-toxic nature. However, intrinsically poor ductility and poor corrosion resistance limit their practical application. In this work, we focus on the solid solution of Al and Ca in Mg, an alloying system which has shown improved ductility and corrosion resistance. In particular, we elucidate the effect of Al and Ca alloying on the aqueous corrosion process of Mg metal by ab initio molecular dynamics simulation of the metal/water system. We analyze the segregation behavior of the alloying elements, their impact on the interfacial water structure and dynamics, and the subsequent implication on corrosion kinetics. By combining our DFT calculations with thermodynamics, we construct interface phase diagrams for the Mg-Al-Ca system to elucidate the influence of the environment on surface structure and composition. We consider both implicit and explicit water calculations, which allows us to analyze the impact the water-modelling approach has on the constructed interface phase diagrams. We show that such ab initio molecular dynamics studies strongly improve our understanding on microscopic corrosion processes at realistic conditions.