Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 26: Computational Materials Modelling V - Fracture and Other Failure Mechanisms
MM 26.4: Vortrag
Dienstag, 27. März 2012, 12:45–13:00, TC 006
Ab-initio Study on Liquid Metal Embrittlement in the Fe/Zn System — •Klaus-Dieter Bauer1, Mira Todorova2, Kurt Hingerl1, and Jörg Neugebauer2 — 1Center for Surface and Nanoanalytics, Johannes Kepler University Linz, Austria — 2Department for Computational Materials Design, Max-Planck-Institut für Eisenforschung, Düsseldorf, Germany
In the manufacturing of high quality steels products, processing steps and costs can be saved by hot-forming (already) coated steel plates. For galvanized sheets however, a degradation of workpieces’ quality is observed, caused by Liquid Metal Embrittlement (LME) of the steel bulk coming in contact with the liquid zinc phase. To get insight into the mechanism of LME in the Fe/Zn system we perform density-functional-theory calculations, considering the [111]Σ 3 and [110]Σ 5 tilt grain boundaries in bcc iron (ferrite). Investigating the applicability of the Griffith model, we compare the interface energies of the grain boundaries and associated surfaces for different Zn coverages. Our results show Zn wetting to stabilize the grain boundaries, and even stronger the associated surfaces, yet not sufficiently to cause spontaneous surface formation. This is compatible with the outcome of experiments performed at Voestalpine AG.