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MM: Fachverband Metall- und Materialphysik
MM 15: Poster session I
MM 15.11: Poster
Monday, March 7, 2016, 18:00–20:00, Poster B3
An ab initio high throughput approach to identify Mg-alloys with exceptionally high yield strength — Zongrui Pei1, 2, Duancheng Ma1, •Martin Friák3, 1, 2, Bob Svendsen1, 2, 4, Dierk Raabe1, and Jörg Neugebauer1 — 1Max-Planck-Institut für Eisenforschun, GmbH, Düsseldorf, Germany — 2Aachen Institute for Advanced Study in Computational Engineering Science (AICES), RWTH Aachen, Aachen, Germany — 3Institute of Physics of Materials, Brno, Czech Republic — 4Material Mechanics, Faculty of Georesources and Materials Engineering, RWTH Aachen, Aachen, Germany
Using ab initio calculations and symmetrized plane waves, we analyze the basal-plane generalized stacking fault energies in pure Mg and Mg-Y alloys and show that the knowledge of energies of only five specific points is sufficient to accurately predict the core structures and Peierls stresses of ⟨a⟩-type edge dislocations in these alloys. Our five-point approach substantially reduces the computational cost related to the Peierls-Nabarro (PN) model and allows for a high-throughput application of the PN model to study Peierls stress changes in Mg upon alloying. We employ our approach to study Mg binary alloys containing nine rare-earth (RE) and 11 other solutes. Based on the Peierls stresses of these 20 Mg alloys calculated from the Peierls-Nabarro model, the solutes are divided into three groups according to the dislocation core structure, the magnitude of Peierls stress, and their either strengthening or softening effect (Phys. Rev. B 92 (2015) 064107).