Regensburg 2019 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 27: Methods in Computational Materials Modelling (methodological aspects, numerics)

MM 27.2: Vortrag

Mittwoch, 3. April 2019, 15:15–15:30, H44

Ab initio study of plastic deformation in Fe₂Nb Laves phase — •Alvin Noe Ladines¹, Thomas Hammerschmidt¹, Ali Zendegani², Tilmann Hickel², Ralf Drautz¹, and Joerg Neugebauer² — ¹ICAMS, Ruhr-Universität Bochum, Germany — ²Max Planck Institute for Iron Research, Düsseldorf, Germany

The Fe₂Nb Laves phase is technologically relevant for strengthening advanced stainless steels. An atomistic understanding of the mechanisms of plastic deformation of this phase is lacking. We use density functional theory (DFT) to calculate the generalized stacking faults for various deformation modes. Our calculations reveal that synchroshear is the most energetically favorable deformation mechanism for the C14-Fe₂Nb Laves phase. We further study the influence of intrinsic point defects and alloying elements Al, Si, Cr, Ni, Mo and Zr on the energy of the stacking faults. Vacancies tend to lower the energy barrier for synchroshear deformation, while anti-site defects do not have a systematic effect on stacking fault energies. The alloying elements are shown to soften the C14-Fe₂Nb Laves phase.