Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 49: Interfaces I: Structure and Segregation
MM 49.5: Vortrag
Donnerstag, 19. März 2015, 11:15–11:30, H 0107
Theoretical strength of Σ5 (210) GB in FCC cobalt with segregated interstitial and substitutional sp-impurities — •Petr Šesták1,2, Miroslav Černý1,2,3, Petr Řehák1,2,3, Monika Všianská1,3, and Mojmír Šob1,3,4 — 1) Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno, Czech Republic — 2Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czech Republic — 3Central European Institute of Technology, Brno, Czech Republic — 4Faculty of Science, Masaryk University, Brno, Czech Republic
Grain boundaries (GBs) determine many mechanical properties of polycrystalline materials, in particular their strength. Moreover, the impurities contained in the material tend usually to segregate at the GBs and thus they can have a strong negative or positive influence on its mechanical characteristics. In this first-principles study we simulate the uniaxial tensile test of FCC cobalt containing the Σ5 (210) tilt GB with segregated sp-impurities. The uniaxial deformation was performed along an axis perpendicular to the GB. The impurities Al, Ga, In, Sn, Sb and Te were considered in substitutional positions at the GB and Si, P, S, Ge, As and Se in interstitial positions. The strength of segregated GBs was compared with the strength of the clean GB. The uniaxial deformation was realized using two different approaches. In the first one the repeat cell was continually optimized during the entire deformation path and in the second one the deformation corresponded to a rigid separation of grains along a defined plane without any cell optimization.