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MM: Fachverband Metall- und Materialphysik
MM 3: Topical Session: Interface-Controlled Microstructures: Mechanical Properties and Mechano-Chemical Coupling - Segregation and Embrittlement I
MM 3.1: Topical Talk
Monday, March 20, 2017, 10:15–10:45, BAR 205
Tensile strength in ab initio simulations: stability of models with planar defects — •Petr Šesták1,2, Miroslav Černý1,2, Monika Všianská1,2, and Mojmír Šob1,2,3 — 1Institute of Physics of Mater., Academy of Sci. of CZ, Brno, CZ — 2Central European Institute of Technology, Brno, CZ — 3Faculty of Science, Masaryk University, Brno, CZ
Ab initio simulations represent an efficient way how to study material properties in those cases where experimental methods are too expensive or impossible to use. However, periodic boundary conditions employed in such simulations impose severe limitations to the size of the simulation cell that can contain just a few hundred atoms at the most. Correct design of appropriate computational cells and simulation models is then a crucial issue in applications of ab initio approaches in simulations of defects.
Here we provide a critical comparison of several models often used for determination of the tensile strength of crystalline systems with planar defects (such as the Σ3 (111), Σ5 (210), Σ5 (310) and Σ11 (311) grain boundaries in fcc nickel) and interfaces in selected composites. Special attention is paid to differences in predictions of individual models and to their sensitivity to the size of the simulation cell (i.e. to different density of defects).