Berlin 2015 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 53: Interfaces II: Deformation and Motion
MM 53.1: Talk
Thursday, March 19, 2015, 11:45–12:00, H 0107
Atomistic simulation of a severe plastic deformation-induced "high-energy" state of grain boundaries — •Lisa Neier1, Sergiy Divinski1, Anantha Padmanabhan2, and Gerhard Wilde1 — 1Institut für Materialphysik, Westfälische-Wilhelms-Universität, 48149 Münster — 2University of Hyderabad, India
A comparison of microstructures and properties in materials subjected to the later stages of severe plastic deformation (SPD) or steady-state superplastic flow indicates several unexpected similarities especially with respect to the interface response on the deformation, such as grain boundary (GB) sliding events, which lead to a suppression of dislocation activity. Making use of this idea, we propose to describe the experimentally observed "high-energy" (or "non-equilibrium") state of general high-angle GBs in SPD-processed materials in terms of the concept of shear localization in the interfaces. For this purpose, oblate spheroids of a few atomic diameters size have been chosen as the basic units of sliding. By performing atomistic simulations of these special grain boundaries, their response to deformation is analysed. Different properties, as e.g. the coupling of grain boundary motion in normal direction to a shear deformation parallel to the grain boundary or the grain boundary stiffness and the local shear modulus are calculated and compared to those of relaxed high angle grain boundaries.