Regensburg 2019 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 16: Methods in Computational Materials Modelling (methodological aspects, numerics)

MM 16.10: Talk

Tuesday, April 2, 2019, 12:45–13:00, H45

Determining mobilities and anisotropic grain boundary energies from MD simulations of shrinking grains — •Adrian A. Schratt and Volker Mohles — ICAMS, Ruhr-Universität Bochum

A new technique to determine average grain boundary (GB) mobilities and energies for arbitrary grain misorientations from molecular dynamics (MD) simulations has been developed. The shrinkage velocity of a cylindrical or spherical grain (2D/3D) allows to calculate the reduced mobility of the GB. From an isotropic model for the capillary driving force we can also derive the average energy of the GB during the shrinkage. The connection between the shrinkage velocity, the GB stiffness and the mobility is exploited to compute the latter. The technique is free of possible artefacts from synthetic driving forces as the GB is only driven by its curvature. In addition, information on the anisotropy of the GB energy can be derived: during shrinkage, the initially cylindrical or spherical shape becomes slightly facetted. This can be expressed as an occurrence frequency of GB plane orientations, which in turn can be used to formulate the GB energy as a function of the plane normal direction. This can be used for instance in mesoscopic models of GB motion.