Berlin 2005 – wissenschaftliches Programm

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M: Metallphysik

M 50: Grenzfl
ächen II

M 50.1: Vortrag

Dienstag, 8. März 2005, 16:30–16:45, TU H2038

Monte Carlo Simulation of Relaxation Processes in Grain Growth — •Dana Zöllner and Peter Streitenberger — Otto-von-Guericke-Universität Magdeburg, Institut für Experimentelle Physik, Abteilung Materialphysik, PF 4120, D-39016 Magdeburg

A modified Monte Carlo Potts Model algorithm for single-phase normal grain growth is presented, which allows one to simulate the coarsening of the microstructure of very large grain ensembles in two and three dimensions. The temporal development of the simulated 2D and 3D grain structures exhibit, after an initial period of time, a scaling state that is characterized by a self-similar grain size distribution. A modified mean-field theory based on topological grain size correlations is presented, which yields self-similar grain size distributions that are in excellent agreement with the simulated grain structures in the scaling state. The emphasis of the present work lies on the relaxation process to the scaling state. An algorithm is implemented which allows one to construct the spatial grain structure for a given grain size distribution. Different initial grain structures characterized by different initial grain size distributions are subjected to grain growth via the Monte Carlo Potts Model simulation. The relaxation process to the self-similar scaling state is studied by following the time development of quantities like the average grain size, the variance of the grain size distribution and topological correlations. It is tested whether the relaxation process can be described by time laws such as the stretched exponential form