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MM: Fachverband Metall- und Materialphysik
MM 27: Phase Transformations II
MM 27.5: Talk
Wednesday, March 16, 2011, 15:30–15:45, IFW D
On the Growth Behaviour of Individual Grains in Polycrystals — •Dana Zöllner1, Peter Streitenberger1, and Iain Fielden2 — 1Institut für Experimentelle Physik, Abteilung Materialphysik, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, 39106 Magdeburg, Germany — 2Materials and Engineering Research Institute, Sheffield Hallam University, Sheffield, UK
A 3D grain growth model is developed allowing the prediction of the growth history of individual grains. The model - based on a generalised mean-field approach - represents data of 3D grain growth - simulated by a Monte Carlo Potts model algorithm - very well. The parameters from the obtained grain size distribution are then used to calculate an analytic function describing the individual growth history of all grains. A comparison with simulation results of normal grain growth shows good agreements for the temporal development of grain sizes of single grains as well as for the prediction of their life span.
On the other hand, the monitoring of the motion of individual quadruple points and triple junctions in 2D sections of the simulated 3D microstructures shows a highly discontinuous movement. Based on a stochastic grain growth model the diffusivity of the Brownian-like motion can be related to the average growth rate providing a possibility to determine the average growth law of the grain ensemble solely from the stochastic growth behaviour of single grain features.
In addition, the simulation results - compared with real-time in-situ SEM observations of grain growth - show a good qualitative agreement of the temporal movement of grain boundary junctions.