Dresden 2014 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 34: Poster Session
MM 34.1: Poster
Dienstag, 1. April 2014, 18:00–20:00, P4
Simulation of abnormal grain growth in nanocrystalline materials — •Mingyan Wang1, Jules Dake1, Rainer Birringer2, and Carl Krill1 — 1Institute of Micro and Nanomaterials, Ulm University, Germany — 2FR 7.3 Technical Physics, University of the Saarland, Germany
Despite the rarity suggested by its name, abnormal grain growth (AGG) appears to be a common mode of coarsening in nanocrystallinespecimens, observed in a wide variety of materials prepared by a range of synthesis routes. During AGG, a subpopulation of grains manifests rapid growth, leading to grain volumes that are not only much larger than those of their neighbors, but also sometimes highly irregular in shape. The latter observation suggests that, in certain cases, AGG might proceed by a kind of percolation phenomenon occurring on a ``grid'' defined by the initial ensemble of grains. We have investigated this possibility by extending a conventional phase field algorithm for simulating grain growth to include selection rules for percolation. The resulting simulated abnormal grains are strikingly similar in shape to their experimental counterparts. By quantifying the comparison between simulation and experiment, we hope to shed light on at least one of the underlying physical mechanisms for AGG in nanocrystalline materials.