Berlin 2005 – wissenschaftliches Programm
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M: Metallphysik
M 14: Wachstum
M 14.2: Vortrag
Freitag, 4. März 2005, 15:00–15:15, TU H2038
The size distribution induced by normal grain growth is lognormal in shape—fact or fiction? — •Carl E. Krill III1, Max Ziehmer2, and Lukas Helfen3 — 1Materials Division, Albert-Einstein-Allee 47, University of Ulm, D-89081 Ulm — 2FR 7.3 Technical Physics, Geb. 43B, University of the Saarland, D-66123 Saarbrücken — 3ESRF, BP 220, F-38043 Grenoble Cedex
Experimental investigations of normal grain growth invariably find that the distribution of grain sizes can be approximated by a lognormal function. Computer simulations of the same process, however, predict a far more symmetrical distribution shape, regardless of the underlying algorithm used to model the migration of grain boundaries. One possible explanation for this discrepancy arises from the manner in which the grain size is determined: in experiment, one generally relies on the cross-sectional area evident in a two-dimensional section passing through the grain, whereas one has access to the full three-dimensional grain volume during a simulation. By applying 2-D and 3-D grain-size analyses to identical polycrystalline microstructures, we have attempted to assess the extent to which stereological factors contribute to the apparent shape of the size distribution generated by normal grain growth. Results obtained using experimental coarsening data are compared to those of a large-scale grain-growth simulation, with the goal of determining whether the size distribution really differs in the two cases.