Regensburg 2010 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 56: Topical Session Growth Kinetics VI

MM 56.5: Talk

Thursday, March 25, 2010, 16:30–16:45, H4

Conditions for the occurrence of Abnormal Grain Growth studied by a 3D Vertex Dynamics Model — •Melanie Syha and Daniel Weygand — KIT, Institut für Zuverlässigkeit von Bauteilen und Systemen, Kaiserstr. 12, 76128 Karlsruhe

The three dimensional (3D) vertex dynamics model presented in [1,2] has proven to be suited to model the coarsening of systems of up to several thousand grains with an excellent agreement to the MacPherson/Srolovitz relation for the volume change rate. Now this model is applied to investigate the phenomenon of Abnormal Grain Growth (AGG) in SrTiO3.Although the effect of AGG in perovskite materials in absence of pinning is covered by several investigations [3,4] the underlying mechanisms are still not well understood.In contrast to classical mean field approaches which often assume special but uniform GB properties for the abnormally growing grain of size r, the present study focusses on the role of GB mobility and energy variation, such as inclination dependencies, on the onset of AGG. [1] M. Syha, D. Weygand, A generalized vertex dynamics model for grain growth in three dimensions, accepted for publication, Modeling Simul. Mater. Sci. Eng. [2] D. Weygand, Y. Bréchet, J. Lépinoux, W. Gust, Three dimensional grain growth: A vertex dynamics simulation,Phil. Mag. B 79 (1999) 703-16 [3] T. Sano, G. Rohrer, Experimental evidence for the Development of Bimodal Grain Size Distributions by the Nucleation-Limited Coarsening Mechanism, J. Am. Ceram. Soc. 90 (2007) 199-204 [4] C. Bae, J. Park, Y. Kim, H. Jeon, Abnormal Grain Growth of Niobium-Doped Strontium Titanate, J. Am. Ceram. Soc. 81 (1998) 3005-09