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M: Metallphysik

M 33: Postersitzung

M 33.7: Poster

Donnerstag, 29. März 2001, 15:15–19:00, Foyer S4, CCH

Boundary integral method for modeling of rapid dendritic growth — •Peter Galenko — Institut für Raumsimulation, Deutsches Zentrum für Luft- und Raumfahrt, D-51170 Köln

The boundary integral method (BLM) is well-established model for prediction of the fractal and dendritic pattern formation and is related to the models of the sharp interface [1]. In the present report, this method for rapid dendritic solidification from supercooled liquid phase in a binary system is developed. In order to model the rapid solidification, a physical description and mathematical formulation is based on the model which takes into account the deviation from local equilibrium at the interface and in bulk phases [2-4]. A main attention in modeling is paid to the examination of the influence of anisotropy energy on the selection of the structure of a free-growing dendrite. As it follows from the results obtained in the modeling, with the decreasing of the anisotropy of surface energy the transition from a smooth needle-like dendrite to a branching dendrite occurs. As the anisotropy vanishes, the dendrite has the oscillating tip velocity and the tip of the dendrite tends to a splitting phenomenon. These results obtained in the modeling confirm the outcomes of the interfacial wave theory [5] in accordance with which there is a critical number for anisotropy lower of which the oscillated dendrite is predicted instead of the steady-state smooth needle.
This work was made possible due to support from the Alexander von Humboldt Foundation, No. IV RUS 1068584.
1. Y. Saito, G. Goldbeck-Wood, H. Müller-Krumbhaar, Phys. Rev. A38 (1988) 2148.
2. P. Galenko, Phys. Lett. A 190 (1994) 292.
3. P. Galenko, S. Sobolev, Phys. Rev. E 55 (1997) 343.
4. P.K. Galenko, D.A. Danilov, Phys. Lett. A 235 (1997) 271.
5. J.J. Xu, Interfacial Wave Theory of Pattern Formation (Springer, Berlin, 1998).