Regensburg 2007 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 12: Growth
MM 12.4: Vortrag
Montag, 26. März 2007, 17:00–17:15, H6
Modeling of equiaxed solute-controled dendrites which interact via a temperature* field — •Matthias Jurgk1, Heike Emmerich2, and Ricardo Siquieri2 — 1Max-Planck-Institut für Physik komplexer Systeme, Dresden, Germany — 2Institut für Gesteinshüttenkunde, Rheinisch-Westfälische Technische Hochschule, Aachen, Germany
A fundamental challenge in the modeling of solidification processes arises from the many different length scales, on which important sub-processes take place.
We discuss a model for dendritic microstructures in the solidification of binary alloys. For most alloys the transport scales of solute diffusion and heat diffusion differ by several orders of magnitude. The two-scale model, which we discuss, includes both these transport scales in an efficient manner and enables us to study a whole array of equiaxed dendrites, whose microstructure morphology is controled by the slow solute transport but which interact with each other via the fast temperature transport.
One crucial parameter of the model is the ratio of both transport scales. Our numerical investigations of the model indicate the existence of two different growth regimes of the dendrites in dependence on the ratio of the transport scales. Another important parameter in the model is the density of the dendritic nuclei in the considered domain. We will also discuss the influence of this density on the growth dynamics of the dendritic microstructures.