Berlin 2008 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 17: SYM Phase Transformations in Metallic Melts VI
MM 17.1: Vortrag
Dienstag, 26. Februar 2008, 11:30–11:45, H 1058
Modeling elasticity effects in pattern formation during alloy solidification — Bo Liu1, •Klaus Kassner2, Robert Spatschek3,4, and Clemens Müller-Gugenberger4 — 1AG Mathematische Modellierung, MPI für Marine Mikrobiologie, Bremen — 2Institut für Theoretische Physik, Otto-von-Guericke Universität, Magdeburg — 3Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts, USA — 4Institut für Festkörperforschung, Forschungzentrum Jülich
We have developed a series of phase-field models allowing to simulate various aspects of strain-induced effects on alloy solidification. On the one hand, we include compositionally induced stresses in a phase-field model describing growth of dilute alloys. Special care is taken to obtain a viable thin-interface limit, i.e., we eliminate artificial effects of interface stretching, surface diffusion, and interface dissipation by an appropriate choice of phase-field functions and parameters. Simulations of directional solidification in a parameter range discussed by Spencer et al. [1] in terms of a linear stability analysis reveal oscillatory standing wave modes as the preferred dynamic state. On the other hand, after realizing that past models are flawed, we have created asymptotically correct phase-field models for the simulation of surface diffusion under stress, which may become important in solidification when micro-crack formation plays a role.
B.J. Spencer, P.W. Voorhees, S.H. Davis, G.B. McFadden, Acta metall. mater. 40 1599 (1992).