Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 17: SYM Phase Transformations in Metallic Melts VI

MM 17.2: Vortrag

Dienstag, 26. Februar 2008, 11:45–12:00, H 1058

Elastic effects on phase transitions in multicomponent alloys — •Denis Pilipenko, Robert Spatschek, Efim Brener, Heiner Mueller-Krumbhaar, and Clemens Mueller-Gugenberger — Institut für Festkörperforschung, Forschungszentrum Jülich, 52425Jülich, Germany

We report on our activities concerning the influence of elastic effects on multicomponent alloys, which can lead to long-range interactions and the appearance of unexpected dynamical behaviors. We present a continuum theory to describe elastically induced phase transitions between solid and melt phases, which is simulated both by phase field and sharp interface methods. For the particular case of diffusionless phase transitions in solids, where structural and density differences provoke significant strain effects, we predict the macroscopic growth in a strip geometry, which can lead to the emergence of twin boundaries. In the limit that one phase is very soft, we obtain a self-consistent macroscopic model for fast fracture processes, which is based on the Asaro-Tiller-Grinfeld instability. Here we demonstrate that sharp-interface and phase field predictions are in very good agreement despite the large lengthscale gaps that are intrinsic to this problem. Finally, we briefly present recent results concerning the diffusion-limited propagation of a melt phase along an inter-phase boundary and melting in eutectic and peritectic systems.