Berlin 2012 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 21: Microstructure and Phase Transformations II
MM 21.1: Vortrag
Dienstag, 27. März 2012, 10:15–10:30, H 0106
A phase-field simulation of directional solidification in ternary Al-Cu-Ni alloys — •Julia Kundin1, Henning Hörstermann1, Rainer Schmid-Fetzer2, and Heike Emmerich1 — 1Material- und Prozesssimulation, Universität Bayreuth, 95448 Bayreuth, Germany — 2TU Clausthal, Institute for Metallurgy, 38678 Clausthal-Zellerfeld, Germany
A precise calculation of the directional solidification based on a reliable thermodynamic description is carried out in a ternary Al-Ci-Ni alloy. A comprehensive understanding of the interplay between the phases in the three-phase peritectic reaction and in the four-phase transition reaction, and their influence on the nucleation kinetics and the resulting microstructure evolution is of great interest. A three-phase peritectic reaction in a ternary system is no longer invariant but a univariant reaction, which means, the equilibrium compositions of all phases vary with the temperature. For a four-phase reaction L + α → β + γ, there are two product phases, which have an effect on the nucleation. If the product phase β first precipitates via heterogeneous nucleation on the primary phase α, these precipitates of β may be also a potent nucleant for the other product phase γ. The microstructure formation of a ternary Al-Cu-Ni alloy during the directional solidification with a three-phase peritectic reaction and a four-phase transition reaction is simulated by a quantitative multi-phase multi-component phase-field model. The refined thermodynamic description of the system as well as other input data for the phase-field model are discussed.