Dresden 2006 – scientific programme

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MM: Metall- und Materialphysik

MM 35: Growth

MM 35.1: Talk

Thursday, March 30, 2006, 14:45–15:00, IFW B

Investigation of the initial transient in directional solidification of a binary AlCu alloy — •Anne Drevermann, Nils Warnken, Laszlo Sturz, and Gerhard Zimmermann — ACCESS e.V., Intzestr. 5, 52072 Aachen

For the formation of microstructures the initial transient, i.e. the very beginning of solidification, is of major relevance. At this stage a complex interaction between the velocity of the solidification front, the concentration pile-up and the temperature gradient takes place. In this work these three main variables and their coupling are investigated in experiments and numerical simulations.

Directional solidification experiments are carried out thermosolutally stable in a Bridgman-Stockbarger furnace with cylindrical Al-1.3wt.%Cu samples. During solidification the solidification velocity and the temperature profile are measured insitu while the concentration profile is determined afterwards in the processed sample by SEM/EDX analysis.

Numerical simulations were performed according to the Coriell model and with the phase field method. The Coriell simulations consider thermal diffusion in the liquid and the solid and solutal diffusion in the liquid while the phase field simulations consider only solute diffusion. The calculated transient solidification velocities and concentration profiles are in good agreement with the experimental results.