Dresden 2006 – wissenschaftliches Programm

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MM: Metall- und Materialphysik

MM 35: Growth

MM 35.6: Vortrag

Donnerstag, 30. März 2006, 16:00–16:15, IFW B

Suppression of eutectic precipitation in rapid solidification of a binary system — •Peter Galenko and Dieter Herlach — Intitut für Raumsimulation, DLR, 51170 Köln, Germany

Experimental results on rapid solidification for binary systems in a range of eutectic concentration are analysed. Conditions at which eutectic precipitation is suppressed are found. A model for rapid crystal growth in a binary system of eutectic composition is developed. Analytical solutions of the model allow to predict beginning solidification of supersaturated solid solution without eutectic precipitation. It occurs at a solidification velocity equal to solute diffusion speed in bulk liquid. Within this point, a solute diffusion-limited growth is finishing with an onset of diffusionless solidification of the supersaturated solid solution. In such a case, complete solute trapping proceeds and eutectic solidification does not occur. The work was supported by DFG under contract No. He 1601/13.