Dresden 2009 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 34: Liquid and Amorphous Metals I

MM 34.7: Vortrag

Mittwoch, 25. März 2009, 16:15–16:30, IFW D

Liquid Phase Separation in Gd-Zr and Gd-Ti Melts — •Steffen Schmitz, Hans-Günther Lindenkreuz, Norbert Mattern, Wolfgang Löser, and Bernd Büchner — IFW Dresden, P.O. Box 270116, D-01171 Dresden, Germany

Phase-separated metallic glasses can be formed in complex alloys involving binary terminal systems with both, negative and positive enthalpy of mixing. The miscibility gaps of Gd-Zr and Gd-Ti melts are determined by electromagnetic levitation experiments. If Gd-Ti melts are undercooled below the binodal line samples exhibit the typical coarse phase separated microstructures. On contrary, in Gd-Zr samples quenched on a Cu-substrate both of the two primary phases, i.e. Gd and Zr, occurred in the matrix simultaneously with the eutectic microstructure. Therefore the existence of a metastable miscibility ap is supposed. The findings are compared with CALPHAD calculations of the binary phase diagrams. The consequences for the formation Gd-Zr-Cu and Gd-Ti-Cu metallic glasses by rapid quenching techniques showing phase separation on the nanometre scale are briefly discussed.