Berlin 2008 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 26: Liquid and Amorphous Metals I

MM 26.4: Vortrag

Mittwoch, 27. Februar 2008, 14:45–15:00, H 0107

Effect of composition on crystallization behavior and viscosity of Zr-based metallic glasses — •Sergio Scudino, Birgit Bartusch, and Jürgen Eckert — IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden, Germany

The variation of Al and Zr drastically affects the crystallization behavior and the viscosity of the melt-spun Zr-Ti-Nb-Cu-Ni-Al glassy ribbons. The devitrification of the ribbons with high Zr or low Al contents is characterized by the formation of a metastable quasicrystalline phase during the first stage of the crystallization process. With increasing Al or decreasing Zr contents the temperature range of stability of the quasicrystals decreases and their formation is progressively hindered. The temperature of the glass transition and the crystallization temperatures related to the crystallization events shift to higher values with increasing Al or decreasing Zr contents. At the same time, the viscosity of the supercooled liquid and the fragility parameter (D) increase, indicating an improved glass forming ability. A clear correlation between fragility parameter and glass transition has been found. This correlation provides a guide for the estimation of D for this particular system when the glass transition is known.