Dresden 2006 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MM: Metall- und Materialphysik
MM 36: Amorphous and Liquid Materials IV
MM 36.4: Vortrag
Donnerstag, 30. März 2006, 17:15–17:30, IFW B
Effect of mechanical deformation on the quasicrystallization of Zr-based metallic glasses — •Sergio Scudino1, Hergen Breitzke2, Klaus Lüders2, Ludwig Schultz3, and Jürgen Eckert1 — 1FB 11 Material- und Geowissenschaften, FG Physikalische Metallkunde, Technische Universität Darmstadt, Petersenstrasse 23, D-64287 Darmstadt, Germany — 2Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany — 3IFW Dresden, Institut für Metallische Werkstoffe, Postfach 270016, D-01171 Dresden, Germany
The devitrification of melt-spun Zr57Ti8Nb2.5Cu13.9Ni11.1Al7.5 glassy ribbon is characterized by the formation of a metastable quasicrystalline phase during the first stage of the crystallization process. To investigate the effect of the mechanical deformation on the formation of quasicrystals, the glassy ribbon was submitted to ball milling. The mechanical treatment drastically affects both the thermal stability and the microstructure evolution upon heating. In particular, primary quasicrystal formation is progressively suppressed with increasing milling time. The results reveal that oxygen, which is introduced during milling, is responsible for the modified crystallization behavior by selectively reacting with zirconium. However, the suppression of quasicrystal formation can be reversed by an appropriate variation of the chemical composition. This indicates that quasicrystal formation from glassy precursors is governed by the chemical composition rather than by the occurrence of a special quenched-in short-range order. This work was supported by the German Science Foundation under grants Ec 111/10-1,2 and Lu 217/17-1.