Dresden 2014 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 56: Liquid and Amorphous Metals IV
MM 56.2: Vortrag
Donnerstag, 3. April 2014, 11:45–12:00, IFW A
Investigations of temperature-time-transformation behavior of bulk glass forming alloys — •Stefanie Koch1,2, Dieter M. Herlach1,2, and Markus Rettenmayr3 — 1Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt, 51170 Köln, Germany — 2Institut für Experimentalphysik IV, Ruhr-Universität Bochum, 44780 Bochum, Germany — 3Otto-Schott-Institut für Materialforschung, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany
Isothermal crystallization studies were performed on Zr-based bulk glass forming alloys in the undercooled liquid region between the glass transition and liquidus temperature. The resulting temperature-time- transformation (TTT) diagram for crystallization is used to identify the primary factors influencing their glass-forming ability.
To prevent heterogeneous nucleation on container walls, levitation techniques are used. In this work electrostatic levitation (ESL) is used to melt and undercool samples. Containerless processing is an effective tool for undercooling melts far below their equilibrium melting temperatures. In case of ESL samples in a diameter of 3mm are processed in ultra-high vacuum.
At first an effect of the temperature from which the melt is cooled is observed on the crystallization behavior for Zr-based bulk metallic glasses. A critical temperature is found above which there is an increase in the undercooling and the crystallization time. To determine the TTT diagram, isothermal experiments were performed.
This work is supported by DLR Space Management.