Regensburg 2025 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 26: Topical Session: Thermophysical Properties of Bulk Metallic Glasses and Bulk Metallic Glass-forming Liquids
MM 26.2: Vortrag
Donnerstag, 20. März 2025, 10:30–10:45, H10
Structure and dynamics of Ni-Nb alloy melts upon sulfur addition — Nicolai Grund1, Dirk Holland-Moritz1, Saba Khademorezaian2, Lucas P. Kreuzer1,3, Nico Neuber4, Lucas M. Ruschel4, Hendrik Voigt2, Johanna Wilden1, •Fan Yang1, Sergiy Divinski2, Ralf Busch4, Andreas Meyer1, and Gerhard Wilde2 — 1Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Köln, Germany — 2Institute of Materials Physics, University of Münster, Münster, Germany — 3Heinz Maier-Leibnitz-Zentrum, Technische Universität München, Garching, Germany — 4Chair of Metallic Materials, Saarland University, Saarbrücken, Germany
We investigated the change in the structure and dynamics of a Ni-Nb bulk metallic glass upon sulfur addition on microscopic and macroscopic scales. With the sulfur concentration of 3 at.%, where the composition Ni58Nb39S3 exhibits the best glass forming ability in the investigated sulfur concentration range, both the equilibrium and undercooled melt dynamics remain almost unchanged. Only in the glassy state sulfur seems to result in less decoupled mass transport to the viscosity of the undercooled liquid, where the Ag tracer diffusion coefficient is slower in the ternary alloy. With the structural disorder introduced by alloying sulfur, the improved glass forming ability is attributed to geometrical frustration, where crystal nucleation requires a depletion of sulfur and hence long range diffusion, as long as no primary sulfur-containing crystalline phase is involved.
Keywords: sulfur containing alloys; bulk metallic glasses; structural-dynamics studies; neutron and X-ray scattering