Regensburg 2010 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 34: Liquid and Amorphous Metals I
MM 34.3: Vortrag
Mittwoch, 24. März 2010, 10:45–11:00, H5
Distribution of oxides in a Zr-Cu-Ni-Al-Nb-Si bulk metallic glass — •Jochen Heinrich1, Frank Mueller2, Ralf Busch1, and Stefan Huefner2 — 1Chair of Metallic Materials, Saarland University, PO Box 151150, 66041 Saarbrücken, Germany — 2Chair of Experimental Physics, Saarland University, PO Box 151150, 66041 Saarbrücken, Germany
The course of oxide presence with distance from the sample surface and bonding partner was studied for the bulk metallic glass with the nominal composition Zr57.9Cu15.4Ni12.7Al10.2Nb2.8Si1 (at%) by X-ray photoelectron spectroscopy (XPS). Investigated specimens are taken from vacuum quench-cast rods subjected to oxidation at room temperature and atmosphere. Binding energies were determined in various depths using ion beam ablation of up to 100 nanometers. XPS spectra confirm oxidation primarily of the pure zirconium and aluminum constituents, all other peaks correspond to metallic bonds. While the surface area shows a passivating zirconia layer a few nanometers thick, oxygen is bonded predominantly with aluminum inside the bulk. Since the concentration of oxygen is a crucial factor in the crystallization behavior of bulk metallic glass forming liquids on basis of oxygen affine metals, so far only high purity materials were thought to be suitable. The findings in this study, however, are promising for alloys with industrial grade elements with sufficient glass forming ability. Comparisons of the alloy with differing oxygen content support the conclusion that aluminum acts as an appropriate scavenger for both adsorbed and large amounts of intrinsic oxygen in zirconium based amorphous metals.