Oxidation of a Zr46Cu46Al7Gd1 bulk metallic glass detected via optical characterizations

Abstract

Oxidation of metallic glasses has been shown to be different from crystalline alloys due to the disordered atomic structures and far-from-equilibrium state, and quick characterization is required to reveal their early stage oxidation. In this study, we investigated the oxidation behavior of a Zr46Cu46Al7Gd1 bulk metallic glass by measuring the changes of optical constants via spectroscopic ellipsometry. Characterizations with X-ray diffraction, scanning electron microscopy, and thermogravimetric analyzer confirmed that the changes of pseudo-optical constants reflected not only the onset temperature at which the alloys underwent obvious oxidation, but also the subtle oxidation which was tedious to characterize. Our study suggests a more efficient and accurate approach to understand the oxidation of metallic glasses with temperature, time and compositions.