The Correlation among the Atomic Structure, Electronic Valence Band and Properties of Zr-Cu-Al-Ag Bulk Metallic Glasses

Abstract

Investigating the relationship between the glass-forming ability (GFA), mechanical properties, and structure of metallic glasses is crucial to understanding the nature of the metallic glass state. In this study, the correlation among the atomic structure, electronic valence band, and properties have been studied using Zr50Cu44.5−xAl5.5Agx (x = 0, 1.5, 3 at.%) bulk metallic glasses (BMGs). The results reveal that through the micro-addition of Ag, the GFA of Zr50Cu44.5Al5.5 BMG can be enhanced; meanwhile, the critical diameter of Zr50Cu44.5Al5.5 glass rods increases from approximately 2.5 mm to 5.0 mm with the addition of 3% Ag. Through the addition of Ag, the thermal stability of Zr50Cu44.5Al5.5 BMG is improved, and the proportion of icosahedral-like clusters increases. The plasticity of the Zr50Cu44.5−xAl5.5Agx (x = 0, 1.5, 3 at.%) BMGs decreased from 4.6% to 0.8% with the addition of Ag. The valence band spectrum of the Zr50Cu44.5−xAl5.5Agx (x = 0, 1.5, 3 at.%) BMGs indicates that with the addition of Ag, the p-d hybridization near the Fermi level is enhanced, and the binding energy will move to a lower value.