Structural evolution and kinetics in Cu-Zr Metallic Liquids

Abstract

The atomic structure of the supercooled liquid has often been discussed as a key source of glass formation in metals. The presence of icosahedrally-coordinated clusters and their tendency to form networks have been identified as one possible structural trait leading to glass forming ability in the Cu-Zr binary system. In this work, we show that this theory is insufficient to explain glass formation at all compositions in that binary system. Instead, we propose that the formation of ideally-packed clusters at the expense of atomic arrangements with excess or deficient free volume can explain glass-forming by a similar mechanism. We show that this behavior is reflected in the structural relaxation of a metallic glass during constant pressure cooling and the time evolution of structure at a constant volume. We then demonstrate that this theory is sufficient to explain slowed diffusivity in compositions across the range of Cu-Zr metallic glasses.

17 pages, 12 figures

Cited by in corpus (8)

• Cooling rate dependence of simulated $\mathrm{C}{\mathrm{u}}_{64.5}\mathrm{Z}{\mathrm{r}}_{35.5}$ metallic glass structure
• Nucleation instability in super-cooled Cu-Zr-Al glass-forming liquids
• Formation and dilatation of shear bands in a Cu-Zr metallic glass: A free volume perspective
• Structure of the glass-forming metallic liquids by ab-initio and classical molecular dynamics, a case study: quenching the Cu60Ti20Zr20 alloy
• Effects of Si solute on the glass formation and atomic structure of Pd liquid
• Simulated Cu-Zr glassy alloys: the impact of composition on icosahedral order
• Atomistic origin of stress overshoots and serrations in a CuZr metallic glass
• Icosahedral order in liquid and glassy phases of cyclohexane