Correlation of the fragility of metallic liquids with the high temperature structure, volume, and cohesive energy

TL;DR

This study links metallic liquids' fragility to their high-temperature structure, volume, and cohesive energy, providing insights for designing metallic glasses based on measurable properties.

Contribution

It establishes a clear connection between liquid fragility and high-temperature structural and volumetric changes, highlighting the role of cohesive energy in metallic liquids.

Findings

Fragility correlates with structural and volumetric changes at high temperatures.

More fragile liquids exhibit larger changes in structure and volume.

Fragility can be predicted from cohesive energy.

Abstract

The thermal expansion coefficients, structure factors, and viscosities of twenty-five equilibrium and supercooled metallic liquids have been measured using an electrostatic levitation (ESL) facility. The structure factor was measured at the Advanced Photon Source, Argonne, using the ESL. A clear connection between liquid fragility and structural and volumetric changes at high temperatures is established; the observed changes are larger for the more fragile liquids. It is also demonstrated that the fragility of metallic liquids is determined to a large extent by the cohesive energy and is, therefore, predictable. These results are expected to provide useful guidance in the future design of metallic glasses.