Atomistic insights into the structural, thermal, and mechanical evolution of $Zr_{47.5}Cu_{47.5}Ag_{5}$ bulk metallic glass

Abstract

Bulk metallic glasses (BMGs) are distinguished by amorphous atomic structures that confer superior mechanical performance; however, the evolution of these properties in ternary bulk configurations remains insufficiently explored. In this study, we employed large-scale molecular dynamics simulations to investigate the structural, thermal, and mechanical properties of $Zr_{47.5}Cu_{47.5}Ag_{5}$ BMGs. Our thermodynamic and topological analyses, utilizing potential energy regression and the Modified Wendt-Abraham parameter, identified a glass transition temperature ($T_g$) of approximately $692\text{ K}$. Structural characterization via Voronoi tessellation and partial radial distribution functions reveals that the amorphous matrix is stabilized by icosahedral clusters, with Ag atoms inducing significant chemical heterogeneity through localized nano-clustering. Thermal transport properties, computed via the Green-Kubo formalism, demonstrate a monotonic decrease in conductivity with temperature, consistent with structural scattering saturation in disordered lattices. Mechanical tensile testing reveals that the material exhibits robust rate- and temperature-dependent behavior, with yield strengths reaching $\approx 2.3\text{ GPa}$ at room temperature. We show that macroscopic strain-softening is intrinsically linked to the thermally induced collapse of rigid icosahedral motifs, which facilitates shear band percolation. These findings provide a structural rationale for the beneficial role of Ag dopants in enhancing the resilience of multicomponent metallic glasses.