Unifying interatomic potential, g(r), elasticity, viscosity, and fragility of metallic glasses: analytical model, simulations, and experiments

Abstract

An analytical framework is proposed to describe the elasticity, viscosity and fragility of metallic glasses in relation to their atomic-level structure and the effective interatomic interaction. The bottom-up approach starts with forming an effective Ashcroft-Born-Mayer interatomic potential based on Boltzmann inversion of the radial distribution function g(r) and on fitting the short-range part of $g(r)$ by means of a simple power-law approximation. The power exponent $\lambda$ represents a global repulsion steepness parameter. A scaling relation between atomic connectivity and packing fraction $Z\sim {\varphi }^{1+\lambda }$ is derived. This relation is then implemented in a lattice-dynamical model for the high-frequency shear modulus where the attractive anharmonic part of the effective interaction is taken into account through the thermal expansion coefficient which maps the $\varphi$-dependence into a $T$-dependence. The shear modulus as a function of temperature calculated in this way is then used within the cooperative shear model of the glass transition to yield the viscosity of the supercooled melt as a double-exponential function of $T$ across the entire Angell plot. The model, which has only one adjustable parameter (the characteristic atomic volume for high-frequency cage deformation) is tested against new experimental data of ZrCu alloys and provides an excellent one-parameter description of the viscosity down to the glass transition temperature.

arXiv commentSpecial Issue on Structure in Glassy and Jammed Systems

References in corpus (11)

• Theoretical perspective on the glass transition and amorphous materials
• On the Rigidity of Amorphous Solids
• Approximate analytical description of the nonaffine response of amorphous solids
• Local inversion-symmetry breaking controls the boson peak in glasses and crystals
• Why are glass-forming liquids non-Arrhenius?
• Interatomic repulsion softness directly controls the fragility of supercooled metallic melts
• Disorder-assisted melting and the glass transition in amorphous solids
• Correlation between Fragility and the Arrhenius Crossover Phenomenon in Metallic, Molecular, and Network Liquids
• Microscopic origin of nonlinear non-affine deformation and stress overshoot in bulk metallic glasses
• Network disorder and nonaffine deformations in marginal solids
• Importance of non-affine viscoelastic response in disordered fibre networks

Cited by in corpus (5)

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• Disentangling interatomic repulsion and anharmonicity in the viscosity and fragility of glasses
• Atomic-scale expressions for viscosity and fragile-strong behavior in metal alloys based on the Zwanzig-Mountain formula
• Fragile-to-strong glass transition in two-dimensional vortex liquids
• Phenomenological model of supercooled liquid as a possible resolution of the Kauzmann paradox