Computational studies of the glass-forming ability of model bulk metallic glasses

Abstract

Bulk metallic glasses (BMGs) are produced by rapidly thermally quenching supercooled liquid metal alloys below the glass transition temperature at rates much faster than the critical cooling rate R_c below which crystallization occurs. The glass-forming ability of BMGs increases with decreasing R_c, and thus good glass-formers possess small values of R_c. We perform molecular dynamics simulations of binary Lennard-Jones (LJ) mixtures to quantify how key parameters, such as the stoichiometry, particle size difference, attraction strength, and heat of mixing, influence the glass-formability of model BMGs. For binary LJ mixtures, we find that the best glass-forming mixtures possess atomic size ratios (small to large) less than 0.92 and stoichiometries near 50:50 by number. In addition, weaker attractive interactions between the smaller atoms facilitate glass formation, whereas negative heats of mixing (in the experimentally relevant regime) do not change R_c significantly. These studies represent a first step in the development of computational methods for quantitatively predicting glass-formability.

8 pages, 9 figures

References in corpus (3)

• Structure identification methods for atomistic simulations of crystalline materials
• Irreversible reorganization in a supercooled liquid originates from localised soft modes
• Phase diagram and structural diversity of the densest binary sphere packings

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• Asymmetric crystallization during cooling and heating in model glass-forming systems
• Hopper flows of deformable particles
• Glass formation in binary alloys with different atomic symmetries
• The glass-forming ability of binary Lennard-Jones systems
• Incorporating a soft ordered phase into an amorphous configuration enhances its uniform plastic deformation under shear