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 results are tempered by the fact that the slowest cooling rates achieved in our simulations correspond to similar to 10(11) K/s, which is several orders of magnitude higher than R-c for typical BMGs. Despite this, our studies represent a first step in the development of computational methods for quantitatively predicting glass-formability. (C) 2013 AIP Publishing LLC.
