Evaluation of glass-forming ability of binary metallic glasses with liquidus temperature, crystallographic data from binary phase diagrams and molecular dynamics simulations

The glass-forming ability (GFA) of binary metallic glasses was analyzed with data for the liquidus temperature (Tl) acquired as a function of composition from binary phase diagrams, assisted by crystallographic data combined with amorphous-forming composition range (AFCR) and molecular dynamics (MD) simulations. A necessary condition for the formation of bulk metallic glasses (BMGs) was determined as ΔTl ≥ 300 K where ΔTl was defined as a decrease in Tl due to eutectic reaction. The crystalline compounds with structure types of bcc or its derivative type, such as CsCl (B2), CrB (Bf), Al2Cu (C16) and MoSi2 (C11b), tended to be found in AFCR frequently. The total pair-distribution and interference functions revealed a high forming tendency of a noncrystalline Cu10Zr7 structure created by MD. Simultaneous achievements of the Cu10Zr7 structure for crystallographic features resulting from the bcc family structure and geometrical features in phase diagram for Tl affect the formation of Cu61.8Zr38.2 BMG.