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

摘要

The glass-forming ability (GFA) of binary metallic glasses was analyzed with data for the liquidus temperature (T_1) 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 △T_1 ≥300K where △T_1 was defined as a decrease in T_1 due to eutectic reaction. The crystalline compounds with structure types of bcc or its derivative type, such as CsCl (B2), CrB (B_f), Al_2Cu (C16) and MoSi_2 (C11_b), tended to be found in AFCR frequently. The total pair-distribution and interference functions revealed a high forming tendency of a noncrystalline Cu_(10)Zr_7 structure created by MD. Simultaneous achievements of the Cu_(10)Zr_7 structure for crystallographic features resulting from the bcc family structure and geometrical features in phase diagram for T_1 affect the formation of Cu_(61.8)Zr_(38.2) BMG.