Binary Ni-Ta bulk metallic glasses designed by using a cluster-plus-glue-atom model

摘要

With the aid of the atomic-cluster-plus-glue-atom model (ACPGA model) proposed by Dong et al [1] for bulk metallic glasses (BMGs), the formation and characteristic of Ni-Ta binary BMGs were investigated in this work. Binary glass-forming compositions containing 56.3-62.5 at.%-Ni were obtained by a composition formula [M-Ni_6Ta_6]Ni_3 based on the ACPGA model. It was found that Ni-Ta BMGs with a diameter of 2 mm was obtained over a composition range of 59 ~ 62 at.%-Ni by copper mold casting method, which are in good agreement with our model prediction. Newly-developed Ni-Ta BMGs are a kind of extreme materials, which exhibit superior thermal stability (T_g = 993K) and a ultrahigh fracture strength of about 3.5 GPa.