Papers by Keyword: Cluster-Plus-Glue-Atom Model

Abstract: [(Mo,Sn)(Ti,Zr)₁₄]Nb₁ serial alloy compositions were designed using a cluster-plus-glue-atom model to receive BCC β-Ti alloys with low Youngs modulus (E) in Ti-based multi-component systems, where the square brackets enclose the coordination polyhedron cluster CN14 of the BCC structure and Nb is the glue atom. These serial alloys were prepared into rods with a diameter of 6 mm by copper-mould suction casting method. XRD and tensile test results indicated that all these alloy series possessed a monolithic BCC structure except [SnTi₁₄]Nb₁ and [(Mo_0.5Sn_0.5)Ti₁₄]Nb₁ due to Sn deteriorating BCC structural stability. A combination of Mo_0.5Sn_0.5 at the cluster center, as well as low-E Nb and Zr in the glue and cluster shell respectively, can reach simultaneously low E and high BCC stability, incarnated in the [(Mo_0.5Sn_0.5)(Ti₁₃Zr)]Nb₁ alloy which has the lowest E of 48 GPa in the suction-cast state.

Abstract: 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-Ni₆Ta₆]Ni₃ 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.