Yuanda Dong

Relationship between the widths of supercooled liquid regions and bond parameters of Mg-based bulk metallic glasses

Abstract The relationship between the widths of supercooled liquid regions (Δ T x ) of Mg-based bulk metallic glasses (BMG) and bond parameters (i.e., electronegativity difference and atomic size parameters) was investigated. From the available experimental data in the literatures, it seems that for Mg-based BMG Δ T x has a close correlation to bond parameters. It increases with the atomic size parameter ( δ ) and electronegativity difference (Δ x ) of Mg-based alloys, which are defined by atomic radius and electronegativity. An equation was deduced for the first time by a linear regression analysis program in order to judge whether Mg-based multicomponent alloys can form metallic glasses.

Thermal and mechanical properties of Zr52.5Al10Ni10Cu15Be12.5 bulk metallic glass

The formation, thermal stability and mechanical properties of Zr52.5Al10Ni10Cu15Be12.5 bulk amorphous alloy were investigated by means of X-ray diffraction, differential scanning calorimetry, differential thermal analysis and tensile strength measurements. Compared with the Zr65Al10Ni10Cu15 amorphous alloy, the substitution of 12.5 at.% Be for part of the Zr results from an off-eutectic alloy composition into a eutectic one, and enhances the reduced glass transition temperature Trg (Tg/Tm) increase from 0.58 to 0.68, ΔTx from 105 to 142 K, and causes a change in fracture strength from 1.33 to 1.75 GPa. These results can be explained on the basis of thermodynamics and topological packing changes by the addition of beryllium.