Plasticity of bulk metallic glasses improved by controlling the solidification condition

Different bulk metallic glasses (BMGs) were prepared in ductile Cu_47.5Zr_47.5Al₅, Zr₆₂Cu_15.4Ni_12.6Al₁₀, and brittle Zr₅₅Ni₅Al₁₀Cu₃₀ alloys by controlling solidification conditions. The achieved microstructures were characterized by x-ray diffraction, differential scanning calorimetry, transmission electron microscopy, and synchrotron- based high-energy x-ray diffraction. Monolithic BMGs obtained by high-temperature injection casting are brittle, while BMGs bearing some nanocrystals with the size of 3 to 7 nm and 2 to 4 nm, obtained by low-temperature injection casting and in situ suction casting, respectively, exhibit good plasticity. It indicates that the microstructures of BMGs are closely affected by the solidification conditions. Controlling the solidification conditions could improve the plasticity of BMGs.