A CuZr-based bulk metallic glass composite with excellent mechanical properties by optimizing microstructure

The dependence of microstructure and mechanical properties on alloy composition of a series of Cu48Zr48-xAl4Nbx (x = 0, 0.3, 0.8, 1.2, 1.5, 2.0 at.%) bulk metallic glass composites (BMGCs) was studied in detail. It was found that the doping element Nb exerts a crucial role on the mechanical properties of the studied BMGCs. By adjusting Nb content, a BMGC possessing an excellent combination of high strength (similar to 1.3 GPa) and significant tensile plasticity (similar to 8%) was obtained. Such superior mechanical performance can be attributed to the formation of multiple shear bands and the deformation-induced martensitic transformation from a cubic primitive B2 phase to a monoclinic B19' phase.