The effect of microalloying on mechanical properties in CuZrAl bulk metallic glass

The effect of the minor addition of elements Ta and Fe on the mechanical properties of the CuZrAl BMG was investigated by compression tests. It was found that the addition improves significantly the plasticity at room temperature. The compressive plastic strain enhanced from 0.59% for Cu46Zr47Al7 BMG to 2.62% and 4.81% for Cu46Zr45Al7Ta2 and Cu44Zr47Al7Fe2 BMG, respectively. The microstructure of Cu44Zr47Al7Fe2 BMG was further investigated by TEM, which reveals the occurrence of phase separation with the formation of a Cu-rich phase and a Fe-rich phase due to the minor addition of Fe. The formation of inhomogeneous structure in amorphous phase, which results in the activation of multi shear bands, can account for the improvement of the plasticity of the base BMG. The present results provide a promising approach to enhance the plasticity of BMGs through compositional and structural design by microalloying.