Hierarchical amorphous structures in a Zr50Cu42Al8 bulk metallic glass

The mechanism for the room-temperature plasticity of bulk metallic glasses (BMGs), in most cases adopting the microscopic point of view, has been extensively studied. However, less attention has been paid to the macro-structural heterogeneity of BMGs. In this work, a hierarchical amorphous structure, from the full amorphous surface to the phase-separated central region, has been observed in a Zr50Cu42Al8 glassy rod, displaying excellent room-temperature plasticity under compression. The formation mechanism for the hierarchical structure and its effect on the deformation behavior of the glassy rod have also been investigated.