Design of Zr–Al–Ni–Cu bulk metallic glasses with network structures

•Some Zr-based BMGs characterize in the network structures.•The cell size depends on the compositions of the BMGs.•The cell size influences the fracture mode and mechanical property of the BMGs.•The larger is the cell size, the more significant is the serrated flow.

A series of Zr–Al–Ni–Cu bulk metallic glasses (BMGs) with network structures were carefully designed and their heterogeneous microstructures were investigated by carefully etching the cross sections of these BMGs. It is found that the heterogeneous microstructures of these BMGs can be uncovered by etching with mixed solution of HF and HNO3. Some of the studied Zr-based BMGs characterize in micrometer network structure. The cell size of the network structure depends on the composition of the BMG and is related with the fractural mode and mechanical property. The found network structure of the Zr-based BMGs benefits for understanding the unique mechanical properties of the Zr-based BMGs.