Extraordinary plasticity of an amorphous alloy based on atomistic-scale phase separation

A bulk amorphous alloy, Zr54Cu36Al4Be6, was synthesized. This alloy shows a large plastic strain of ∼22.1% along with a work hardening of 485 MPa, which have hardly been observed in monolithic bulk amorphous alloys. Microstructures of this alloy were observed to investigate the origin of the extraordinary plasticity of the alloy. The alloy exhibited a unique microstructure characterized by an atomistic-scale phase separation, which probably stems from the large difference in mixing enthalpy between the binary pairs of Zr–Be and Cu–Be. This paper discusses the possible mechanism underlying the extraordinary plasticity of the alloy by considering the atomic packing density and atomistic-scale compositional separation induced by Be.