Evolution of B19' phase during annealing and its influence on the mechanical properties of Zr45Cu45Al10 metallic glass composites

Metallic glass composites containing shape memory crystals demonstrate strain hardening owing to the deformation-induced martensitic transformation, which encompasses the B2 B19 & PRIME;/B33 (martensite) trans-formation in Zr-based metallic glasses. However, the impact of the B19' martensitic phase on strain hardening remains ambiguous. In this study, we conduct a rapid annealing treatment of Zr45Cu45Al10 bulk metallic glass at 748 K to form the B19' phase and employ small-angle neutron scattering to explore its evolution. The B19' phase forms in the first 10 min of annealing treatment and begins to grow after 30 min. The presence of the B19' phase significantly increases the strain rate sensitivity and irreversible plastic deformation. These findings not only deepen our understanding of the role of the B19' phase in metallic glass composites but also offer a methodology to enhance their mechanical properties through modulation of the B19' phase.