Enhancement of mechanical properties in 3D-printed Zr-based bulk metallic glass composites via multiscale heterogeneous structures

The inescapable precipitation of brittle intermetallics in 3D-printed bulk metallic glasses (BMGs) significantly deteriorates their plasticity. To solve this problem, a novel scanning strategy (alternating high and low laser energy density between layers) was developed to regulate B2-CuZr distribution in the 3D-printed Zr47.5Cu45.5Al5Co2 alloy, producing a multiscale heterostructure. The coupling effect of B2-CuZr phase transformation and multiscale heterostructure promotes the formation of massive shear bands while suppressing their unstable propagation, significantly enhancing the strength-plasticity synergy with ∼1.2 GPa yield strength, ∼1.9 GPa fracture strength and ∼7% plastic strain. This work offers a novel avenue to fabricate high-performance BMG composites.