The enhancement of damage tolerance of 3D-printed high strength architected metallic glasses by unit cell shape design

In this work, we developed a strategy that can simultaneously enhance the strength and energy absorption of 3D-printed architectural Zr-based bulk metallic glass (BMG) through unit cell shape design. Strut-based body-centered tetragonal (BCT) with different scaling degrees were incorporated into the conventional metallic glass architectures to avoid the fast propagation of main crack bands and induce multiple micro fracturing of the metallic glass (MG) lattices. Thus, the failure characteristics of 3D-printed architectural BMG underwent a remarkable transformation from a catastrophic fracture to a sequential localized fracture, which effectively overcomes catastrophic failure. It is evidenced by the emergence of a smooth plateau in the stress-strain curves, signifying enhanced damage tolerance. Consequently, the energy absorption capacity increased by 2.2 times, with the compressive strength increased by various degrees compared to the body centered cubic (BCC) structure, indicating the viability of this shape design strategy. Therefore, this work provides a novel route for material-structure-combined design to simultaneously improve the strength and energy absorption of BMG. This breakthrough also enables architected MGs to overcome their inherent extreme brittleness, unlocking their vast potential for crafting impact-resistant and energy-absorbing intricate structural components through lightweight design.