High strength bioinspired cellular metallic glasses with excellent energy absorption

Bulk metallic glasses (BMGs) have been restricted in structural engineering applications for decades due to their strong yet inherently brittle nature, which can lead to catastrophic failure owing to strain-softening originating from shear localization. Using architectural design to alter the localized deformation is key to solving this dilemma. In this study, four types of bioinspired triply periodic minimal surface (TPMS) structures were constructed using Zr-based MG powders via the micro Laser Powder Bed Fusion (μLPBF) technique. Two types of TPMS structures were found to reach remarkable energy absorption capabilities above 30 kJ/kg and high specific strength above 0.08 MPa·kg⁻¹·m³. By investigating the fracture morphology and using digital volume correlation (DVC) analysis, we identified a hybrid ductilization mechanism at both the macro and micro levels in the deformation process of MG TPMS structures. The MG lattices dissipate energy through crack bands and shear bands, leveraging their plasticity and controllable crack propagation to maximize the energy absorption capacity of BMGs. Our work offers a new approach in overcoming the strength-plasticity trade-off, enabling the development of high-strength architected metallic glasses with excellent energy absorption, which holds great promise for energy-absorbing applications. © 2024 Acta Materialia Inc.