Toughening 3D-printed Zr-based bulk metallic glass via synergistic defects engineering

3D printing provides a novel approach to fabricate bulk metallic glass components without limitations in size and geometry. However, defects (porosity and partial crystallization) are inevitable, which are detrimental to mechanical properties. The present work shows that by careful control of these defects in a 3D-printed BMG (Zr60.14Cu22.31Fe4.85Al9.7Ag3), a promising combination of high strength (1.8 GPa), and fairly good plasticity (>1%) and fracture toughness (∼45 MPa m1/2) can be achieved via utilizing the strengthening effect (nanocrystalline precipitation) and toughening effect (micropores-induced shear banding). The results indicate that the mechanical properties of 3D-printed BMGs could be tailored by the defect engineering strategy.