Designed heterogeneities improve the fracture reliability of a Zr-based bulk metallic glass

Abstract

Bulk metallic glasses (BMGs) have been reported to have large variability in mode I fracture toughness. In this study, alternating soft and hard regions were created in a Zr₅₂.₅Ti₅Cu₁₈Ni₁₄.₅Al₁₀ (at%) BMG via mechanical imprinting at room temperature. While only 50% of as-cast samples demonstrated plastic deformation during mode I fracture tests, 100% of imprinted samples demonstrated measurable plasticity and the scatter in measured mode I fracture toughness was significantly reduced. Mechanical treatments show promise for improving the fracture reliability of BMGs.Keywords: Fracture toughness, Fracture morphology, Shear bands, Ductility, Bulk metallic glasse