Numerical and experimental studies on the shear band intervention in zirconium based bulk metallic glass composites Zr_(53)Cu_(22)Ni_9Al_8Ta_8

摘要

The Zr_(53)Cu_(3o-x)Ni_9Al_8Ta_x (x = 2, 4, 6, 8) bulk metallic glass composites (BMGCs) rods had been demonstrated their superior mechanical performance in our recent study due to the presence of micro-(10—30 μm) and nano-sized (10—80 nm) Ta-rich particles produced by the in-situ precipitation. These uniformly distributed particles in the amorphous matrix acted as scattered obstacles to effectively impede and deflect the propagation of shear bands and thus avoid catastrophic failures of materials. However, how the shear bands deform and evolve under different levels of loading and the quantitative description of such phenomenon is yet an amenable question for engineering designs. In this study, the selected Zr_(53)Cu_(22)Ni_9Al_8Ta_8 BMGCs rods with size of 2 mm in diameter was plastically deformed by compression at different strain level, namely, 3%, 8%, 15% and 25%, to investigate the interactions between the Ta-rich macro particles and shear banding. Corresponding numerical analyses on the compression test and on a small element from SEM images of deformed rods were also performed to provide a quantitative measure on the experimental observations.