Testing of high-strength Zr-based bulk metallic glass with the split Hopkinson pressure bar

The split Hopkinson pressure bar (SHPB) was used to determine the dynamic compressive strength of the high-strength Zr₃₈Ti₁₇Cu_10.5 Co₁₂Be_22.5 bulk metallic glass at strain rate on the order of 10² s^-1. It is shown that at high strain rates beyond about 1000 s^-1, uniform deformation within the metallic glass specimen could not be achieved and dispersion in the transmitted pulse can lead to discrepancies in measuring the dynamic failure strength of the present Zr-based bulk metallic glass. Based on these reasons, a copper insert was placed between the strike bar and the input bar to obtain reliable and consistent experimental data for testing of the Zr₃₈Ti₁₇Cu_10.5 Co₁₂Be_22.5 bulk metallic glass using the SHPB. Negative strain rate sensitivity was found in the present Zr-based bulk metallic glass.