Approaching the intrinsic strength of metallic glasses at ultra-high strain rates

Metallic glasses have attracted a significant amount of attention for their outstanding mechanical properties, such as ultrahigh elastic limit and toughness. Yet, so far, the measured strength of metallic glasses is notably below their theoretical limit. In this Letter, we carry out spallation tests on Cu-Zr metallic glasses that employ a nanosecond laser pulse to achieve ultra-high strain rates up to 3*10^7 s^-1. As high as 9.0 GPa, the measured spall strength approaches the theoretical limit under the uniaxial strain condition. Furthermore, the strain-rate-dependent cavitation dynamics is revealed by the post-mortem characterizations and confirmed by atomistic simulations.