Measurement of the strengths of Be and Pb4Sb by quasi-isentropic compress and release at near 100 GPa

Ramp-compression experiments have been performed on the “Z” pulsed-power facility to investigate the strengths of Be and lead–antimony alloy. Yield strength and shear stress near peak pressure were obtained from measurements of the sound speed on release and using the Asay self-consistent method. Two S-65 grade Be samples, from batches that showed a significant difference in yield strength at ambient conditions, were found to have near identical yield strengths, which were also in agreement with similar earlier measurements on S-200 grade Be. Yield strength of the Pb4Sb alloy at ∼120 GPa was 1.35 GPa, while a National Ignition Facility experiment by Krygier et al. [Phys. Rev. Lett. 123, 205701 (2020)] found 3.8 GPa at ∼400 GPa pressure. Our result is intermediate between the ambient value and the one by Krygier et al., but the significantly increased strength is probably not associated with the transition to the high-pressure bcc phase of lead.