The spall strength of MPG-8 and I-3 graphites under shock loading up to 2 GPa

The spall strength of fine-grained pressed graphite MPG-8 and high-strength isotropic graphite I-3 were measured under shock wave loading with an amplitude not exceeding 2 GPa. Using the VISAR laser Doppler velocimeter, the structure of compression and rarefaction waves in graphite was recorded in experiments. It was found that with an increase in the maximum compression stress, the spall strength of graphite MPG-8 increases significantly, while for graphite I-3 it does not change. The value of the Hugoniot elastic limit of the studied graphites was measured at 0.5 GPa, and a strong dependence of the velocity of the compaction wave on the maximum compression stress was shown.