Shock-induced spallation in a nanocrystalline high-entropy alloy: An atomistic study

High-entropy alloys are attracting an increasing interest due to their promising mechanical properties. However, their high-pressure properties are not fully understood. We study shock-induced spallation in a nanocrystalline high-entropy alloy using various grain sizes. Our results show that the spall strengths for the nanocrystals are significantly reduced in comparison to single crystals. In contrast to previous results on single crystals, we observe a large number of stacking faults, twins, and dislocations during the shock, which persist even during the release of the shock wave. This behavior is in good agreement with recent experiments of shock loading via high power lasers where pronounced nanotwinning has been observed in the recovered samples.

Automated summary

High-entropy alloys are promising materials with excellent mechanical properties. The spall strengths of nanocrystalline high-entropy alloys are significantly reduced compared to single crystals, and the presence of stacking faults, twins, and dislocations during shock loading is consistent with recent experimental observations.