High-strain-rate void growth in high entropy alloys: Suppressed dislocation emission = suppressed void growth

Void growth, as a critical stage in ductile fracture, could play some important role in the ductility of high entropy alloys (HEAs). Under a high-strain-rate tension (strain rate: 0.1 similar to 0.4/ns), our atomistic simulations reveal a severely suppressed growth of void (initial diameter: 4.0 similar to 9.1 nm) in HEAs at a low temperature, compared with that in Ni metal or Ni-based binary alloys. The emission of unclosed glide loops is found critical to void growth. Void growth is suppressed, once dislocation emission is suppressed due to the solute drag effect. Regarding the alloying elements, we find the void suppression relevance as Fe>Co and Cr>Fe>Mn. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.