The effect of short-range order on mechanical properties of high entropy alloy Al0.3CoCrFeNi

Recent studies show that the atoms in high entropy alloys (HEAs) are not randomly distributed but have a certain short-range order (SRO). However, the study of the effect of SRO on Al0.3CoCrFeNi properties is insufficient. In this paper, the effect of SRO on the mechanical properties of Al0.3CoCrFeNi was investi-gated by molecular dynamics (MD). Melting/quenching and hybrid Monte Carlo (MC)/MD optimization were used to order the random distribution model. The effects of SRO on tensile and shear properties, stacking fault energy (SFE) and dislocation slip were comparatively analyzed and systematically dis-cussed. The results show that the SRO inhibited the propagation of SFs and enhanced dislocation storage capacity. The ordering of the single crystals promoted the formation of deformation twins. The ordering of the polycrystals leads to martensite, BCC phase transformation, and activation of the sub-slip planes. SRO resulted in more severe SFE fluctuation, a more tortuous dislocation path, and a stronger pinning effect. The strength and toughness enhancement resulted from plane slip, multi-system slip, deformation twins, and nanoscale precipitates.(c) 2022 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Recent studies show that atoms in high entropy alloys (HEAs) are not randomly distributed, but exhibit a certain short-range order (SRO). However, the effect of SRO on the properties of Al0.3CoCrFeNi is not well-studied. In this paper, molecular dynamics (MD) simulations were conducted to investigate the effect of SRO on the mechanical properties of Al0.3CoCrFeNi. The results suggest that SRO inhibits the propagation of stacking faults (SFs), enhances dislocation storage capacity, and promotes the formation of deformation twins.