Deformation mechanisms of CoCrFeMnNi high-entropy alloy under low-cycle-fatigue loading

Plastic deformation during low-cycle fatigue (LCF) in equiatomic face-centered cubic (FCC) CoCrFeMnNi high-entropy alloys (HEAs) is accumulated by dislocation substructure formation, which leads to crack initiation. Whilst these substructures have been reported before, little has done clarify their formation mechanisms and the effects of strain amplitude, cycle number grain orientation. In this study, cyclic behavior microstructural evolution were examined for two different sizes at room temperature. Microstructural investigations transmission electron microscopy showed that, while structures low amplitude (0.3%) mainly consisted planar slip bands, higher amplitudes (0.5% 0.7%), wavy-substructures including veins, walls, labyrinth cells prevailed. Slip mode also changes from initially planar-slip wavy-slip with numbers. Dislocations are found Burgers vectors, suggesting that apart wavy-slip, multiple-slip contributes formation. Moreover, distinct grains dictated more constraints neighboring rather than Additionally, various a single linked constraint grains.