Impact of Nanovoid on Mechanical Behavior and Deformation Evolution of AlCoCrFeNi High-Entropy Alloy

This study investigates the impact of nanovoids on the mechanical characteristics and deformation behavior of AlCoCrFeNi high-entropy alloys (HEAs) under uniaxial tensile loading. Molecular dynamics simulations reveal that the presence and size of nanovoids significantly influence the stress–strain response and microstructural evolution of the material. Larger nanovoids, with a radius of 10 Å, reduce the peak stress by up to 17.68% and Young’s modulus by 13.42%, compared to HEAs without nanovoids. The presence of nanovoids initiates localized atomic deformation, leading to the nucleation of Shockley partial dislocations and the formation of shear bands. These defects propagate and evolve, resulting in twin boundaries, stacking faults, and amorphization of the initial FCC structure under increasing strain. The microstructural transformations and stress–strain fluctuations observed are linked to the generation and annihilation of dislocations, twin boundaries, and stacking faults, emphasizing the critical role of nanovoids in governing the mechanical response and deformation mechanisms of AlCoCrFeNi HEAs.