This study uses molecular dynamics (MD) simulations to investigate the defect healing mechanisms in Fe-Cr-Ni single crystal alloys under multiaxial cyclic loading. Focusing on enhancing the mechanical strength of these alloys for aerospace, automotive, nuclear, and marine applications, the research examines atomic-scale healing of preexisting defects. Triaxial cyclic loading simulations at 300K reveal that defect healing primarily occurs through dislocation cross-slip, climb, atomic diffusion, and crystalline structure recovery. The closure of voids is facilitated by dislocation tangle formation, stacking fault evolution, and extrinsic-to-intrinsic stacking fault transitions. Complete void healing is achieved by the 15 th cycle in triaxial loading, 19 th in biaxial, and 27 th in uniaxial loading. Phase transformation analysis confirms the dominance of the FCC phase, with localized HCP formations aiding structural recovery. These findings provide critical insights into atomic-scale defect healing mechanism, offering strategies to enhance fatigue resistance, structural integrity, and long-term performance of Fe-Cr-Ni alloys under cyclic loading.

This study used molecular dynamics (MD) simulations to investigate the defect healing mechanisms in Fe-Cr-Ni single crystal alloys under multiaxial cyclic loading. This study, which focuses on improving the mechanical strength of these alloys for applications in the aerospace, automotive, nuclear, and marine sectors, looks at the healing of pre-existing defects at the atomic level. Triaxial cyclic loading simulations at 300 K show that defect healing is predominantly achieved by dislocation processes like as cross-slip and climb, which are combined with atomic diffusion and crystalline structure recovery. The growth of dislocation tangles and stacking faults, as well as the transition from extrinsic to intrinsic stacking faults, is crucial for void closure and material strength. The complete healing of pre-existing voids is achieved by the 15 th cycle, as indicated by reductions in dislocation density, void size, and the stabilization of potential energy. In comparison, complete healing is observed by the 19 th and 27 th cycles under biaxial and uniaxial cyclic loading, respectively. Furthermore, phase transformation analysis reveals that the FCC phase remains predominant, while localized increases in the HCP phase contribute to structural recovery. This study provides solutions to enhance the fatigue resistance, structural integrity, and long-term performance of Fe-Cr-Ni alloys under cyclic loading situations by revealing important light on the atomic-scale defect healing mechanisms.