Molecular dynamics simulating collision cascade in irradiated Ni–Fe alloy with uniaxial strain

Single-phase concentrated solid-solution alloys have garnered widespread attention due to their remarkable irradiation resistance properties. In this study, the molecular dynamics method was employed to investigate the collision cascade process in Ni–Fe alloys. The generation and evolution of point defects under uniaxial strain were systematically analyzed for alloys with varying Fe concentrations. It was observed that the peak number of point defects increased under tensile strain but decreased under compressive strain as the uniaxial strain magnitude rose. However, the uniaxial strain exhibited only a minor influence on the surviving number of defects. The calculated formation energies revealed that Fe vacancies possessed higher formation energies compared to Ni vacancies. Consequently, an increase in Fe concentration led to greater participation of Fe atoms in collision cascades, resulting in fewer point defects during the thermal peak stage. Owing to the elevated defect formation energies of Fe relative to Ni, the proportions of Fe vacancies and interstitials in the total point defects were consistently lower than the Fe atomic concentration. These findings indicate that higher Fe concentrations impede the formation of point defects.