Plastic deformation mechanism of γ phase Fe-Cr alloy revealed by molecular dynamics simulations

Due to their outstanding mechanical properties, anti-corrosion properties, and anti-irradiation swelling properties, Fe-Cr alloys have been fully improved and developed for nuclear energy applications as structural materials. To ensure the performance stability of gamma-phase Fe-Cr alloys, the present study adopted molecular dynamics (MD) simulations to explore the plastic deformation mechanism of these alloys. The slip model was constructed, and the generalised stacking fault energy (GSFE) and Peierls-Nabarro (P-N) equations were solved, revealing that {110}<111> is the preferentially activated slip system. The twinning model was constructed and the generalised plane fault energy was solved, demonstrating that twinning is preferred over slipping in the {112}<111> system. The above findings are also verified through MD simulations in which Fe-Cr specimens are stretched along the [100] direction. In addition, in the 15 at.%-25 at.% Cr range, an increase in the Cr content has a negative effect on slip but a positive effect on twin formation.