Plastic Deformation Mechanism of γ Phase Fe-Cr Alloy Revealed by Molecular Dynamics Simulations

Abstract Due to its outstanding mechanical properties, anti-corrosion properties, and anti-irradiation swelling properties, Fe-Cr alloy has been fully improved and developed in nuclear energy applications as a structural material. In order to ensure the performance stability of γ phase Fe-Cr alloy, the present study adopts molecular dynamics simulation to explore its plastic deformation mechanism. By constructing the slip model and solving the generalized stacking fault energy and Peierls-Nabarro equation, it is found that {110}<111> is the preferentially activated slip system. By constructing the twin model and solving the generalized plane fault energy, it is found that twin is preferred over slip in {112}<111> system. The above findings are also verified through stretching Fe-Cr specimen along the [100] direction by molecular dynamics simulations. In addition, in the composition range of 15at.%-25at.% Cr, the increase of Cr content has the negative effect on slip but the positive one on twin formation.