Primary radiation damage of Fe-10%Cr models under uniaxial, biaxial, and hydrostatic pressure using MD simulation

Abstract

Reduce activation ferritic/martensitic steels are candidate materials for future nuclear reactors due to their superior mechanical properties and reduced swelling under irradiation. In this research, single−crystal models of Fe-10%Cr have been built with [100][010][001] crystal orientations. The models stressed in both compression and tension by applying seven different pressures between −1000 MPa (tension) to +1000 MPa (compression) in uniaxial, biaxial, and hydrostatic cases. Displacement cascades have been initiated by imparting kinetic energy to an atom in the center of the simulation box. The produced point defects have been identified using the Wigner−Seitz cell method. In all cases, increasing the imparted energy increases the number of point defects. For models under uniaxial pressure, three different regions have been identified and each region has its own unique mechanism that controls the defect production process. For models under biaxial and hydrostatic pressure, the number of produced point defects increases with increasing the pressure in both tension and compression regions; in addition, the number of produced point defects with pressures shows an empirical power relationship. The Cr atoms prefer interstitial positions over creating vacancies in all cases.