Impacts of local chemical ordering on the primary radiation damage in Cr–Fe–Ni multi-principal element alloys

Abstract

Face-centered cubic (FCC) single-phase multi-principal element alloys (MPEAs) have demonstrated promising irradiation resistance. The generation and evolution of irradiation defects are integral aspects to comprehend, as they offer valuable insights into the radiation resistance of materials. In this work, we use molecular dynamics simulations to investigate the primary radiation damage of CrFeNi FCC MPEAs, while focusing on the impact of local chemical ordering (LCO) on the generation and evolution of defects. Our simulation results reveal that the LCO reduces the probability of defect production, consequently mitigating the maximum number of defects. Furthermore, the LCO increases defect migration barriers, thereby impeding the migration of interstitial atoms and leading to an increased number of residual defects subsequent to primary damage. However, the dispersed distribution of defects throughout space facilitates the uniform nucleation of dislocations in subsequent irradiation cascades. Additionally, the increased migration energy acts as a barrier to the movement of defect clusters, impeding their growth and thereby enhancing the radiation resistance of MPEAs. Our findings underscore the potential for enhancing the radiation resistance of MPEAs through the deliberate tailoring of LCOs.