Effect of ion flux on one-dimensional migration of dislocation loops in Fe9Cr1.5W0.4Si F/M steel during in-situ Fe plus irradiation

The study of one-dimensional (1D) migration of dislocation loops is essential for understanding the evo-lution of material microstructure in the irradiation environment. The 1D migration of dislocation loops under thermal activation and electron irradiation has been widely studied, but the effect of ion flux on the 1D migration of dislocation loops has not been concerned. In this study, the 1D migration and evolu-tion of dislocation loops in the Fe9Cr1.5W0.4Si ferrite/martensite steel during 400 keV Fe+ irradiation was investigated by in-situ transmission electron microscopy at room temperature. Compared with 1/2 < 111> dislocation loops, (100) dislocation loops had weak migration ability and low migration frequency. The effect of ion flux on the 1D migration of dislocation loops were explored, which showed that increasing the ion flux was not only beneficial to the migration of large dislocation loops, but also increased the mi-gration frequency. In addition, the higher the ion flux, the higher the density of mobile dislocation loops per unit irradiation dose. The knowledge gained here provides an important reference for understanding and predicting the degradation process of irradiated materials.(c) 2023 Elsevier B.V. All rights reserved.