Molecular dynamics study of interactions between edge dislocation and irradiation-induced defects in Fe–10Ni–20Cr alloy

Abstract

Irradiation-induced defects often hinder the slip of dislocations, which will make the performance of structural materials of nuclear reactor drop sharply, especially for core structural materials. In present work, molecular dynamics method is used to investigate the interactions between edge dislocations and three typical irradiation-induced defects (Void, Frank loop and Stacking fault tetrahedron) with the sizes of 3, 5, and 7 nm at different temperatures in Fe-10Ni-20Cr alloy. The critical resolved shear stress (CRSS) was compared among different defect types after interacting with edge dislocations. The results show that the CRSS decreases with increasing temperature and decreasing defect size for all defect types during the interaction with edge dislocations, except for the case of Frank loops with 3nm at 900 K. By comparison, the CRSS in Frank loops is significantly higher than that of others for the same size, which is due to the occurrence of unfaulting and formation of superjog or stacking-fault complex during the interaction. The atomic evolution of irradiation-induced defects after interacting with dislocations could provide novel insights for the design of new structural materials.