Abstract:The molecular dynamics (MD) simulation and the modified analytical embedded-atom method (MAEAM) were used to study the influence of a He atom on the movement of the edge dislocation in Ni. First, the calculated Burgers vector distribution shows that the equilibrium dissociation distance (D_ed) and the stacking fault energy (E_sf) between two partial edge dislocations are about 25.95 ？ and 108 mJ/m², respectively. Then, the obtained formation energies (E_f) of a He atom at some different sites demonstrate that the He atom is attracted and repelled in the tension and compression regions, respectively. And the He-dislocation interaction reveals that an interstitial He atom plays a more significant role in the dislocation movement than a substitutional He atom. Finally, it is found that the movement of an interstitial He atom is apparent as the first partial dislocation bypasses and the edge dislocation offers fast-diffusion path for the migration of a He atom.

Key words: movement; edge dislocation; He; atomic simulation; Ni