Effect of Re on dislocation nucleation from crack tip in Ni by atomistic simulation

The effect of Re on the dislocation nucleation from a crack tip in Ni is investigated using the climbing image nudged elastic band method with a Ni-Al-Re embedded-atom-method potential. The activation energy and frequency of dislocation nucleation are calculated. Calculation results show that the activation energy decreases with Re addition. The decrease of activation energy may be related to the expansion of local structure around the Re atom when dislocation goes through the Re atom. The calculations also show that the frequency of dislocation nucleation can be improved with the Re addition at 300 or 1500 K, which means that the ductility of crack in Ni may be enhanced by Re. (C) 2014 Published by Elsevier B.V.