Atomistic simulations of solid solution strengthening in Ni-based superalloy

The interaction between an edge dislocation and the solid solution elements (Co, Ru and Re) of different concentration in Ni is investigated by means of molecular dynamics simulation. It is figured out that Ru atoms hinder dislocation movement more effectively than Co atoms under the same concentration. The solid solution strengthening of Re atoms being introduced to Ni crystal is obviously stronger than that of Co and Ru atoms addition. With first-principles density functional theory approach, it is found that one of the leading factors of solid solution strengthening can be attributed to the interaction between host atoms and solid solution elements located in the slip plane, which leads to the stacking-fault energy increasing.