Molecular dynamics simulation of the γ’ phase deformation behaviour in nickel-based superalloys

Abstract

The effects of γ′ phase volume fraction, morphology and size on tensile deformation behaviour of Ni-based superalloys at 300 K were studied using molecular dynamics simulation. The differences caused by different parameters were discussed in terms of atomic structure evolution, dislocation motion and stress–strain curve. The results showed that when the volume fraction of the γ′ phase was between 50% and 70%, the tensile strength and elongation increased with the volume fraction, but the variation trend was opposite when it was less than 50%. The cubic γ′ phase produced larger resistance to plastic deformation. Models with different-sized γ′ phases contributed to different fracture modes. Dislocation pile-up was avoided owing to the progressive movement of partial dislocations.