Computational investigation of superalloy persistent slip bands formation

Persistent slip bands (PSB) is the important and typical microstructure generated during fatigue crack initiation. Intensive works have been done to investigate the mechanisms of the formation of persistent slip bands in the past decade. In this paper, a molecular dynamics (MD) simulation associated with embedded atom model (EAM) is applied on the PSBs formation in nickel-base superalloys with different microstructure and temperature under tensile-tensile loadings. Simulation results show that PSBs formed within the γ phase by massive dislocations pile-up and propagation which can penetrate the grain. Also, the temperature will affect the material fatigue performance and blur PSBs appearance. The simulation results are in strong agreement with the experimental test results published before.