Molecular Dynamics Study of Tension Process of Ni-Based Superalloy

Abstract

To understand the atomistic mechanisms of tension failure of Ni-based superalloy, in this study, the classical molecular dynamics (MD) simulations were used to study the uniaxial tension processes of both the Ni/Ni3Al interface systems and the pure Ni and Ni3Al systems. To examine the effects of interatomic potentials, we adopted embedded atom method (EAM) and reactive force field (ReaxFF) in the MD simulations. The results of EAM simulations showed that the amorphous structures and voids formed near the interface, facilitating further crack propagation within Ni matrix. The EAM potentials also predicted that dislocations were generated and annihilated alternatively, leading to the oscillation of yielding stress during the tension process. The ReaxFF simulations predicted more amorphous formation and larger tensile strength. The atomistic understanding of the defect initiation and propagation during tension process may help to develop the strengthening strategy for controlling the defect evolution under loading.