Construction and application of multi-element EAM potential (Ni–Al–Re) inγ/γ′ Ni-based single crystal superalloys

Abstract

Based on experiments and first-principles calculations, a Ni–Al–Re system embedded atom method (EAM) potential is constructed for the γ(Ni)/γ′(Ni3Al) superalloy. The contribution of the inner elastic constants is considered in the fitting of Re with a hexagonal close-packed structure. Using this potential, point defects, planar defects and lattice misfit of γ(Ni) and γ′(Ni3Al) are investigated. The interaction between Re and the misfit dislocation of the γ(Ni)/γ′(Ni3Al) system is also calculated. We conclude that the embedding energy has an important effect on the properties of the alloys, such as the planar fault energies of Ni3Al, by considering the relationship between the charge transfer calculated from first-principles, the elastic constants of Ni3Al and the host electron density of the EAM potential. The multi-element potential predicts that Re does not form clusters in γ(Ni), which is consistent with recent experiments and first-principles calculations.

Modelling defects in Ni–Al with EAM and DFT calculations

“…However, this ternary potential is not yet fully reliable as it has been reported to overestimate the lattice parameters and to predict spurious Rhenium clustering in the γ phase not observed by extended x-ray absorption fine structure and atom probe tomography [7,8] and later ruled out using DFT calculations [10]. Another ternary potential was constructed by Du et al [39] based on a previous model for generic fcc structures [40]. In the present work we have tested this potential against DFT forces and found large deviations when modelling substitutional rhenium impurities in γ.…”

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

“…In the present work, the effect of Re on the dislocation nucleation from a crack tip in Ni, including the activation energy and frequency of dislocation nucleation, is investigated using the climbing image nudged elastic band (CI-NEB) method [15][16][17] with a Ni-AlRe embedded-atom-method (EAM) potential [18]. This potential has been applied to predict the effect of Re on the dislocation and crack in Ni or Ni/Ni 3 Al interface [18][19][20] …”

“…This potential has been applied to predict the effect of Re on the dislocation and crack in Ni or Ni/Ni 3 Al interface [18][19][20] …”

Effect of Re on lattice trapping in γ′-Ni3Al cracks by atomistic simulation

“…In the present study, the effect of Re on the lattice trapping at the (0 1 0)[0 0 1], (1 0 1)[0 1 0] and (0 1 0)[1 0 1] crack orientations in c 0 -Ni 3 Al was investigated at 0 K, using the MD simulation with a Ni-Al-Re EAM potential [29] and the XMD program [30]. The contents to be discussed included the influences of a single Re atom at the crack tip and different Re concentrations (3 at.% or 6 at.% Re atoms randomly distributed in the c 0 -Ni 3 Al phase) on the lattice trapping of a crack.…”

“…A time step of 5 Â 10 À15 s was used. The Ni-Al-Re embeddedatom-method (EAM) potential [29], which can successfully describe the effect of Re in the Ni-Al crack system [10,32], has been applied.…”