The ternary Ni—Al—Co embedded-atom-method potential for γ/γ′ Ni-based single-crystal superalloys: Construction and application

Abstract

An Ni-Al-Co system embedded-atom-method potential is constructed for the γ(Ni)/γ (Ni 3 Al) superalloy based on experiments and first-principles calculations. The stacking fault energies (SFEs) of the Ni(Co, Al) random solid solutions are calculated as a function of the concentrations of Co and Al. The calculated SFEs decrease with increasing concentrations of Co and Al, which is consistent with the experimental results. The embedding energy term in the present potential has an important influence on the SFEs of the random solid solutions. The cross-slip processes of a screw dislocation in homogenous Ni(Co) solid solutions are simulated using the present potential and the nudged elastic band method. The cross-slip activation energies increase with increasing Co concentration, which implies that the creep resistance of γ(Ni) may be improved by the addition of Co.

Influence of the alloying elements Re, Co and W on the propagation of the Ni/Ni3Al interface crack

“…Then, each model was relaxed by MD simulation with the Ni-Al-X (X = Re, Co, or W) EAM potential [13][14][15]. Finally, a cluster containing 150 atoms located at the crack tip of the Ni/Ni 3 Al interface was selected to perform the DVM calculation.…”

The Large Scale Synthesis of Aligned Plate Nanostructures

“…The results from EBSD and XRD show that the plates generated via thermo-mechanical processing tend to be randomly oriented with respect to the foil surface. One possible reason is the low stacking fault energy in this alloy due to the high amount of Co 26 . However, using the melt spinning method, in which rapid cooling and directional solidification dominate the grain orientation during growth, a strong {100} texture could be achieved 27 , which can then be further heat treated to produce nanoplates with {100} orientation.…”

Effects of Re, W and Co on dislocation nucleation at the crack tip in the γ -phase of Ni-based single-crystal superalloys by atomistic simulation

“…The Ni–Al–X (X = Re, W or Co) EAM potentials fitted the parameters obtained from first-principles calculations or from experimental results, such as lattice constants, cohesive energies, elastic constants of Ni, Al, X (X = Re, W or Co) and their compounds. The Ni–Al–Re, Ni–Al–W, Ni–Al–Co EAM potentials have been applied to predict the physical properties in the respective systems and gave reasonable results [30–32]. In particular, the Ni–Al–Re, Ni–Al–W and Ni–Al–Co EAM potentials have been applied to study the systems containing dislocations or/and cracks [6,23,24,30,33] in the Ni-based superalloys.…”

“…The MD simulation within the framework of embedded atom method (EAM) [28,29] is adopted. For the study of dislocation emission at the crack tip in systems containing Re, W or Co, we use the Ni -Al -Re [30], Ni -Al -W [31], Ni -Al-Co [32] ternary EAM potentials in our research. The Ni -Al -X (X ¼ Re, W or Co) EAM potentials fitted the parameters obtained from first-principles calculations or from experimental results, such as lattice constants, cohesive energies, elastic constants of Ni, Al, X (X ¼ Re, W or Co) and their compounds.…”

“…across the inclined (1 1 1) slip plane in the saddle state when dislocation passes by and the corresponding initial state models are also selected for comparison. The models each containing 171 atoms were relaxed by MD simulation with the Ni-Al-X (X ¼ Re, W or Co) EAM potential[30][31][32] mentioned above. Then they are selected to perform the DVM calculations and the results for the IE are given in figure12.…”