Effects of Re, Ta, andWin [110] (001) dislocation core of γ/γ′ interface to Ni-based superalloys: First-principles study*

Abstract

The strengthening effects of alloying elements Re, Ta, and W in the [110] (001) dislocation core of the γ / γ′ interface are studied by first-principles calculations. From the level of energy the substitution formation energies and the migration energies of alloying elements are computed and from the level of electron the differential charge density (DCD) and the partial density of states (PDOSs) are computed. Alloying elements above are found to tend to substitute for Al sites γ′ phase by analyzing the substitution formation energy. The calculation results for the migration energies of alloying elements indicate that the stability of the [110] (001) dislocation core is enhanced by adding Ta, W, and Re and the strengthening effect of Re is the strongest. Our results agree with the relevant experiments. The electronic structure analysis indicates that the electronic interaction between Re-nearest neighbor (NN) Ni is the strongest. The reason why the doped atoms have different strengthening effects in the [110] (001) dislocation core is explained at the level of electron.

Nonlinear optical properties in n-type quadruple δ-doped GaAs quantum wells

“…For instance, the density functional theory (DFT) can describe accurately the physical properties in multiple materials. [1][2][3][4][5] However, in this method, the calculation time efficiency in the processes is mainly determined by the diagonalization routines. [6] Besides, another approach, the Thomas-Fermi (TF) theory [7,8] allows the determination of the electronic structure with a very simple way in comparison to the DFT.…”

Study on the dislocation mechanism of Ni47Co53 alloy during rapid solidification

“…Recently, the first principles method has been used to study the strengthening effect of alloying elements Re, Ta, and W in the γ/γ ′ interface [110] (001) dislocation core. [18] By analyzing the substitution formation energy and alloy-element migration energy, it was found that the stability of [110] (001) dislocation core is enhanced by adding Ta, W, and Re. Rapid solidification was widely used as an important material preparation method to enhance their properties.…”