Lattice Parameters and Local Lattice Distortions in fcc-Ni Solutions

Abstract

The lattice parameters and the local lattice distortions around solute atoms in fcc-Ni solutions were studied using first-principles calculations. The solute atoms considered include Al, Co, Cr, Hf, Mo, Nb, Re, Ru, Ta, Ti, and W. The calculations were performed using supercells with 1 solute atom and 107 solvent atoms. It is found that the atomic size difference, the electronic interactions, and the magnetic spin relations between the solute and solvent atoms all contribute to the lattice distortions. Based on the results from first-principles calculations, the linear composition coefficients of fcc Ni lattice parameter for different solutes were determined, and the lattice parameters of multicomponent Ni-base superalloys as a function of solute composition were predicted. The results are compared with existing experimental measurements, and good agreements are obtained for both the compositional dependence of lattice parameters and the local lattice distortions.

Lattice properties of supersaturated Ni–Sn solid solutions

“…This suggests that the influence on the lattice distortion from the introduced Sn atoms are mainly constrained to the 1NN atoms and is much weaker for farther atoms. Meanwhile, the distortions do not vary evidently with Sn contents and this is consistent with other Ni or Al based solid solutions[1,2].The measured thermal expansions dL/L 0 for Ni 92 Sn 8 and Ni 96 Sn 4 in two dilatometer cycles, one for the as-cast sample and the other for the annealed sample, are illustrated in…”

“…This value is larger than those for most Ni based solid solutions [2,13] since Sn atom is larger than those solute atoms. Additionally, some referenced data for the solid solutions formed in long-time annealed and quenched Ni-Sn alloys are presented for comparison [8].…”

“…Generally, the lattice constants vary with temperature and compositions, especially for solid solutions. Their changes with temperature will cause the thermal expansion, while their changes with composition will result in both the variation of macroscopic lattice constants and microscopic lattice distortions [1,2]. In experiments, the lattice constants and thermal expansions can be obtained by using X-ray diffraction (XRD) [3,4] or dilatometer method [3,5].…”

Large area strain analysis using scanning transmission electron microscopy across multiple images

“…Atomic-resolution EDS, in Figure 1(b), reveals that Cr predominantly occupies the Al sub-lattice in the c 0 phase, in agreement with recent atom probe tomography experiments 15,16 and first-principles calculations. 17 At the atomic scale, a representative c 0 /c interface is shown in Figure 1(c), where the two regions can be distinguished by the presence of the ordered Al/Cr sub-lattice atom column intensities (dark). In contrast, all atom columns in the c region exhibit similar intensity because a random solid solution is formed on a face-centered cubic lattice.…”

Yttria Dispersion Strengthened Nickel-based Superalloy by Mechanical Alloying

“…As more number of solute particles goes into solution, the lattice parameter of nickel increases. Wang et al 20 reported that for FCCNi solutions the lattice parameter of solvent increased when solute atoms of larger atomic radius were added. Sharma et al 21 reported about the increase in lattice parameter in the case of mechanical milling of pure KCl powder under vacuum.…”