Diffusion rates of 3d transition metal solutes in nickel by first-principles calculations

Krčmar, Maja; Fu, C. L.; Janotti, Anderson; Reed, Roger C.

doi:10.1016/j.actamat.2005.01.044

Cited by 97 publications

(75 citation statements)

References 8 publications

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“…This can be attributed to the work of Janotti et al [31] using the ultrasoft pseudopotential method [15], because the PAW [16] method used in the present work reconstructs the exact valence wave function with smaller core radii than the ultrasoft potentials, making the PAW a little more computationally expensive, but also more accurate. The previous studies on solute diffusion in Ni showed that there was no direct correlation between the activation energy barrier for diffusion and size of the impurity element [2,31], results that are reproduced in the present work. The present work also shows that in general, 5d elements consistently have higher activation energies than the corresponding 4d element in the same row, while that trend does not hold for 3d elements.…”

Section: Diffusion Coefficient Calculationsupporting

confidence: 82%

“…For the sake of simplicity and efficiency, D 0 can be estimated by treating the vibrational degrees of freedom near the saddle point as nearly simple harmonic oscillators [32]. This value was found to be on the order of 10 -5 m 2 /s for the dilute diffusion of transition metals in Ni [2,31]. Thus, 10 -5 m 2 /s will be used for the diffusion prefactor in this work as an approximation, a value that well represents the experimental diffusion prefactor of pure Ni (8.5×10 -5 -17.7×10 -5 m 2 /s [33][34][35]).…”

Section: Diffusion Coefficient Calculationmentioning

confidence: 99%

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Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

Zacherl¹,

Shang²,

Kim³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

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To understand the effects of alloying elements on the creep rate of Ni-base superalloys, factors entering into a secondary creep rate are calculated via first-principles calculations based on density functional theory for 26 Ni 31 X systems where X = Al, Co, Cr, Cu, Fe, Hf, Ir, Mn, Mo, Nb, Os, Pd, Pt, Re, Rh, Ru, Sc, Si, Ta, Tc, Ti, V, W, Y, Zr, and Zn. They are volume, elastic properties, stacking fault energy, and diffusivity. It is found that shear modulus, Young's modulus, and roughly stacking fault energy show inverse correlation to the atomic volume of the system. In addition, the closer the alloying elements to Ni, with respect to atomic volume and atomic number, the larger the predicted shear modulus, Young's modulus, and stacking fault energy. Diffusivity calculations show that mid-row 5d transition metal elements, particularly Re, Os, and Ir, have the highest activation barrier for diffusion, while far-right or far-left row placement elements such as Y, Zn, and Hf, have the lowest activation energy barriers for diffusion. A creep rate ratio of ߝሶ ே యభ ߝሶ ே ⁄ is calculated and the effect of the alloying elements shows 13 systems have a decreased creep rate relative to Ni, while 13 systems have an increased creep rate relative to Ni.

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Section: Diffusion Coefficient Calculationsupporting

confidence: 82%

Section: Diffusion Coefficient Calculationmentioning

confidence: 99%

Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

Zacherl¹,

Shang²,

Kim³

et al. 2012

Superalloys 2012 (Twelfth International Symposium)

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“…Similar to the transition metals, 27 atomic size plays a minor role in the vacancy-mediated diffusion of poor metals in α-Ti. Comparing the diffusivities obtained, the largest atom (In, with atomic radius of 1.54 Å) is the fastest diffuser amongst the poor metals, while Si is the slowest diffusing poor metal solute in Ti, although it has a relatively small atomic radius (1.11 Å).…”

Section: A Atomic Size and Solute Diffusionmentioning

confidence: 99%

Diffusion anisotropy of poor metal solute atoms in hcp-Ti

Scotti

Mottura

2015

The Journal of Chemical Physics

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Atom migration mechanisms influence a wide range of phenomena: solidification kinetics, phase equilibria, oxidation kinetics, precipitation of phases, and high-temperature deformation. In particular, solute diffusion mechanisms in α-Ti alloys can help explain their excellent high-temperature behaviour. The purpose of this work is to study self- and solute diffusion in hexagonal close-packed (hcp)-Ti, and its anisotropy, from first-principles using the 8-frequency model. The calculated diffusion coefficients show that diffusion energy barriers depend more on bonding characteristics of the solute rather than the size misfit with the host, while the extreme diffusion anisotropy of some solute elements in hcp-Ti is a result of the bond angle distortion.

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“…This trend was reported by Ding et al [60] and Messina et al [61] also. It has been found for transition-metal (TM) impurities diffusion in fcc Ni as well [53]. The inverse relation between the magnitude of H mig,2 and atomic size has been rationalized through the displacement of the large impurity atom toward the vacancy.…”

Section: B Migration Barriersmentioning

confidence: 96%

“…This is particularly the case for diffusion in iron where an Arrhenius plot does not show a simple linear relation in the ferromagnetic state. Density functional theory (DFT) calculations have proven successful in predicting experimental data such as lattice parameters [46,47], elastic properties [48,49], and energy barriers for diffusion, e.g., diffusivities in aluminum [50], magnesium [51,52], and nickel [53]. Many impurity diffusivities in bcc iron [54][55][56][57][58][59][60][61] have been calculated with DFT methods, but oftentimes only experimentally fitted data, such as activation energy for diffusion, have been compared with the computed results.…”

Section: Introductionmentioning

confidence: 99%

First-principles analysis of solute diffusion in dilute bcc Fe- X alloys

2017

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The diffusivities of substitutional impurity elements in iron have been computed with ab inito electronic density functional techniques, using exchange-correlation functional PW91. Excess entropies and the attempt frequency for a jump were determined by calculating phonon frequencies in the harmonic approximation. The influence of the degree of spontaneous magnetization on diffusivity is taken into account by means of the Girifalco model. The activation energy for diffusion has been determined by computing the vacancy formation energy, impurity-vacancy binding energies, migration barrier energies, and the effective energy associated with correlation of vacancy-mediated jump. For each type of impurity atom these contributions have been evaluated and analyzed up to and including the fifth nearest-neighbor shell of the impurity atom. It is found that impurities that have a low migration energy tend to have high effective energy associated with vacancy migration correlation, and vice versa, so that the total diffusion activation energies for all impurities are surprisingly close to each other. The strong effect of vacancy migration correlation is found to be associated with the high migration energy for iron self-diffusion, so that movement of vacancies through the iron bulk is in all cases, except cobalt, the limiting factor for impurity diffusion. The diffusivities calculated with the PW91 functional show good agreement with most of the experimental data for a wide range of elements.

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Diffusion rates of 3d transition metal solutes in nickel by first-principles calculations

Cited by 97 publications

References 8 publications

Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

Effects of Alloying Elements on Elastic, Stacking Fault and Diffusion Properties of Fcc Ni from First-principles: Implications for Tailoring the Creep Rate of Ni-base Superalloys

Diffusion anisotropy of poor metal solute atoms in hcp-Ti

First-principles analysis of solute diffusion in dilute bcc Fe- X alloys

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