| 1. |
- Bogdanov, V. I., et al.
(författare)
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Chemical and deformational interactions in solid solution of carbon in nickel
- 2012
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Ingår i: Physics of metals and metallography. - 0031-918X .- 1555-6190. ; 113:9, s. 831-835
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Tidskriftsartikel (refereegranskat)abstract
- A first-principles stuy of ordering phenomena in hcp interstitial solid solutions of oxygen and nitrogen in Ti, Zr and Hf has demonstrated that the dominant contributions to the interaction energy of interstitial atoms are of chemical nature; thus, it is necessary to modify the previously established concepts about the priority role of deformational interactions in interstitial solutions. We have continued studies of the role of chemical and deformational interactions of interstitial atoms by the example of solid solutions of carbon in nickel. The results obtained also confirm a significant role of chemical interactions between carbon atoms in these solid solutions. The results were compared with the experimental data on the enthalpy of carbon dissolution in nickel and on the coefficient of solutal expansion of the lattice.
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| 2. |
- Bogdanov, V. I., et al.
(författare)
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First-principles investigations of interatomic interactions in Ni3Al alloyed by interstitial and substitutional impurities
- 2013
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Ingår i: Physics of metals and metallography. - 0031-918X .- 1555-6190. ; 114:3, s. 191-196
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Tidskriftsartikel (refereegranskat)abstract
- First-principles calculations of the total energy of interstitial and substitutional solid solutions in intermetallic compound Ni3Al were performed based on methods using Vienna ab-initio simulation package (VASP). The results of the calculations for interstitial solutions of carbon in Ni3Al confirmed the priority role of chemical interactions over deformational ones for the nearest neighbors. We attempted to use first-principles methods of calculation of the deformation interaction and continuum approaching in the theory of solutions to calculate coefficients of the concentration changes of the lattice spacing. Comparison of the calculation results with experimental data of substitutional impurities in Ni3Al has shown that the proposed method can aid in the study of the distribution of impurity atoms on the sublattices of the ordered phases, intermetallic compounds. We have proposed a method of calculating the partial molar volume of impurity in interstitial solid solutions.
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| 3. |
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| 4. |
- Ruban, Andrei V., et al.
(författare)
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First-principles study of point defects in Ni3Al
- 2014
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Ingår i: Philosophical Magazine. - : Informa UK Limited. - 1478-6435 .- 1478-6443. ; 94:1, s. 20-34
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Tidskriftsartikel (refereegranskat)abstract
- The energetics and structural properties of native, substitutional and interstitial defects in Ni3Al have been investigated by first-principles methods. In particular, we have determined the formation energies of composition conserving defects and established that the so-called penta defect, which consists of four vacancies on Ni sublattice and Ni antisite on the Al sublattice, is the main source of vacancies in Ni3Al. We show that this is due to the strong Ni-site preference of vacancies in Ni3Al. We have also calculated the site substitution behaviour of Cu, Pd, Pt, Si, Ti, Cr, V, Nb, Ta and Mo and their effect on the concentration expansion coefficient. We show the latter information can used for an indirect estimate of the site substitution behaviour of the alloying elements. The solution energy of carbon and its effect on the lattice constant of Ni3Al have been obtained in the dilute limit in the first-principles calculations. We have also determined the chemical and strain-induced carbon-carbon interactions in the interstitial positions of Ni3Al. These interactions have been subsequently used in the statistical thermodynamic simulations of carbon ordering in Ni3Al.
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