Thermodynamic evaluation of the Co–Sc and Fe–Sc systems

Liu, X.J.; Yu, Peng; Wang, C.P.; Ishida, K.

doi:10.1016/j.jallcom.2007.11.069

Cited by 18 publications

(16 citation statements)

References 11 publications

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“…1 that our results do not confirm the data from modeling [10], especially at x Sc > 0.3, where the authors [10] erroneously predicted overly exothermal effects of mixing of the melts, with the minimum shifted towards Sc. As the only point from [9] at x Sc = 0.15 was taken by the authors [10] to construct their model, the latter is incorrect due to reckless extrapolation.…”

Section: Discussioncontrasting

confidence: 99%

“…The only attempt to systematize all known thermodynamic properties of alloys of the Co-Sc system was made in the work [10], where the following concentration dependences of the enthalpies and excess entropies of mixing of these melts were obtained: However, these results are supported mostly by the data [9], which have too narrow concentration range. A shift of the minimum of the integral mixing enthalpies towards scandium is doubtful, as well as too exothermal value of the partial enthalpy of cobalt at its infinite dilution: -160 kJ/mol, from [10].…”

Section: The Co-sc Systemmentioning

confidence: 99%

“…A shift of the minimum of the integral mixing enthalpies towards scandium is doubtful, as well as too exothermal value of the partial enthalpy of cobalt at its infinite dilution: -160 kJ/mol, from [10]. Consequently, the thermodynamic properties of these melts 1 The article was translated by the authors.…”

Section: The Co-sc Systemmentioning

confidence: 99%

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Thermodynamic properties of alloys of the Co-Sc and Co-Y systems

Shevchenko

Иванов

Berezutski

et al. 2015

Russ. J. Phys. Chem.

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The thermochemical properties of melts of the Co-Sc(Y) systems were studied by the calorimetry method at 1873 K over the wide concentration intervals. It was shown that moderate negative heat effects of mixing are characteristic for these melts. Using the ideal associated solution (IAS) model, the activities of components, mixing Gibbs energies and entropies in the alloys of these systems, and their phase diagrams were calculated, and they agree well with the data from literature and undergo the general dependences for the Fe(Co, Ni, Cu)-d-metal systems.The alloys containing cobalt, which are the base of most heat-resistant and structural materials, are used in aircraft industry, turbine construction, and other important fields of the national economy. As magnetic and high-temperature materials, they have valuable applications in many areas. That is why goods made of them demand high-grade alloys. As the quality of solid alloys is mostly imprinted at the casting stage, both manufacturing and welding of the cobalt alloys need optimal, scientifically based techniques, oriented towards their physicochemical properties.The Co-Y alloys are promising materials with a wide range of unique physical and mechanical properties (particularly, a class of cobalt-containing compounds with rare-earth elements provides significant interest owing to their outstanding magnetic properties). It is known that multicomponent alloys based on the binary Co-Y system (for instance, Al-Co-Y) at certain compositions can be obtained in amorphous state [1,2]. To search these compositions, it is important to know the thermodynamic properties of the melts. Scandium has high durability, hardness, atmosphere-proof qualities, and even in small quantities it gives a set of those valuable properties to the aluminum-based alloys [3], which can also contain cobalt. To develop the most rational methods of obtaining and exploiting these alloys, as well as the Co-Sc(Y)-metal alloys, the precise information on their thermodynamic features is needed. THE Co-Sc SYSTEMThe phase diagram of the Co-Sc system was for the first time constructed in [4], where the phase equilibria in the composition range 0 < x Sc < 0.8 were studied, and then it was revised in the works [5][6][7].Accordingly to [8], the enthalpy of formation of the Co 2 Sc intermetallic is -32.5 kJ/mol at., and of the CoSc 2 -26.7 kJ/mol at. These values were obtained by direct synthesis calorimetry at 1473 K.In [9] the authors investigated the mixing enthalpies of the Co-Sc system at 1873 K in the range 0 < x Sc < 0.15. At x Sc = 0.15, the integral mixing enthalpy was found to be -13.2 ± 0.3 kJ/mol.The only attempt to systematize all known thermodynamic properties of alloys of the Co-Sc system was made in the work [10], where the following concentration dependences of the enthalpies and excess entropies of mixing of these melts were obtained: However, these results are supported mostly by the data [9], which have too narrow concentration range.

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Section: Discussioncontrasting

confidence: 99%

Section: The Co-sc Systemmentioning

confidence: 99%

See 1 more Smart Citation

Thermodynamic properties of alloys of the Co-Sc and Co-Y systems

Shevchenko

Иванов

Berezutski

et al. 2015

Russ. J. Phys. Chem.

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“…In order to understand how the 3d transition elements provide different properties to the Fe-based alloys, having knowledge about the effect of these elements on the fundamental properties of α-Fe is essential. Although, a large number of theoretical studies concerning to the electronic structure and magnetic properties of dilute alloys of TM in α-Fe have been reported [13][14][15][16][17][18][19][20][21][22][23] , in a small number of these studies the atomistic simulation was based on the DFT. The DFT is one of the most important quantum-mechanical methods used in Chemistry and in Physic to calculate the electronic structure of atoms, molecules and solids…”

Section: Introductionmentioning

confidence: 99%

Electronic Effect of V, Ti, and Sc Impurities on the Hyperfine Interactions of Fe Atoms in α-Fe: A First Principles Study

Pérez

Santos

2017

Mat. Res.

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The Linearized Augmented Plane Wave method, as implemented in the Wien2k computational code, was used to investigate the effects of the 3d transition metals (TM) Sc, Ti, and V impurities on the hyperfine interaction of iron atoms in α-Fe. The calculation results of this study suggest that the introduction of a TM (TM = Sc, Ti, and V) impurity into α-Fe increases the size of the lattice as well as alters the electronic charge distribution between the atoms in the lattice and at the atomic sphere of the host Fe atoms. The increase of the lattice disturbs the position of the iron atoms and the change on the electronic distribution disturbs the hyperfine interactions at all iron nuclei. The disturbances on the hyperfine magnetic field, isomer shift and electric field gradient at the iron nuclei depend on its relative location to the impurity atom.

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“…Recently, our group has been focused on developing a thermodynamic database of the phase diagrams in the Co-based alloys [13][14][15][16][17][18][19][20][21]. In order to obtain the detailed information of phase equilibria for the thermodynamic assessment, the objective of the present work is to experimentally determine the isothermal sections at 1300 • C, 1200 • C, 1100 • C and 1000 • C using the equilibrated ternary alloys, which will meet the need for the thermodynamic description of the Co-Fe-Zr ternary system and provide a better understanding of microstructures of promising alloys for practical applications.…”

Section: Introductionmentioning

confidence: 99%