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have been obtained from electromotive force (EMF) measurements, in the temperature range 950 to 1150 K, using the following galvanic cells with CaF 2 single crystals as the electrolyte:Cr, CrF 2 |CaF 2 | CrF 2 , Cr 3 C 2 , C (950 to 1150 K) Extreme precautions were taken during the experimental measurements to avoid errors. The reliability and reproducibility of the values were confirmed by careful repetition of several of the experiments. The following equation has been obtained by a linear analysis of the EMF results as a function of temperature:The generated values are compared with those reported in the literature.The values of the enthalpy of formation were evaluated by using a third-law analysis, and an average value of was obtained. The ground-state energy of the hypothetic end-member compound CrC 3 in the bcc structure at 0 K was calculated by using the ab initio method. The experimental results obtained, as well as the results from the ab initio calculations, were employed in a reassessment of the Cr-C system using the CALPHAD approach. A new set of parameters for the bcc phase was evaluated using first-principles calculations.⌬ f H°2 98 ϭ Ϫ71.7 kJ>mol ⌬ f G°C r 3 C 2 (Ϯ1600) ϭ Ϫ58,857 Ϫ22.344T (J # mol Ϫ1 ) (950 to 1150 K)

An extensive thermodynamic investigation of the Al – Ni – Si system is carried out via an integrated approach of calculation of phase diagrams, first-principles calculations, and key experiments. Eighteen decisive alloys are prepared in order to verify the existence of the previously reported ternary compounds and to provide new phase equilibrium data. Phase compositions, microstructure, and phase transition temperatures are determined using the combined techniques of X-ray diffraction, scanning electron microscopy, energy dispersion X-ray analysis, and differential thermal analysis. The order/disorder transition between disordered bcc_A2 and ordered bcc_B2 phases as well as that between disordered fcc_A1 and ordered L12 phase are described using a two-sublattice model. A self-consistent parameter set is finally obtained by considering the huge amount of experimental data including 13 vertical sections and 5 isothermal sections from both the literature and the present experiments. Almost all of the reliable phase diagram data can be well described by the present modeling. The reliability of the calculated thermodynamic properties for ternary phases is verified through enthalpy measurement employing drop calorimetry and first-principles calculations. The thermodynamic parameters obtained can also successfully predict most of the thermodynamic properties and describe the solidification path for the selected as-cast alloy Al6Ni55Si39.

The molar volume of fcc phase in the Ni-Cr-Mo system has been evaluated by means of the CALPHAD approach based on experimental data from the literature. The molar volumes of the non-stable fcc Cr and Mo were determined by extrapolating volume data from several stable solid solutions combined with the first-principles calculation results. A set of parameters has been obtained and can give a reasonable description of most experimental data on molar volume.