No abstract

The surface tension and viscosity of Cu–Fe–Si ternary alloys were computed at different temperatures using thermodynamic approaches. The thermodynamic data of the alloy were optimized in the framework of the Redlich-Kister (R–K) polynomials and exponential temperature dependent coefficients of the R–K polynomial were obtained. These coefficients were used to compute the excess Gibbs free energy of mixing of the alloy and the partial excess free energy of the components. The partial excess free energy so obtained was used to compute the surface tension of the ternary Cu–Fe–Si alloy system and its binary sub-systems. The enthalpy of mixing was also optimized and it was used to compute the viscosity of the sub-binary and ternary alloys.

The compositional dependence of thermo-physical properties of Si-Ti liquid alloy has been reassessed using different modeling equations at temperatures 2000 K, 2400 K and 2473 K. The thermodynamic and structural properties of the system have been computed in the frame work of quasi-lattice test. The extent of surface segregation and surface tension of the liquid mixture have been computed using Butler’s equations at afore mentioned temperatures. The results so obtained have been compared with the available literature database. Theoretical investigations shows that the compound forming tendency of the system gradually decreases at elevated temperatures and hence it shows ideal behaviours, as expected. BIBECHANA 17 (2020)

Thermodynamic and surface properties of the ternary Ti–Si–Fe liquid alloy have been assessed at temperatures 1873 K, 1973 K, 2073 K and 2173 K. For this purpose, the optimized linear temperature dependent coefficients of Redlich–Kister (R–K) polynomials for excess free energy of mixing for sub-binary systems Ti–Si, Fe–Si and Ti–Fe have been computed considering available experimental and literature data. The thermodynamic properties of ternary liquid alloy, such as activity have been studied using general solution model (GSM) and excess free energy of mixing has been studied using GSM, Kohler and Toop models. In surface properties, surface concentration has been computed using Butler’s equation and surface tension of the liquid alloy has been studied using all the four above mentioned models feeding the database of liquid Fe–Si, Si–Ti and Ti–Fe sub-binary systems. The values of surface tension computed using GSM and Toop model are in well agreement with each other at all concentrations. Moreover, the computed values of excess free energy of mixing and surface tension decrease at elevated temperatures from all corners and at all considered cross-sections indicating the decrease in ordering tendency of the alloy.

Thermo-physical properties of Al-Mg alloys in molten state at 1073 K have been studied using thermodynamic modeling. Thermodynamic properties, such as free energy of mixing, heat of mixing, entropy of mixing, activities and structural properties, such as concentration fluctuation in long wavelength limit, Warren-Cowely short range order parameter have been studied at 1073 K, 1173 K, 1273 K and 1373 K on the basis of regular associated solution model. The surface properties such as surface concentrations and surface tension of the liquid alloys have been studied by using Butler's model. A consistent set of model parameters have also been obtained by using optimization procedure based on statistical thermodynamics. Our analysis reveals that Al-Mg alloy is moderately interacting and it shows ordering nature at 1073 K. The nature of the alloys changes from ordering to segregating as the temperature increases.