Dragan Manasijević

Comparative thermodynamic study and phase equilibria of the Bi-Ga-Sn ternary system

Abstract The results of a comparative thermodynamic investigation of the Bi – Ga – Sn system, giving experimentally obtained results and calculated thermodynamic data, are presented in this paper. Oelsen calorimetry was performed for the experimental determination of thermodynamic properties in the section with a molar ratio of Bi: Sn = 1: 3, while the Redlich – Kister – Muggianu method was applied for thermodynamic predicting in the sections with molar ratio Bi: Sn = 1: 3, 1: 1, 3: 1. Thermodynamic parameters – partial and integral molar quantities, as well as gallium activities, were determined at the temperatures of 873 and 973 K. Phase equilibria in the Bi – Ga – Sn ternary system have been studied experimentally – using differential thermal analysis and scanning electron microscopy with energy dispersive X-rays, while the calculation of phase diagram was done according to the CALPHAD method. The phase diagram of the section with molar ratio of Bi: Sn = 1: 3 is given, as well as the phase diagram of the ternary Bi – Ga – Sn system at 373 K.

Thermodynamic study of Ga-Sn and Ga-Zn systems using quantitative differential thermal analysis

The results of quantitative differential thermal analysis application in thermodynamic investigation of two gallium-based binary systems, Ga-Sn and Ga-Zn, are presented in this paper. Integral molar enthalpies of mixing in liquid state, as well as the activities, activity coefficients, and other partial and integral molar quantities were determined at the temperatures of 1000, 1073 and 1200 K (for Ga-Sn system) and 723 K (for Ga-Zn system). Obtained results were compared with literature data and comparison showed good agreement. Also, phase diagrams for the investigated simple eutectic systems were confirmed based on DTA curves and compared with literature.

Thermal study and mechanism of Ag2S oxidation in air

The results of thermal study and mechanism of the oxidation process of synthetic Ag2S in air are presented in this article based on the comparative analysis of DTA and XRD results, as well as by constructed phase stability diagrams (PSD) for the Ag–S–O system.

Comparative thermodynamic analysis and phase diagram prediction of the Ga-Sn-Zn system

Abstract The results of comparative thermodynamic analysis and phase diagram prediction of the Ga – Sn – Zn system are presented in this work. The thermodynamic study was done experimentally – using Oelsen calorimetry, for the section Ga – SnZneut, and analytically – according to the general solution model, for the whole system. Main thermodynamic quantities – integral and partial molar Gibbs excess energies, activities and activity coefficients were calculated over a wide temperature range. Additionally, the phase diagram of the section Ga – SnZneut was investigated using differential thermal analysis and predicted using the CALPHAD method. Comparison with available literature data showed reasonable agreement. The liquidus projection of the ternary Ga – Sn – Zn was also calculated.

Mineralogical transformations in copper concentrate roasting in fluo-solid reactor

This work presents the results of investigation process of copper concentrate roasting in fluo-solid reactor with the aim of studying a transformation degree of primary ore minerals under various technological parameters. Input material (charge) and roasting products (calcine) were investigated by x-ray diffraction, ore microscopy and chemical analysis. The investigation results have shown that reaction of mineral transformation are not completed, i.e. they are developed only partially (12-22%) what is a consequence of insufficient long heating, unsuitable temperature or unfilled other parameters as well as non-uniform grain size. .

Activity measurements of Ga in liquid Ga - Tl alloys by EMF method with zirconia solid electrolyte

Abstract Electromotive force measurements (EMF) of an electrochemical cell with zirconia as solid electrolyte were performed to determine the Ga activity from 973 to 1273 K in the entire composition range of liquid Ga–Tl alloys. In the whole concentration range, the activity of Ga shows large positive deviations from ideality, and the activity of Tl which is derived by the Gibbs–Duhem equation shows also positive deviation from ideality. The parameters of the Redlich–Kister equation for excess Gibbs energies of mixing are determined from the results obtained in this study which were compared with Chous model calculation.

The Mechanical and Electrical Properties of the Ternary Bi-Ga-Sb System

Abstract The ternary Bi-Ga-Sb system is a potential soldering material. The gallium-based alloy systems are the subject of numerous investigations due to the constant interest of the semiconductor industry. For a more complete characterization of the ternary Bi-Ga-Sb system, alloys from the three vertical sections were investigated using microstructural analysis as well as electrical conductivity and Brinell hardness measurements. The microstructures of the alloys were investigated by light microscopy and scanning electronic microscopy equipped with energy dispersive spectrometry. Isolines of electrical conductivity and hardness for the entire Bi-Ga-Sb system were calculated using regression models. In addition, a thermodynamic assessment of the system has been carried out by calculation of the isothermal section at 100 °C and by description using the CALPHAD method. Experimental and analytical results were found to be in good agreement.

Calorimetric study and phase diagram investigation of the Au–Ga system

Abstract The results of calorimetric study and phase equilibria investigation of the Au–Ga system, in the Ga-rich region, are presented. Calorimetric study was done using Oelsen methodology and partial and integral molar thermodynamic quantities were determined at a temperature of 873 K. Phase equilibria investigations were done experimentally – using differential thermal analysis, light optical microscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy, and theoretically – using the CALPHAD method. Results agree well with available literature data.

Mechanical and Electrical Properties of Alloys and Isothermal Section of Ternary Cu-In-Sb System at 673 K

Abstract Lead-free solders with copper represent possible substitution for standard lead-tin solders. For the complete definition of the properties of the ternary Bi-Cu-In system, there were performed the investigation of micro structures, hardness by Brinel, and electric conductivity of the alloys. In the range of this ternary system, numerous alloys were tested for three vertical sections, with molar ratio Sb : Cu = 1, Cu : In = 1, Sb : In = 1. The micro structures of the alloys were investigated by application of optic microscopy. By application of CALPHAD method, and software package PANDAT 8.1. there were calculated the isothermal cross sections at 298 K and 673 K. The experimentally obtained phase compositions in microstructures are in a good agreement with phases on calculated cross sections.

Phase diagram investigation of the Sn-InxAgyCuz (x:y:z = 7:2:1) section in the Ag-In-Sn-Cu system

Abstract The results of phase diagram investigation and characterization of the Ag-In-Sn-Cu system are presented in this paper. Samples at the In : Ag : Cu = 7 : 2 : 1 vertical section were measured with differential scanning calorimetry, and the obtained transition temperatures were compared with calculated values. From Calphad-type calculation, the phase diagram for Sn-InxAgyCuz (molar ratio x:y:z = 7:2:1) section is constructed. In order to obtain the microstructure of investigated alloys, scanning electron microscopy with energy dispersive X-ray spectroscopy was used.