Phase equilibria in the ternary Ag-Au-Ga system: Isothermal sections at 250°C and 450°C

The ternary Ag-Au-Ga system seems to be interesting in jeweller’s craft as a joint. Moreover, the ternary systems based on gold and silver have found applications in the dental industry. A literature overview of the Ag-Au-Ga system shows that the information about phase equilibria of this system does not exist. In the present work, phase equilibria in the Ag-Au-Ga ternary system have been studied by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) analysis and X-ray diffraction analysis (XRD). Twenty two annealed alloys in the 10-70 at.% Ga region have been investigated. Obtained experimental results were compared with the predicted isothermal sections at two temperatures (250°C and 450°C). No ternary compounds are found

Activity and diffusivity of oxygen in the liquid dilute BixSb1-x solutions

The diffusivity and activity coefficient of oxygen in liquid antimony, bismuth and antimony-bismuth alloys were determined from coulometric titration experiments, which were performed in the temperature range from 985 to 1185 K. The diffusivity in pure metals (in cm2/s) is: Dbi,O =(9.04 ± 1.82)∙10-3 exp (-49115±1809/RT) DSb,O(2.87±0.22)∙10-4 exp (-16720±677/RT). The standard free energy of solution of oxygen in liquid antimony, bismuth and antimony-bismuth alloys according to the reaction ½ O2 (g) = O (infinite dilution) is calculated. The activity coefficient of oxygen was calculated at 1085 K as a function of the alloy composition. It was demonstrated that Wagner's model with one adjustable parameter h gave a satisfactory description of the experimental data

Właściwości termodynamiczne i równowagi fazowe w układzie trójskładnikowym Cu-Pb-Fe

Using experimental data available in the literature, two binary systems, namely Cu-Pb and Fe-Pb were recalculated. Next, accepting Cu-Fe phase diagram assessment as given by Ansara and Jansson, the ternary Cu-Fe-Pb system was analyzed. Calculated equilibrium lines and thermodynamic functions are compared with existing experimental data. Good agreement was found between the calculated diagram and the experimental results. Having the system optimized, functional dependences of the logarithms of the activity coefficients on temperature and concentrations for Cu, Fe and Pb in the liquid solution are given.Dwa układy podwójne Cu-Pb oraz Fe-Pb zostały powtórnie zoptymalizowane używając danych eksperymentalnych dostępnych w literaturze. Następnie, akceptując optymalizacje układu Cu-Fe opublikowana przez Ansare i Janssona, poddano analizie trójskładnikowy układ Cu-Pb-Fe. Obliczone linie równowagi faz oraz funkcje termodynamiczne zostały porównane z dostępnymi danymi eksperymentalnymi. Uzyskano dobrą zgodność pomiędzy policzonym układem a danymi eksperymentalnymi. Korzystając z wyników optymalizacji, zostały podane zalezności logarytmu współczynnika aktywności w funkcji temperatury oraz Cu, Fe i Pb w funkcji stężenia dla w roztworze ciekłym

Phase relations near ternary eutectic point in the Ag-In-Sb system

The results of the phase relations near ternary eutectic point in the Ag-In-Sb system are investigated in this paper. Phase equilibrium calculation was done using Thermocalc software and experimental DTA results for the chosen alloys in the isopleths with molar ration of In:Sb = 7:3; 9:1 and 1:1. The structural characteristics of these alloys have been investigated using light optic microscopy and scanning electron microscopy, while hardness measurements have also been done. Solidification path for three ternary alloys located on three different investigated isopleths was calculated using Pandat software