Experimental investigation and thermodynamic calculations of the Ag-Bi-Ga phase diagram

Abstract

Phase diagram of the Ag-Bi-Ga ternary system was investigated using differential thermal analysis (DTA), scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS), and x-ray powder diffraction (XRD) methods. Experimentally obtained results were compared with the results of thermodynamic prediction of phase equilibria based on calculation of phase diagram (CALPHAD) method. Phase transition temperatures of alloys with overall compositions along three selected vertical sections Ag-Bi50Ga50, Bi-Ag50Ga50 and Ga-Ag50Bi50 were measured by DTA. Liquidus temperatures were experimentally determined and compared with the results of thermodynamic calculation. Identification of coexisting phases in samples equilibrated at 200 degrees C was carried out using SEM-EDS and XRD methods. Obtained results were compared with the calculated isothermal section of the Ag-Bi-Ga ternary system at corresponding temperature. Calculated liquidus projection and invariant equilibria of the Ag-Bi-Ga ternary system were presented. The obtained values were found to be in a close agreement.