Determination of thermophysical and thermodynamic properties, of Ag-Mg alloys
S. Terlicka, A. Dębski, Anna Sypień, W. Gąsior, A. Budziak
Abstract
The main purpose of this work was pioneering dilatometric measurements of alloys and intermetallic phases of the Ag-Mg system and experimental determination of the standard enthalpy of formation of alloys and intermetallic phases of this binary system, including for the first time alloys above 60 at% Mg. The scope of the work included the preparation of two alloys containing 40 and 60 at% of Mg and intermetallic phases (Ag3Mg, AgMg, ε- AgMg3 and AgMg4) from high purity Ag and Mg and their qualitative and quantitative structural analysis using X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM/EDS). The produced and characterized alloys have been subjected to dilatometric studies in the temperature range from room temperature up to 833 K and measurements of change of the standard enthalpy of formation by solution calorimetric method in a liquid tin as a metallic bath. The addition of Mg to Ag generally increased the linear coefficient of thermal expansion compared to pure silver. The standard enthalpies of formation of the prepared alloys were consistent with literature data, and the observed maximum differences were c.a. 1.7 kJ/mol at.