Enthalpy of Mixing of Liquid Cu-Fe-Zr Alloys at 1873 K (1600 °C)

The enthalpies of mixing of liquid Cu-Fe-Zr alloys were determined at 1873 K (1600 °C) by using a high-temperature isoperibolic calorimeter. The measurements were performed along sections xCu/xFe = 3/1, 1/1, 1/3 in the composition range xZr = 0 to 0.55. The limiting partial enthalpies of mixing of undercooled liquid zirconium in liquid Cu-Fe alloys are (–91.8 ± 8.4) kJ mol−1 (section xCu/xFe = 3/1), (–94.1 ± 12.8) kJ mol−1 (section xCu/xFe = 1/1), and (–107.3 ± 15.6) kJ mol−1 (section xCu/xFe = 1/3). The integral mixing enthalpies are sign changing over the investigated composition range. The Redlich–Kister–Muggianu polynomial was used for the least square fit of the experimental results in order to obtain an analytical expression for the integral mixing enthalpy.