Calorimetric measurements of liquid (Al + Li + Zn) alloys

Highlights: • Calorimetric measurements of binary (Al + Li) system. • Integral enthalpies of mixing of liquid (Al + Li) alloys at T = 1023 K and T = 1027 K. • Calorimetric measurements of ternary (Al + Li + Zn) system. • Integral enthalpies of mixing of liquid (Al + Li + Zn) alloys. - Abstract: The integral molar enthalpies of mixing are described by drop calorimetry for liquid alloys based on the (Al + Li) and (Al + Li + Zn) system, with the use of the Setaram MHTC 96 Line Evo calorimeter. The measurements for the (Al + Li) system were carried out at two temperatures, 1023 K and 1027 K, and compared with the literature data. The integral molar enthalpies of mixing of the liquid binary system over the entire concentration range have negative values. Moreover, for the mole fraction of lithium (X_Li = 0.5053), the minimum value of the integral enthalpy of mixing of the (Al + Li) system is equal to Δ_mixH_m = −12.1 kJ · mol⁻¹. The experimental studies for the (Al + Li + Zn) system involved measurements at three different temperatures: 942 K for the (Al_0.90Li_0.10)_1−xZn_x alloy composition; 978 K for the (Al_0.35Li_0.65)_1−xZn_x and (Al_0.65Li_0.35)_1−xZn_x alloy composition and finally, 1014 K for the (Al_0.50Li_0.50)_1−xZn_x alloy composition. This work presents a complete study of mixing enthalpies in (Al + Li) and (Al + Li + Zn) systems and may therefore provide reference for earlier attempts on calorimetric measurements of the (Al + Li + Zn) system.