CALORIMETRIC MEASUREMENT OF LIQUID ALUMINUM-LITHIUM-ZINC ALLOYS

The enthalpy of mixing of liquid Al-Li-Zn ternary alloys was measured in the 729-955 K range using a high temperature mixing calorimeter. An association model is used to calculate the thermodynamic mixing funct ions of the ternary alloys on the basis of the enthalpy of mixing of t he base binary systems. The calculated enthalpy of mixing shows in the region around the ternary p-phase lower negative values than the meas ured ones. The existence of ternary phases and the possibility to obta in metastable quasicrystals by rapid solidification show that these de viations are caused by additional ternary interactions. These ternary interactions are correlated with a value of 1.8 of the mean number of conduction electrons per atom. (C) 1997 Elsevier Science B.V.