The enthalpy of formation and the heat capacity of liquid Cu-La-Ni alloys

The integral enthalpy of mixing of liquid Cu-La-Ni alloys was determined by solution calorimetry at 1123 K. An adiabatic calorimeter was used to measure the heat capacity of liquid Cu25La50Ni25. The association model was applied to calculate the thermodynamic functions of liquid Cu-La-Ni using the model parameters of the three limiting binary alloys. The results show systematic positive deviations from the experimental data. An additional ternary association reaction was assumed with a stoichiometry near to the composition of maximum deviation between calculation and experiment. The new description leads to good agreement with the experimental data. (C) 1999 Elsevier Science S.A. All rights reserved.