ON THE ALGEBRAIC EVALUATION OF THE TERNARY MOLAR HEAT OF MIXING H-E FROM CALORIMETRIC INVESTIGATIONS

The experimental effort of calorimetric investigations on ternary allo y systems is very large and evaluation of the measured data is very ti me-consuming. A considerable reduction both of the time spent on evalu ation and of the experimental work can be expected by applying the new overall best-fit technique developed in this work. The suggested eval uation technique is based on the ternary ''Thermodynamic Adapted Power '' (TAP)-series, requires computer assistance, but it makes possible t o determine ternary molar heat of mixing H-E by means of a minimum of experimental investigations: If there exist accurate H-E-data of the t hree binary boundary systems, only a small number (about 5 to 10) of t ernary H-E-values must be determined. The application of the proposed evaluation technique is illustrated with data for liquid Fe-Co-Ti, Fe- Ni-Ti, Fe-Ni-Zr, and Cu-Sn-Ni ternary alloys. The advantages of the pr oposed technique are discussed in detail.