THE MIXING ENTHALPY OF THE TERNARY (PH, SN, ZN) LIQUID-PHASE - CALORIMETRIC MEASUREMENTS AND MODELING OUTSIDE AND INSIDE THE MISCIBILITY GAP

Calorimetric measurements were carried out at 444 degrees C, right abo ve the Zn melting temperature. At this temperature, the system present s an extensive miscibility gap especially near the binary (Pb, Zn) bor der since the two-phase region is contained between appoximatively 0.0 6 at.% Zn and 0.995 at.% Zn. Modelling was performed with a limited se t of data consisting of our own calorimetric measurements in the two b inary (Pb, Sn) and (Sn, Zn) liquid phases (over the entire composition range), into three ternary isopleths outside the miscibility gap, and in the monophase Pb rich region inside the binary (Pb, Zn) system.