Thermodynamic assessment of the ternary Cu-Pb-O system
The thermodynamic assessment of the ternary Cu-Pb-O system was carried out by the CALPHAD method. The thermodynamic properties of the phases are described using a compound energy formalism (CEF) for the various solid phases and an ionic two-sublattice model for the liquid. The thermodynamic parameters of the sub-systems Cu-O, Pb-O and Cu-Pb are adopted from recent assessments. Ternary interaction parameters of the liquid phase have been optimized on the base of the selected literature data (phase diagram and activity of oxygen). The ternary system shows a large liquid miscibility gap of peculiar shape, which connects to the miscibility gaps in each of the binary sub-systems. Calculated phase diagrams are compared with the experimental data.