Thermodynamics of the liquid Co-Cu system and calculation of phase diagram

Knudsen-cell mass spectrometric measurements have been carried out in the l iquid phase of the Co-Cu system in the concentration range 25.0 to 85.9 at. % Cu in the temperature range 1347 to 1587 degrees C. The molar excess Gib bs energy, enthalpy and entropy of mixing, as well as the thermodynamic act ivities of components in the liquid Co-Cu system were determined using the composition and temperature dependence of the ratio of intensities of Co-59 and (CU)-C-63 ions. The results show that a sub-regular solution model wou ld fit measured data well (2-parameter thermodynamically adapted power (TAP ) series: C-n(H) in J.mol(-1); C-1(H)= 35,961, C-2(H) = -5573.2; C-n(S) in J.mol(-1.K-1); C-1(s) = 5.54, C-2(s) = -3.35), A special experiment verifie d solid-liquid phase equilibrium at 1327 degrees C and the phase diagram wa s calculated.