Thermodynamic mixing functions and phase equilibria in the nickel-chromium system by high-temperature knudsen cell mass spectrometry

Thermodynamic excess functions of nickel-chromium alloys in the body-centered cubic (bcc) phase have been investigated by computer-aided Knudsen cell mass spectrometry in the tem-perature range of 1300 to 1650 K. Activities, as well as molar excess Gibbs energies, enthalpies, and entropies, were obtained from the ion intensities as a function of composition by fitting to a subregular solution model [2-parameter thermodynamically adapted power (TAP) series:C ^H _n in J/mol,C ^H ₁ = 3900,C ^H ₁ = 44,610;C ^S _n in J/mol-K,C = 9.71, c= 13.52]. Based upon these data, the phase diagram has been recalculated.