Computer-Aided Thermodynamics of Solid Ternary Fe_(1-x)(Ni_(0.86)Cr_(0.14))_x Alloys by Knudsen Cell Mass Spectrometry

摘要

Knudsen cell mass Spectrometry has been employed to investigate thermodynamically the fcc solid ternary Fe_(1-x)(Ni_(0.86)Cr_(0.14))_x alloys. The "Digital Intensity-Ratio" (D.I.R.)-method has been applied for the determination of the tnermodynamic excess properties. Fcc solid ternary Fe_(1-x)(Ni_(0.86)Cr_(0.14))_x alloys are characterized by negative molar excess Gibbs energies G~E, negative molar excess entropies S~E, and exothermic molar heats of mixing H~E. At 1673 K the minimum H~E value is -2830 J/mol (28 at.% Fe), the minimum G~E value is -2390 J/mol (29.5 at.% Fe), and the minimum S~E value is -0.27 J/(mol K) (28 at.% Fe). At 1673 K the ther-modynamic activities of Fe show slight negative deviations from the ideal behavior for alloys with a Fe-content of less than 70 at.%, and ideal behavior for the Fe-rich alloys (x_(Fe) > 0.7).