A thermodynamic study of copper-iron and copper-cobalt liquid alloys by mass spectrometry
Tóm tắt
The thermodynamic activities in the liquid Cu-Fe and Cu-Co binary systems were measured by a high temperature mass spectrometric technique. From the obtained data, the heats of mixing in the Cu-Co liquid binary were calculated. Both the Cu-Fe and Cu-Co systems are thermodynamically similar, with large positive deviations from ideality in the activities. The activity coefficients in the liquid Cu-Co system at 1823 K were found to be symmetrical and can be expressed by lnγCu= 1.76X
Co
2
The heat of mixing in the liquid Cu-Co system was found to be described by a cubic function δHm = −17.9
Co
3
− 7.6X
Co
2
+ 25.5Co (kJ/mol) The activity coefficients in the liquid Cu-Fe system at 1873 K were found to satisfy two quadratic formalisms in the binary In γCu = 2.10X
Fe
2
− 0.13 0.65 ≤X
Fe ≤ 1 In γFe = 1.79X
Cu
2
+ 0.04 0 ≤X
Fe
≤ 0.65
Tài liệu tham khảo
A. Neckel and S. Wagner:Ber. Bunsenges. Phys. Chem., 1969, vol. 73, p. 210.
G. R. Belton and R. J. Fruehan:J. Phys. Chem., 1967, vol. 71, p. 1403.
L. N. Sidorov:Dokl.Akad. Nauk, 1967, vol. 176, p. 1351.
R. A. Hultgren and P. D. Desai:Selected Thermodynamic Values and Phase Diagrams for Copper and Some of Its Binary Alloys, Incra Monograph I, Int’l. Copper Research Assoc, Inc., 1971.
J. P. Morris and G. R. Zellars:J. Met., 1956, vol. 8, p. 1086.
U. V. Choudary, J. A. Serkin, and G. R. Belton:Met. Trans. B, 1975, vol. 6B, p. 399.
Y. Iguchi, Y. Tozaki, M. Kakizaki, S. Ban-ya, and T. Fuwa:Tetsu-to-Hagane, J. ISIJ, 1977, vol. 63, p. 953.
JANAF Thermochemical Tables, Second Edition, Dow Chemical Company, Midland, Mich., 1970.
R. N. Dokken and J. F. Elliott:Trans. TMS-AIME, 1965, vol. 233, p. 1351.