The thermodynamic properties of iron-gold and cobalt-gold alloys have been measured between 750 and 1000° C by an e.m.f. method with ThO2–YO1.5 electrolytes. Results are given for activities, entropies, and heats of mixing across the complete range of composition and the phase diagrams published in Hansen's compilation (M. Hansen and K. Anderko, “Constitution of Binary Alloys”. 1958: New York and London (McGraw-Hill))are shown to be consistent with the thermodynamic results now obtained. It is concluded that the heat-of-mixing term is the dominant factor in defining the phase fields of the diagrams and a tentative model is proposed.
Get full access to this article
View all access options for this article.
References
1.
SellarsC. M. and MaakF., Trans. Met. Soc. A.LM.E., 1966, 236, 457.
2.
SeigleL. L., CohenM., and AverbachB. L., Trans. Amer. Inst. Min. Met. Eng., 1952, 194, 1320.
3.
SeigleL. L., ibid., 1956, 206, 91.
4.
HansenM. and AnderkoK., “Constitution of Binary Alloys”, 2nd edn. 1958: New York and London (McGraw-Hill).
5.
AukrustE. and MuanA., Trans. Met. Soc. A.LM.E., 1964, 230, 378.
6.
SteeleB. C. H., Ph.D. Thesis, Univ. London, 1965.
7.
DarkenL. S. and GurryR. W., J. Amer. Chem. Soc., 1945, 67, 1398.
8.
FischerW. A. and HoffmannA., Arch. Eisenhiittenwesen, 1957, 28, 771.
9.
AlcockC. B. and ZadorS., Electrochim. Acta, in the press.
