A mass-spectrometric study of the thermodynamics of the Fe−Cu and Fe−Cu−C(sat) systems at 1600°C

Autor: Choudary, U., Serkin, J., Belton, G.
Zdroj: Metallurgical and Materials Transactions B; September 1975, Vol. 6 Issue: 3 p399-403, 5p
Abstrakt: Abstract: The Knudsen cell-mass spectrometer combination has been used to study the Fe−Cu and Fe−Cu−C(sat) alloys at 1600°C. Activity coefficients in the Fe−Cu system are closely represented by the equations
$$\begin{gathered} \ln \gamma _{Fe} = 1.86N_{Cu}^2 + 0.03, (0< N_{Fe}< 0.7) \hfill \\ \ln \gamma _{Cu} = 2.25N_{Fe}^2 - 0.19, (0.7< N_{Fe}< 1.0) \hfill \\ \end{gathered} $$
with an uncertainty in the quadratic terms of about 5 pct. For the iron-rich carbon-saturated alloys, the activity coefficient of copper is given by the equation
$$\ln \gamma _{Cu} = 2.45(N'_{Fe} )^2 + 0.3N'_{Fe} + 0.03, (0< N'$$
to within an uncertainty of about 10 pct. N Fe′ represents the fraction NFe/(NFe+NCu), etc. The activity coefficient of iron in this region is found to be essentially constant at 0.69±0.05.
Databáze: Supplemental Index
Externí odkaz: