2002 Volume 42 Issue 7 Pages 679-684
For thermodynamic prediction, the deoxidation equilibrium of aluminum in Fe-36%Ni alloy was investigated by employing a cold crucible under an Ar gas atmosphere at 1 773 K. The interaction parameters between aluminum and oxygen by taking liquid Fe-36%Ni alloy as the basis (i.e., solvent) are evaluated as follows:
eOAl = -3.8, rOAl = -0.9, eAlO = -6.4, rAlO = 700, rAlAl, O = 3.1, rOAl, O = 833
within the composition range of [Al]<1 mass%.
The equilibrium constant for reaction 2Al(in Fe-36%Ni)+3O(in Fe-36%Ni) = Al2O3(s) was obtained in the temperature range of 1773 to 1973 K by using data from the present study and from previous works reported:
log KAO = 0.58−24460/T
The deoxidation equilibrium of aluminum in Fe-36%Ni can thus be thermodynamically described in the range of [Al]<1 mass% using both the first and second order interaction parameters as well as the equilibrium constant determined in this study.