Thermodynamics of the oxygen solutions in the aluminum-containing Ni–Co melts

A thermodynamic analysis of the oxygen solutions in the aluminum-containing Ni–Co melts has been performed. The equilibrium constants of reactions of aluminum deoxidation of nickel-cobalt melts, the activity coefficients at infinite dilution, and the interaction parameters for the melts differing in composition at 1873 K have been determined for the first time. The dependences of the oxygen solubility on the cobalt and aluminum contents in the melts are calculated. The deoxidizing capacity of aluminum slightly varies as the cobalt content in a melt increases to 20%; at higher cobalt contents in the melts, it increases substantially. The aluminum contents at the minima in the oxygen solubility curves and the oxygen contents corresponding to the aluminum contents have been determined. © 2017, Pleiades Publishing, Ltd.