Equilibrium of Mg-O and the Effect of Fe,Al and Cr on the Activity of Mg in Molten Nickel

The equilibrium constant of Mg-O in Nickel melt at the temperature range of 1 480℃ to 1580℃ was determined with the vapour equilibrium method in a sealed chamber. The influence of the alloying elements Fe, Al and Cr on the activity of Mg in nickel melts at 1480℃ mas investigated. It was found that at 1480℃ to 1580℃: $\log {K_{{\rm{MgO}}}} = 0.50 + 1.27 \times {10^4}/T;G_{{\rm{MgO}}}^{\rm{o}} = 2.43 \times {10^5} - 9.57T({\rm{J/mol}});e_{\rm{Mg}}^{{\rm{O}}} = 1.10 \times {10^3} - 2.19 \times {10^6}/T$; And at 1480℃: $e_{{\rm{Mg}}}^{{\rm{Fe}}} = - 0.28;e_{{\rm{Mg}}}^{{\rm{Al}}} = - 0.51;e_{{\rm{Mg}}}^{{\rm{Cr}}} = 0.72$