THERMODYNAMICS OF Cu-Y-M(M=Al,Si,Ti,Fe)LIQUID SOLUTIONS
(Central Iron and Steel Research Institute; Beijing 100081)
Abstract: The iso-activity of [Y] of samples reached in multiple-hole-graphite crucibles by controlling the oxygen potential through the reaction 2[Y]＋3CO=Y2O3＋3C. Combining conjugate gradient method of solving ill-conditioned equations, the activity interaction coefficients betweer Y and Al, Si, Ti, Fe alloying elements were determined. The equilibrium constant of the reaction Z[Y]＋3[O]=Y2O3 and the standard free energy of formation of Y2O3 in liquid Cu were obtained at 1200℃.
Key words: iso-activity interaction coefficient; Cu-Y-M(M=Al; Si; Ti; Fe)