Cu-Y-M(M=Sn、Zn、Pb)溶液体系的热力学性质

THERMODYNAMICS OF Cu Y M (M=Sn, Zn, Pb)LIQUID SOLUTIONS

利用ＣＣＯ控制反应２［Ｙ］＋３ＣＯ＝Ｙ２Ｏ３＋３Ｃ的平衡氧位，使多孔石墨坩埚中［Ｙ］达到等活度的原理，结合解病态方程组的共轭斜量法，求解出１２００℃铜液中Ｙ与Ｓｎ、Ｚｎ、Ｐｂ的活度相互作用系数，得到了反应２［Ｏ］＋２［Ｙ］＝Ｙ２Ｏ３的平衡常数Ｋ＝３．３×１０１９，铜液中Ｙ２Ｏ３的吉氏标准反应自由能为－５５０．５３ｋＪ／ｍｏｌ。

The isoactivity of of samples was obtained in multiple hole graphite crucibles by controlling the oxygen potential through the reaction 2+3CO=Y 2O 3+3C. The activity interaction coefficients between Y and Sn, Zn, Pb alloying elements were determined as follows by using conjugate gradient method of solving ill conditioned equations: for the Cu Y Sn sysytem, e Sn Y=1.544, γ Sn Y=-0.280, γ Sn, Y Y=-1.005, e Y Sn =2.060, γ Y Sn =-1.528, ε Y Sn = ε Sn Y=662.5; for the Cu Y Zn system, e Zn Y=0.062, γ Zn Y=-0.445, γ Zn, Y Y=0.169, e Y Zn =0.047, γ Y Zn =0.142, ε Zn Y= ε Y Zn =14.7, for the Cu Y Pb system, e Pb Y=-0.183, γ Pb Y=-0.100, γ Pb, Y Y=0.119, e Y Pb =-0.432, γ Y Pb =0.315, ε Y Pb = ε Pb Y= -139.5, the equilibrium products for Cu Y M (M=Sn, Zn, Pb)systems were identified as Y 2O 3 at 1 200 ℃. The equilibrium constant of reaction 3+2=Y 2O 3 is 3.3×10 19 , the standard free energy of formation of Y 2O 3 in liquid Cu is -550.53 kJ/mol.