2006 Volume 47 Issue 1 Pages 122-128
In order to obtain the solubility and activity of oxygen in Pb–Bi melts, the research for oxygen analysis and oxygen partial pressure measurement in a lead–bismuth eutectic alloy (LBE) was performed. The analytical condition of oxygen in low melting metals by an inert gas fusion-infrared absorption method was established using Pb or Bi equilibrated with its corresponding oxide at 973 K as a standard sample for the oxygen analysis. After establishing the analytical condition, oxygen analysis in liquid LBE in equilibrium with solid PbO at various temperatures was done. The temperature dependence of oxygen solubility in liquid LBE was expressed by the following equation, log(C_O/mass ppm)=-4.74×10^3/T+7.06(±0.03) (878≤T/K≤1073) Oxygen partial pressure in LBE–(PbO and/or PbO+Bi2O3) equilibrium was measured using an oxygen sensor of a zirconia solid electrolyte (ZrO2−Y2O3), and obtained as a function of temperature as 2 & log( p_O2/P^°)=10.96-2.259×10^4/T & & (720≤T/K≤1098)
& log( p_O2/P^°)=2.49-1.330×10^4/T & & (1098≤T/K≤1252) From the results, the oxygen potential in LBE at the oxygen unsaturated region was estimated as, RTln( p_O2/P^°)/(J/mol)=-58.59T-2.510×10^5+38.29Tlog(C_O/mass ppm) The activity coefficient of oxygen in liquid LBE obtained using Blander’s oxygen dissolution model was compared with these experimental data and those of other investigators.