The diffusivity of oxygen in liquid copper-lead alloys

The oxygen diffusivity in liquid copper-lead alloys at 1403 K (1130‡C) was measured us-ing the electrochemical cell: Ni-NiOJZrO₂(+CaO)/O in liquid Cu-Pb alloy(I)/ZrO₂(+CaO)/O in liquid Cu-Pb alloy(II). Oxygen in liquid Cu-Pb alloy(I) was transferred to the right by applying a preselected voltage between the two liquid Cu-Pb alloys. The oxygen diffusivity in liquid Cu-Pb alloy(I) was calculated from the emf change with time between the Ni-NiO and liquid Cu-Pb alloy (I) electrodes. The results were: D_o (in pure Cu) = 8.14 (^+0.70 _-0.43) × 10⁵ cm²/s, D_o (in Cu-25 at. pct Pb) = 11.4(^+0.4 _-0.6) × 10^-5 cm²/s, D_o (in Cu-50 at. pct Pb) = 12.9(^+1.9 _-1.5) × 10^-5 cm²/s, D_o (in Cu-75 at. pct Pb) = 11.0(^+2.4 _-1.2) x 10^-5 cm²/s, D_o (in pure Pb) = 26.3(^+4.8 _-3.7) × 10^-5 cm²/s. It was found that the oxygen diffusivity in liquid copper-lead alloys did not change dras-tically over the entire composition range, in contrast with that reported by other investi-gators for liquid copper-nickel alloys. The oxygen diffusivity in pure liquid lead agreed with the results of our previous work using an FeO-Fe₃O₄ mixture as a sink for oxygen.