Five ternary alloys consisting of a noble base metal (Ni, Co, Fe, Cu) and two reactive metals (Zr + Y, Ce + Gd) being able to form a high oxygen ion conductive oxide were internally oxidized under low oxygen partial pressures. All alloys developed either a continuous yttria-stabilized zirconia phase or a continuous gadolinia-doped ceria phase behind the front of internal oxidation. A Ni–Ce–Gd alloy showed extraordinarily high internal oxidation rates of up to 120 µm2/s at 900 °C. High internal oxidation rates in these ternary alloys were not limited to low concentrations of the reactive metals. The type of the internal oxide phase was found to be more important for the internal oxidation kinetics than the noble base metal.
Internal oxidation Diffusion YSZ GDC
The financial support from the Deutsche Forschungsgemeinschaft (DFG) within the project GL 181/32-1 is gratefully acknowledged.
C. Wagner, Zeitschrift für Elektrochemie63(7), 772 (1959) .Google Scholar