High temperature oxidation of Zr-36 at.%Ni alloy at 873 K

Ohigashi, Jun*; Ueda, Mitsutoshi*; Kawamura, Kenichi*; Irisawa, Eriko ; Komatsu, Atsushi ; Kato, Chiaki   

As a development of oxygen sensors using high-temperature oxide layer of zirconium alloys as solid electrolytes, an alloy of zirconium with nickel was investigated to control the growth rate of zirconia oxide layer on the alloy. In this study, the oxidation behavior of zirconium-nickel alloys at high-temperatures was evaluated. As a result, it was found that when the oxygen potential in the gas atmosphere was decreased, the oxidation rate increased significantly, completely different from the case of pure zirconium. In the case of zirconium-nickel alloys, it was considered that this is because the electronic conduction in the oxide film is large due to the presence of metallic Ni in the oxide film, and oxygen ion conduction is the rate-limiting factor even in an atmosphere with a low oxygen partial pressure.