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

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

In order to develop an oxygen sensor using high temperature oxide film of zirconium alloy as a solid electrolyte, an alloy of zirconium with nickel was investigated to suppress the growth rate of zirconia oxide film on the alloy. In this study, the high temperature oxidation behavior of zirconium-nickel alloy was evaluated. The alloy was oxidized at 873 K in a mixture of argon and 1% oxygen. The relationship between the difference in oxidation rate and in the properties of the oxide film were compared and discussed with the cross-sectional images of the oxide film. The oxidation rate was the same or slightly higher than that of pure zirconium. In addition, the oxide film became thicker and voids were formed in some areas, and some cracks were also observed. The results did not show any tendency to reduce the activity of zirconium in the alloy and to decrease the oxidation rate.