Oxidation processes for alloys in the Ni-Zr system.: I.: Structure of Ni-Zr 14 alloys.: Oxidation kinetics for Ni7Zr2

We have studied the synthesis conditions and crystal structures for one-phase intermetallic alloys Ni5Zr, Ni7Zr2, and NiZr. We used the continuous weighing method to study the oxidation kinetics in air for the alloy Ni7Zr2 in the range 500-1000degreesC. We have shown that the oxidation process is described mainly by a parabolic law. The kinetic isotherms for the change in mass suggest that over time, the rate constant for parabolic oxidation K-p decreases due to improvement in the protective properties of the scale. The temperature dependence of the oxidation rate suggests a change in the oxidation mechanism for T>800degreesC, due to changes in the defect structure of the ZrO2 lattice.