Oxidation Processes for Alloys in the Ni – Zr System. Part 1. Structure of Ni – Zr 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 500-1000°C. 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 > 800°C, due to changes in the defect structure of the ZrO₂ lattice.