Abstract
Nickel‐cobalt alloys of high purity, in sheet form, were oxidized in air at temperatures ranging from 800° to 1400°C. The oxidation rate of high purity carbonyl nickel was found to be lower than previously reported in the literature. The oxidation rate increased with increasing cobalt content, but the effect was small until over 11% cobalt had been added. The activation energy for oxidation decreased with increasing cobalt content from a value of 51 kcal/mole for pure nickel to about 28.8 kcal/mole for pure cobalt.