Abstract
The oxidation stability of acicular Fe-Co particles in the high temperature range has been investigated using the thermogravimetry method. The rate of oxidation reaction decreases with the increase of Co content in metal particles. From the analysis of the oxidation process, the reaction mechanism of Fe-Co particles can be explained by an unreacted core model with a rate controlling process of diffusion in a continuous product layer. The oxide from the iron particle at 573 K is γ-Fe2O3, while the oxide from the Fe-Co particle is Fe3O4 or CoFe2O4 and the production of γ-Fe2O3 is suppressed. Therefore it is found that the oxidation stability in the high temperature range is improved by the addition of cobalt in metal particles.
