Fe–Nb polycrystalline powders with a nominal composition of Fe \(_{0.95}\) Nb \(_{0.05}\) were synthesized via mechanical alloying (MA) and investigated for their high-temperature oxidation resistance. Structural and compositional analyses were performed using X-ray diffraction (XRD) and transmission Mössbauer spectroscopy (TMS). The results indicate that the actual Nb content incorporated into the bcc Fe matrix is significantly lower than the nominal value, with a maximum of approximately 2.4 at.% achieved after 50 hours of milling. Oxidation experiments conducted at 870 K in air revealed that Nb addition has a negligible effect on the oxidation resistance of the Fe matrix. The formation of Nb-rich surface layers, hypothesized to enhance corrosion resistance, was not observed. Instead, Nb atoms likely agglomerate within the matrix, forming clusters that do not contribute to improved oxidation behavior. These findings suggest that Nb is not an effective dopant for enhancing the high-temperature oxidation resistance of Fe-based powders prepared by mechanical alloying.
