Defect structure of Fe-AL and Fe-Al-Ni metallic powders obtained by the self-decomposition method and intensive grinding in the electro-magneto-mechanical mill

Abstract

The Fe-Al and Fe-Al-Ni metallic powders produced by the self-decomposition method and then intensive grinding in an electro-magneto-mechanical mill with Fe and Ni additions were examined by X-ray powder diffraction, scanning electron microscopy and Mössbauer spectroscopy. The concentration of vacancies and Fe atoms occupying Al positions (Fe-AS atoms) was determined from the Mössbauer spectra analysis connected with distinct Fe environments. The results show that nickel addition causes both an increase in vacancy concentrations in comparison with values found for Fe-Al metallic powders and a significant increase in the antisite Fe-AS atoms concentration. Intensive highenergy grinding in the electro-magneto-mechanical mill modifies the phase composition of the studied materials and changes the concentration of point defects.