Nanocrystalline and Amorphous FeAlSn Alloy Prepared by Mechanical Alloying

Abstract

A nanostructured disordered FeAlSn solid solution of Fe–26% Al–2% Sn composition was obtained from elemental Fe, Al and Sn powders using a high-energy ball mill. X-ray diffraction and electron microscopy supported by Mössbauer spectroscopy techniques have been applied to follow changes in the microstructure, phase composition and magnetic properties in dependence on milling time. The transformation of the phase depends upon the milling time. With the increase of milling time all Al and Sn atoms dissolved in the bcc Fe and the final product of the MA process was the nanocrystalline Fe (Al, Sn) solid solution in a metastable state with large amount of defects and mean crystallite size of 5 nm. The electron microscope observations show morphology of powder particles and changes in chemical composition during mechanical treatment. The changes in composition are observed at samples formed by mechanical alloying. On the other hand the composition of Fe72Al26Sn2 pieces is influenced by milling. Magnetic properties of the nanocrystalline mechanically alloyed FeAlSn were also investigated and were related to the microstructural changes.