A microstructural study of mechanical alloying of Fe and Sn powders

Elemental Fe and Sn powders in the ratio of 1:2 were ball-milled for various times at room temperature, and phase transformations in the powders were studied by ⁵⁷Fe and ¹¹⁹Sn Mössbauer spectrometries, transmission electron microscopy, and x-ray diffractometry. Although Fe-Sn alloys are not obvious candidates for solid-state amorphization reactions, an amorphous phase formed after only a few hours of ball milling. Nanocrystalline intermetallic FeSn₂ particles nucleated and grew within the amorphous phase, and FeSn₂ became the major phase after 10–20 h of ball milling. These small particles were superparamagnetic, and were above the blocking temperature at room temperature.