Initial stage of mechanical alloying in a binary system with composition [Si.sub.70][Fe.sub.30]

Mossbauer spectroscopy and X-ray diffraction have been used to study the sequence of solid state reactions that occur upon the mechanical alloying of mixtures of Si and Fe powders taken in an atomic ratio of 70: 30 in a planetary ball mill. In the course of the formation of a nanocrystalline state, the interpenetration of Si atoms into Fe particles and of Fe atoms into Si particles occurs. In the Si particles, clusters with a local neighborhood of Fe atoms that is characteristic of the deformed α-Fe[Si.sub.2] phase are formed. In the Fe particles, clusters of the ζ-FeSi and the β-Fe[Si.sub.2] type arise. With increasing time of mechanical treatment, second phases of α-Fe[Si.sub.2] in Si particles and of ζ-FeSi and β-Fe[Si.sub.2] in Fe particle are formed. In the latter case, a reaction ζ-FeSi + Si → β-Fe[Si.sub.2] occurs up to the complete disappearance of the ζ-FeSi phase if the mixture under study is not contaminated by the material of the vessel (Fe) and balls. Keywords: silicon, iron, mechanical alloying, solid-state reactions, X-ray diffraction, Mossbauer spectroscopy DOI: 10.1134/S0031918X13110100