The initial stage of mechanical alloying in Cr-Fe binary systems

The initial stage of mechanical alloying in Cr-Fe binary systems with atomic ratios of 80: 20 and 99: 1 (57Fe) has been studied by Auger spectroscopy, X-ray diffraction, and Mossbauer spectroscopy. Cr(Fe) x O y oxide clusters are formed at the sites of the contact between Cr and 57Fe particles at the earliest stages of mechanical treatment of the Cr(99)/57Fe(1) mixture. As the treatment duration is increased and a nanostructured state develops, oxide clusters are destroyed and O dissolves in the Cr matrix to increase the lattice parameter of Cr. As the nanostructure is formed in Cr, Fe atoms penetrate through the grain boundaries into the close-to-boundary distorted zones and then into the grain bulk. The process is characterized by a nonuniform concentration distribution of Fe atoms in Cr. The yield of reaction products and specific surface area of grain boundaries have been established to linearly depend on the mechanical energy dose at the initial stage of mechanical alloying.