Synthesis of nanocrystalline Fe-B-Si powders

Abstract

Abstract The synthesis of a nanocrystalline Fe-B-Si alloy by mechanical alloying in a SPEX mill is investigated. Electron probe microanalysis and precise lattice parameter measurements indicate that 64 hours of milling of elemental powders is insufficient to produce the complete dissolution of either Si or B in Fe. Additional milling to 128 hours results in dissolution of the majority of Si, but only partial dissolution of B. After 128 hours of milling, however, 38 wt.% of the composition consists of debris from vial and ball wear. Prolonged milling up to 256 hours does not result in increasing dissolution. In an effort to circumvent these difficulties, pre-alloyed Fe-B-Si powders were produced using spray atomization. Milling of these powders resulted in the precipitation of Fe 2 B. This precipitation process was essentially complete after 50 hours of milling, resulting in a nanocrystalline Fe(Si) solid solution with homogeneously distributed Fe 2 B precipitates.