A Comparative Study of Nanostructured Fe and Equiatomic FeCo Magnetic Powders Produced by High Energy Milling

Mechanical alloying can be used in the preparation of various metal-metal systems, including the magnetic iron-cobalt powders applied in advanced transformers and magnetic bearings [1]. Fe-Co is a substitutional alloy with a body-centered cubic crystal structure over the concentration range 0-80 at.% Co; higher concentrations lead to a face-centered cubic structure [2].Pure iron is a good ferromagnetic material with a low resistivity so in some applications it leads to large eddy current losses. Alloying can be engineered to instill greater magnetic permeability and lower core losses [3]. Cobalt in iron is unique in increasing simultaneously the saturation magnetization and Curie temperature. Although the maximum saturation magnetization (MS) occurs at a concentration of 35 at.% Co, equiatomic compositions offer a considerably larger permeability for similar MS [4].In this work, Fe and Fe50Co50 nanocrystalline powders synthesized using mechanical alloying and the effects of milling time on the microstructural and magnetic properties investigated