Spark Plasma Sintering of Soft magnetic Materials

Over the past 3 decades, iron-based soft magnetic alloys such as Finemet (Fe73.5Si13.5B9Nb3Cu1 (at%)) have attracted great interest due to their exceptional magnetic properties like high magnetization, low coercivity, and high curie temperature. However, the production of amorphous precursor requires very high cooling rates, and thus only wires, powders, and thin ribbons are achievable, yet these are not suitable in industrial applications where large volume of bulk magnetic components is required. Mechanical alloying (MA) has gained special attention as a powerful non-equilibrium process for fabricating amorphous and nanocrystalline materials, whereas spark plasma sintering (SPS) is a unique technique for processing dense and near net shape bulk amorphous-nanocrystalline alloys with homogenous microstructure. The iron-based soft magnetic alloys have been fabricated by spark plasma sintering (SPS) process coupled with high energy ball milling. All the alloys have been processed from a mechanically alloyed blend of elemental powders, and their microstructures, microhardness, and phase formation are discussed. In addition, influence of ball milling parameters on microstructure and phase formation of these alloys have been investigated. This study will open new avenues for the development of soft magnetic materials, with complex shapes and excellent soft magnetic properties.