Assessment of the compacting and annealing process steps on the performance of finished Soft Magnetic Composite components

Cores for electromagnetic applications made of Soft Magnetic Composite (SMC) materials consist of individually electrically insulated magnetic iron particles, processed by conventional powder metallurgy (PM) routes. The core loss characteristics of a finalized SMC component are related to the process treatments that it has been subjected to. In this context, the effect of uniaxial compaction and annealing steps has been assessed for different pressure and temperature regimes by means of electron backscatter diffraction (EBSD) and nano-indentation techniques. Deformation maps obtained with EBSD were coupled with nano-mechanical testing, denoting the degree of induced stresses and their relaxation in the cross sections of the parts. The development of the internal microstructure and extent of mechanical deformation under processing were also evaluated and correlated to the performance of the parts under question. The results reveal a more direct approach for determining the relationship between magnetic properties and processing treatment of SMC components.