Additive manufacturing of soft magnetic materials and components

Additive manufacturing of soft magnetic materials and components based on laser powder bed fusion (L-PBF) offers new opportunities for soft magnetic core materials in efficient energy converters. For more favorable material compositions like FeSi6.7 (strategy 1) with larger electrical resistivity and close-to-zero magnetostriction a maximum permeability of mu(max) = 31,000, minimum coercivity of H-c = 16 A/m and hysteresis losses of 0.7 W/kg at 1 T and 50 Hz have been realized. To further reduce eddy current losses significantly, novel topological structures like inner slits (strategy 2) and multilayered structures of alternating layers of electrically insulating material and soft magnetic material (strategy 3) are suggested. Feasibility, functionality and potential of the different strategies (and combinations thereof) are discussed based on first prototypes and supporting simulations. The results are compared to conventional electrical steel and SMC (soft magnetic composites).