Lessons learnt - additive manufacturing of iron cobalt based soft magnetic materials

Additive manufacturing (AM) technologies have opened up new possibilities for realizing magnetic circuit designs, ultimately leading to electrical machines with enhanced performance, lower material consumption and cost. This study introduces lessons learnt of laser powder bed fusion (l-PBF) manufacturing of optimized soft magnetic cores. Processing routes from powder production of soft magnetic Fe-35Co, Fe-50Co, and Fe-49Co-2 V(Nb) materials, followed by process parameter optimization for l-PBF and finally the effect of heat treatment on the magnetic properties are shown. The major challenge is the mitigation of the eddy current losses. Effect of material composition as well as structural choices on the core losses of soft magnetic components are studied. Based on the magnetic measurements, the best heat treatment cycle led to magnetic saturation, permeability and coercivity comparable to commercial standardized Fe-49Co-2 V alloy. Magnetic measurement results of structurally modified test samples show that eddy current losses can be significantly reduced.