Topology optimized soft magnetic cores by laser powder bed fusion

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 laser powder bed fusion (L-PBF) manufacturing of topology optimized soft magnetic cores. As a first step of optimization, we investigate perforated core structures with gaps the purpose of which is to decrease the losses. Processing route starting from powder production of soft magnetic Fe-49Co-2V material, followed by process parameter optimization for L-PBF and finally the effect of heat treatment on the magnetic properties are shown. Effect of structural choices on the core losses of the soft magnetic components is studied. Based on the magnetic measurements, the best heat-treatment cycle led to magnetic saturation, permeability and coercivity comparable to commercial standardized Fe-49Co-2V alloy. Magnetic measurement results of perforated test samples show that eddy current losses can be significantly reduced with small structural modifications. Finite element computations performed support this conclusion.