Exploring the Soft Magnetic Properties of Various Iron–Silicon Alloys Manufactured via SLM

This study investigates the printability and soft magnetic performance of three iron-silicon-based alloys—Fe-6.5Si, Fe-9Si-6Al (Sendust), and Fe-6.5Si-0.1B—fabricated via selective laser melting (SLM). The effect of volumetric energy density (VED) on structural integrity and magnetic properties was systematically examined. The results demonstrate that Fe-6.5Si toroidal cores can be successfully manufactured across a relatively broad process window, with optimal magnetic performance obtained at moderate energy inputs. Sendust alloys exhibited the lowest hysteresis losses within the investigated range (Bmax= 0.2 T), while the FeSiB alloys suffered from poor structural integrity and elevated porosity, likely caused by boron-related intergranular precipitation. Reproducibility tests performed on Fe-6.5Si confirmed a coercivity error margin of approximately 3%, which can be considered acceptable given the complexity of the process and sample geometry. Overall, the findings highlight both the potential and the current challenges of using SLM for advanced soft magnetic applications, underscoring the need for tailored scanning strategies to reduce structural defects and enhance repeatability.