Microstructure and soft magnetic behavior of FeSiAl soft magnetic alloys fabricated via selective laser melting

FeSiAl magnetic cores are extensively utilized in power electronic devices. Additive manufacturing techniques, particularly selective laser melting (SLM), are increasingly employed to fabricate magnetic cores, meeting the demands for miniaturization and integration of electronic systems. This study fabricated FeSiAl magnetic cores via SLM, with varying line laser energy densities (LED). The correlation between LED and microstructure was examined from the perspective of rapid solidification. Grain morphology was dominated by equiaxed crystals in the cross-sectional plane (x-y) and columnar crystals in the longitudinal planes (x-z and y-z). Notably, the printed samples exhibit alternating coarse and fine grain zones, with Si element enrichment observed at melt pool boundaries. Increasing LED reduces defects and promotes larger grain growth, with the strongest texture (7.64) along the building direction (BD) observed at an LED of 167J/m. For the sample processed at LED = 167J/m, a saturation magnetization of Ms = 124.3emu/g, coercivity of Hc = 2.9Oe (magnetic field // BD), relative permeability μ = 51.6 (f = 100kHz), and power loss Pcv = 728.39mW/cm3 (Bm = 20 mT, f = 100kHz) were achieved.