Research on the texture and magnetic properties of Fe–6.5 wt. % Si alloy with slit structure manufactured by laser powder bed fusion (L-PBF)

The issue of high iron loss caused by excessive thickness in traditional laser additive manufacturing is addressed by introducing slit structures into Fe–6.5 wt. % Si alloy samples fabricated via selective laser melting processing. The influence of slit width (0.05–0.20 mm) and scanning parameters on microstructure, texture evolution, and magnetic performance is systematically examined. The results indicate that slit geometry and scanning velocity critically affect melt pool morphology and grain growth. At a higher 800 mm/s scanning velocity, the slit structure becomes more distinct, and as the slit width increases, columnar grains exhibit enhanced growth along the normal direction, accompanied by a strengthening of {001}⟨110⟩ (rotated cube) and {001}⟨100⟩ (cube) textures. Annealing at 1200 °C induces abnormal grain growth and the development of strong {331}⟨136⟩, {113}⟨392⟩, and {001}⟨190⟩ texture components. Notably, expanding the slit width to 0.20 mm markedly improves soft magnetic properties, achieving a coercivity of 20.19 A/m, a saturation magnetic induction of 1.12 T, a maximum relative permeability of 10.82 × 103, and a high-frequency iron loss P10/400 of 590.9 W/kg. This work establishes a structural-design strategy for performance control in additively manufactured soft magnetic materials, opening avenues for advanced high-frequency motor applications.