Fabrication of Multifunctional FeSi Gyroid Lattice Composites via Additive Manufacturing and Polymer Infiltration

This study presents a novel two‐step manufacturing approach for fabricating multifunctional metal–polymer lattice composites by combining laser powder bed fusion (LPBF) of FeSi2.9 electrical steel with pressure infiltration of Bakelite polymer. Gyroid lattice structures with varying cell sizes and solidity levels are successfully printed, achieving high relative densities under optimized parameters. Bakelite infiltration fully occupies the internal voids, forming robust composites with enhanced mechanical stability. Compression testing reveals that infiltrated lattices exhibits yield strengths (273.7 ± 1.03 MPa), surpassing those of dense samples (253.64 ± 4.52 MPa), while maintaining structural integrity up to 60% engineering strain without fracture. Magnetic characterization reveals that Bakelite infiltration does not significantly alter the intrinsic soft magnetic properties of FeSi2.9, despite the pronounced magnetic anisotropy observed, which is driven by the crystallographic texture developed during LPBF processing. These results demonstrate a promising strategy for creating lightweight multifunctional composites with combined structural and functional properties.