Production of soft magnetic FeSi6.5 parts with precise layer topography using integrated laser remelting at PBF-LB/M to induce multi-material lamination

Abstract

Laser-based Powder Bed Fusion of metals (PBF-LB/M) additive manufacturing offers great potential for producing efficiency- and performance-enhancing soft magnets. Thereby, the layer-wise process enables fabrication of complex three-dimensional magnetic flux guiding geometries, insulating air gaps and multi-material laminated structures made of high-performance soft magnetic alloys with integrated insulating layers. In order to achieve thin insulating layers for the inhibition of eddy current losses in PBF-LB/M multi-material laminated structures, high-precision layer surface topographies with low surface roughness are required. In this research work, the implementation of single remelting on the top solidified PBF-LB/M layer surface and cyclic remelting during the PBF-LB/M build-up is investigated for FeSi6.5. It can be shown that the top layer surface roughness can be reduced by 38.3% by single remelting and can be further improved by cyclic remelting during PBF-LB/M build-up. Cyclic remelting also changes grain structure in the component volume, whereby grain growth can be observed.