Fabrication of periodic axial air-gap structures using LPBF with wobble-based scanning for enhanced magnetic core components

Abstract This study investigates laser powder bed fusion with a wobble-based scanning strategy to form three-dimensional, periodically spaced axial air-gap structures for magnetic-core components. The material was Fe–79Ni–4Mo soft-magnetic powder (PC-Permalloy). A fixed-overlap WBS strategy with design parameters of swing width and hatch-distance (HD) ratio was used to evaluate the capability to generate periodic axial air gaps and to characterize the resulting holes and thin walls. Using large swing widths, multiple periodic axial air gaps were produced in a single scanning pass, with hole diameters of approximately 110 to 425 μm. By controlling the swing width and HD ratio, the air-gap lattice could be tailored to rectangular or circular patterns. Adjusting the WBS parameters also tuned the hole size in the magnetic-core air gaps, which in turn modified permeability and enabled control of both maximum magnetic flux and iron loss.