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The layer-wise deposition intrinsic to extrusion-based additive manufacturing induces mesostructural features that behave as distributed air gaps and can modify the effective magnetic response of printed cores, an aspect that remains insufficiently documented for soft ferrites. In this work, the inherent impact of Fused Deposition Modeling (FDM) printing paths on the magnetic properties of additively manufactured MnZn ferrite cores is investigated experimentally. Toroidal cores were fabricated using a PIM-like FDM process from a polymer-based pellet feedstock loaded with 50 vol% MnZn ferrite powder. Two deposition routes were compared: concentric and rectilinear patterns. Magnetic characterization reveals a clear influence of the deposition path on the effective magnetic permeability. While moderate differences are observed under low-signal excitation, significant deviations appear at higher excitation levels. These variations are attributed to the oriented inter-bead porosities induced by the FDM process, which behave as distributed air gaps within the magnetic circuit. Additional investigations based on under-extrusion highlight a marked difference in sensitivity between the two deposition strategies, with concentric patterns exhibiting a higher robustness to local variations in material deposition. In contrast, magnetic losses remain only slightly affected by the deposition strategy. These results highlight the deposition path as an additional design parameter for tailoring the magnetic behavior of additively manufactured ferrite components.

Nickel–zinc (Ni–Zn) ferrites are widely used in the fabrication of high-frequency inductors operating above 1 MHz, particularly for filtering applications in power electronics. Ferrite manufacturers can benefit from advancements in additive manufacturing (AM), enabling the production of customised ferrite cores with complex geometries. In this work, an innovating AM process of Ni–Zn ferrites has been set up through a fused filament fabrication (FFF) printing stage from ferrite powder synthesis to sintered component. This proof of concept has been validated by a two-factor sintering design of experiments (temperature, time) and through bulk, microstructural and magnetic characterisations. The results indicate that the proposed process has the potential to achieve densifications of approximately 90% and real permeability values (μ′) in the range of 80 to 130, indicating performance levels comparable to those of conventional manufacturing techniques. The capabilities of the proposed process have been demonstrated by the printing of a ferrite-based 3D Benchy benchmark, highlighting its suitability for advanced component design in power electronics.

Additive manufacturing provides flexibility in terms of the shapes that can be produced. This work investigates the impact of Fused Deposition Modeling (FDM) printing paths on the magnetic properties of additively manufactured MnZn ferrite cores. Cores with concentric and straight deposition paths were manufactured using a 50%vol MnZn-filled filament. Magnetic characterization has revealed a significant difference in their static permeability. The process induced small air gaps in-between each deposition line, which influences significantly the permeability. This finding can be relevant for power electronics applications for distributed air gaps components.