Design of Insulation Layer Structures in 3-Dimensional Fe-6.5%Si Cores via Dual-nozzle Material Extrusion combined with Spark Plasma Sintering technology
Description
We present a novel hybrid manufacturing approach that combines dual-nozzle material extrusion and spark plasma sintering to fabricate metal–insulator–metal-structured Fe-6.5 wt.% Si (Fe-6.5Si) magnetic cores. This process integrates MgO-B2O3-SiO2 (MBS) insulation layers to achieve enhanced bonding between the layers. The manufacturing process involved integrating MBS insulation for structural integrity, reducing the Fe-6.5Si layer thickness for frequency stability, and applying a post-heat treatment to improve magnetic performance. The MBS insulation system demonstrated sinterability, forming stable interfaces with the Fe-6.5Si layers. Through experimental investigation, we found that a Fe-6.5Si layer thickness of 0.6 mm combined with 0.2-mm MBS insulation layers exhibited promising frequency stability up to 1 kHz. Additionally, post-heat treatment at 1200 °C enhances the magnetic properties by increasing the permeability and reducing hysteresis loss through grain growth and interface modification. This manufacturing approach has the potential to produce high-performance magnetic cores while offering design possibilities for fabricating various part geometries compared with conventional methods.
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Steps to reproduce
- Gas-atomized Fe-6.5Si powder (MK Co., Ltd., Republic of Korea) served as the primary soft magnetic material, with particles sieved to a maximum size of 75 µm and an average size of 25 ± 20 µm, as shown in Figure 3(a). The insulation material comprised MgO (40 wt.%) (Hanaro TR Co., Ltd., Republic of korea), B2O3 (5 at.%) (Duksan pure chemicals Co., Ltd. Republic of Korea), and SiO2 (55 at. %) (Avention Co.,Ltd., Republic of Korea) particles - The printing process was performed using a D-MEX printer (Reprotech, Inc.). - The printed green parts were then densified using SPS (JP/SPS-1030; Welltech, Republic of Korea). The SPS parameters included a sintering temperature of 1000 °C, a 10-min holding time, and an applied pressure of 25 MPa at a heating rate of 100 °C /min. - The magnetic characteristics were evaluated using a B–H analyzer (SY-8219, Iwatsu) with a saturation magnetic flux density of 10 kA/m. Core losses were measured at a fixed magnetic flux density of 1 T across frequencies ranging from 50 Hz to 1 kHz. For B–H analysis, the effective magnetic dimensions were calculated from R_OD, R_ID, and h of the toroidal core.
Institutions
- Hanyang University
- Hanyang University - Ansan Campus