Additive Manufacturing of Ferromagnetic Components by Inkjet Printing Followed by Sintering

Abstract

This study explores three different additive manufacturing processes using Fe6.5Si: Solvent on Granules 3D Printing (SG-3DP), Binder Jetting (BJT), and Laser Powder Bed Fusion (LPBF). Their ability to produce dense parts with optimized magnetic properties was compared. Two different Fe6.5Si powders were used during this project. One was sourced from Hoganas, while the other was sourced from HLPowder. Both powders were characterized in terms of density and flowability.

Parts printed with SG-3DP achieved positive results as their density averaged of around 95%. Cubes and shells were printed and the shells resulted in a stronger <001> crystallographic texture compared to that of the cube, which is beneficial for magnetic applications. Multiple parameters printing parameters were tested with LPBF printing before obtaining parts that yielded an average density of around 99% and were less prone to cracks. Crystallographic orientations varied depending on the part, with the reference cubes exhibiting a more dominant <111> texture, while the Hilbert cross-sectional parts exhibited a more dominant <101> texture.

Magnetic testing of toroidal parts fabricated with the SG-3DP and LPBF showcased the same magnetic saturation of 1.5T. However, the LPBF toroid performed better than the SG-3DP toroid in terms of permeability (164), coercivity (346 A/m), and in terms of power losses (12.7 W/kg).