Researchers at the Department of Energy’s Oak Ridge National Laboratory have recently demonstrated that permanent magnets produced by additive manufacturing can outperform bonded magnets made using traditional techniques while conserving critical materials.
Scientists fabricated isotropic, near-net-shape, neodymium-iron-boron (NdFeB) bonded magnets at DOE’s Manufacturing Demonstration Facility at ORNL using the Big Area Additive Manufacturing (BAAM) machine. The additive manufacturing process began with composite pellets consisting of 65 volume percent isotropic NdFeB powder and 35 percent polyamide (Nylon-12) manufactured by Magnet Applications, Inc. The pellets were melted, compounded, and extruded layer-by-layer by BAAM into desired forms.
“Manufacturing is changing rapidly, and a customer may need 50 different designs for the magnets they want to use,” said ORNL researcher and co-author Ling Li. Traditional injection molding would require the expense of creating a new mold and tooling for each, but with additive manufacturing the forms can be crafted simply and quickly using computer-assisted design, she explained.
Future work will explore the printing of anisotropic, or directional, bonded magnets, which are stronger than isotropic magnets that have no preferred magnetization direction. “This work has demonstrated the potential of additive manufacturing to be applied to the fabrication of a wide range of magnetic materials and assemblies,” said co-author John Ormerod. “Magnet Applications and many of our customers are excited to explore the commercial impact of this technology in the near future,” he stated.