New 3D Printed Magnets Outperform Sintered VersionsNew 3D Printed Magnets Outperform Sintered Versions

Researchers at the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) recently published research showing that permanent magnets made with additive manufacturing techniques, or 3D printing, can outperform traditional bonded magnets produced by injection molding, the federal research center announced Tuesday.

The research, published in Scientific Reports, outlines a new type of isotrophic, near-net-shape, neodymium-iron-baron (NdFeB) magnet produced with the ORNL’s Big Area Additive Manufacturing (BAAM) machine. By 3D printing the magnets instead of bonding them together, researchers hope to reduce the amount of critical materials used in the production of magnets.

Researchers said the 3D printed magnet “was a product with comparable or better magnetic, mechanical, and microstructural properties than bonded magnets made using traditional injection molding with the same comparison.”

Using composite pellets made with isotropic NdFeB powder and polyamide (Nylon-12) produced by Magnet Applications Inc., the DOE’s researchers used the BAAM machine to melt, compound, and extrude layers into the magnet forms. The material waste from traditional sintered magnet manufacturing is as much as 30% to 50%, according to Parans Paranthaman, principal investigator and the group leader of the laboratory’s Chemical Sciences Division, but magnets produced with additive manufacturing would result in zero waste.

Beyond conserving valuable materials, the researchers point out that 3D printing offers the flexibility to create magnets in a variety of shapes and sizes quickly and easily, without additional tooling.

“Manufacturing is changing rapidly, and a customer may need 50 different designs for the magnets they want to use,” said the study’s co-author, Ling Li, an ORNL researcher. Each design produced with injection molding requires its own mold and tooling, while commuter assisted design in 3D printing eliminates that expense and time, she said.

ORNL said future research will look at anisotropic bonded magnets, a form of magnet that has no preferred magnetization direction, the effect of binder type, loading fraction of magnetic powder, and the impacts of processing temperature on the magnetic and mechanical properties of the printed magnets.

“The ability to print high-strength magnets in complex shapes is a game changer for the design of efficient electric motors and generators,” said Alex King, director of the Critical Materials Institute, a sponsor of the research. “It removes many of the restrictions imposed by today’s manufacturing methods.”

For more information, view the DOE’s press release.

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