New 3D Printing Process Creates Magnets with No Rare Earth Waste, Greater Design Flexibility

R&D 100 Staff
May 23, 2018, 3:24 p.m.

A new 3D printing method to produce permanent magnets, may result in substantially less wasted materials, while giving manufacturers far more design shape and size options.

Using a process called Big Area Additive Manufacturing (BAAM), researchers from the Oak Ridge National Laboratory (ORNL) have fabricated isotropic, near-net-shape, neodymium-iron-boron (NdFeB) bonded magnets with no size or shape limitations, no rare earth waste, no tooling costs and less energy consumed. BAAM fabricates isotropic near-net-shape NdFeB bonded magnets with comparable or better magnetic, mechanical and microstructural properties than bonded magnets, using traditional injection molding with the same composition.

The innovation—which was a 2017 R&D 100 Award winner—was designed to conserve material, which is especially important in the manufacturing of permanent magnets made with neodymium and dysprosium—rare earth elements that are mined and separated outside the U.S., said Parans Paranthaman, principal investigator and a group leader in ORNL’s Chemical Sciences Division.

“The yield [cutting from sintered blocks to various size and shaped sintered magnets] can be as low as 52 percent, so we start with the expensive, rare magnets and by the time you make the final product size you are losing some of this material,” Paranthaman said in an interview with R&D Magazine. “We were looking for a process where the yield can be quite high.

“What we have done is we used polymers as a binder and used this 3D printing technique where the yield can be close to 100 percent,” he added. “These are thermoplastic polymers, meaning you can always re-melt and reuse it, and that is why the yield is quite high.”

The new magnets are produced with composite pellets consisting of a 65 volume percent isotropic NdFeB powder and 35 percent polyamide (Nylon-12). The pellets are then melted, compounded and extruded layer-by-layer by BAAM into the desired forms.

Bonded magnetics are usually fabricated by blending magnetic powders with a polymer that acts as a binder. The mixture is then molded into the desired shapes and sizes by utilizing one of several popular commercial processing methods, including injection molding, compression molding, extrusion and calendaring.

However, the new system can deposit high-performance engineered thermoplastics and customized thermoplastic composites through melt extrusion processing. This processing enables the rapid manufacturing of parts completely unbounded in size. Instead of requiring the pre-extruded filament feedstock commonly used in standard industrial extrusion-based systems, BAAM combines melting, compounding, and extruding functions to deposit polymer product at a controlled rate.

“We can make several different designs and parts compared to injection molding,” Paranthaman said. “We have taken these magnets and demonstrated in a small DC motor and showed performances almost comparable.”

Tensile tests performed on four dog-bone shaped specimens yielded an average ultimate tensile strength of 6.60 MPa and an average fail strain of 4.18 percent.

NdFeB, which are the most powerful magnets on Earth, are used in computer hard drives, headphones, and clean energy technologies such as electric vehicles and wind turbines.

The researchers have applied for a patent on the new technology. Parathaman also said that the group has licensed the new technology to Momentum Technology, a Dallas-based firm that hopes to commercialize the process in the next three to five years.  

Apply for the 2018 R&D 100 Awards

Additively Printed High Performance Magnets, from Oak Ridge National Laboratory (ORNL), was a 2017 R&D 100 Award winner. The winners were announced at The R&D 100 Awards Gala held in Orlando, Florida on Nov. 17, 2017. See the full list of 2017 R&D 100 Award Winners here.

The R&D 100 Awards have served as the most prestigious innovation awards program for the past 56 years, honoring R&D pioneers and their revolutionary ideas in science and technology.

Submissions for the 2018 R&D 100 Awards are now being accepted. Any new technical product or process that was first available for purchase or licensing between January 1, 2017 and March 31, 2018, is eligible for entry in the 2018 awards. Entries for the R&D 100 Awards can be entered under five general product categories— Mechanical Devices/ Materials, IT/Electrical, Analytical/Test, Process/Prototyping, and Software/Services.

The deadline is June 1, 2018.

To apply visit: