several motor designs,” he said.
In some cases, the magnets produced via the additive manufacturing process resulted in magnets of better quality than those produced by injection molding.
“Through the additive process, magnet polymer composite pellets are melted and forced through a nozzle,” Paranthaman explained. “During this process, some degree of magnet particle aligning is possible. Also, in the injection process, the material spends a longer time in the IM machine barrel, where it is subject to mechanical friction and stresses, which would degrade the magnetic properties.”
The researchers chose nylon as a binder for the 3D-printed magnets, as it’s widely used in commercial injection-molded magnets.
“Nylon flows well during printing,” Paranthaman said. “We used nylon so we can compare the BAAM magnets with readily available nylon bonded injection magnets.”
Going forward, the research team plans to experiment with different binders and processing temperatures and hopes to speed up the process, which could eventually be refined to print at a rate of one meter/second. The team also plans to experiment with creating sintered magnets using additive manufacturing processes, and will attempt to print anisotropic, or directional, bonded magnets, and apply these magnets in motors.
“In-situ alignment is the biggest challenge for printing anisotropic magnets,” said Paranthaman. “Aligning the particles during printing while maintaining the shape of the magnet is challenging.”
The results of the ORNL team’s research was published in the journal, Scientific Reports. Funding for the project was provided by the DOE’s Critical Materials Institute (CMI).
Tracey Schelmetic graduated from Fairfield University in Fairfield, Conn. and began her long career as a technology and science writer and editor at Appleton & Lange, the now-defunct medical publishing arm of Simon & Schuster. Later, as the editorial director of telecom trade journal Customer Interaction Solutions (today Customer magazine) she became a well-recognized voice in the contact center industry. Today, she is a freelance writer specializing in manufacturing and technology, telecommunications, and enterprise software.