The US Department of Energy’s Critical Materials Institute (CMI) has taken a major step toward printed, aligned anisotropic magnets via additive manufacturing processes. The Energy Innovation Hub manufactured hybrid nylon-bonded neodymium-iron-boron and samarium-iron-nitrogen magnets using the Big Area Additive Manufacturing (BAAM) located at Oak Ridge National Laboratory.
The research is discussed in a paper published in the Journal of Magnetism and Magnetic Materials.
Complex near net-shaped Nd2Fe14B (Nd-Fe-B) permanent magnets are desirable in numerous applications because they enable device miniaturization and weight reduction. Traditionally, bonded magnets are fabricated by either compression molding with a thermoset binder or injection molding with a thermoplastic binder. Also tooling dies used for conventional molding are expensive and capable of producing only a limited number of sizes and shapes. This challenge can be addressed by additive manufacturing techniques which recently have attracted great interest due to their advantages in printing complex shapes without any tooling and minimizing loss of critical materials.
… Hybrid magnetic composite bonded magnets have been explored recently for the improvement of dynamic mechanical, thermal and magnetic properties, as well as corrosion resistance.—Gandha et al.
The application of additive manufacturing to magnet production is relatively new, and there are challenges to overcome between the nature of the process and the end properties of the product, said Ikenna Nlebedim, a Oak Ridge scientist at the CMI and co-corresponding author of the paper.
A post-printing alignment process with applied electromagnetic fields and heat allows the researchers to tune the magnetic properties of the magnet without deforming its printed shape.
For 3D printed anisotropic bonded magnets, a one-step print and align process is the ultimate goal but still needs work to be successful. We continue to pursue that goal.—Ikenna Nlebedim
By applying magnetic alignment, the researchers were able to improve magnetic performance of the already dysprosium-free composite bonded magnet without using more critical materials. This means more economical use of expensive and critical rare earth materials, explained Nlebedim.
The Critical Materials Institute is a Department of Energy Innovation Hub led by the US Department of Energy’s Ames Laboratory and supported by the Office of Energy Efficiency and Renewable Energy’s Advanced Manufacturing Office. CMI seeks ways to eliminate and reduce reliance on rare-earth metals and other materials critical to the success of clean energy technologies.
Kinjal Gandha, Ling Li, I.C. Nlebedim, Brian K. Post, Vlastimil Kunc, Brian C. Sales, James Bell, M. Parans Paranthaman (2018) “Additive manufacturing of anisotropic hybrid NdFeB-SmFeN nylon composite bonded magnets,” Journal of Magnetism and Magnetic Materials, Volume 467, Pages 8-13, doi: 10.1016/j.jmmm.2018.07.021