Magnets. Image: stoatphoto/Shutterstock
Researchers in the US have successfully demonstrated 3D-printed permanent magnets that outperform bonded rivals – conserving critical materials is an added bonus.
Additive manufacturing has caught up on bonding alternatives when it comes to magnets, with the US department of defence making a major breakthrough in the world of magnetics.
Using a 3D-printing device called the Big Area Additive Manufacturing (BAAM) machine, scientists at Oak Ridge National Laboratory (ORNL) have fabricated isotropic, near-net-shape, neodymium-iron-boron (NdFeB) bonded magnets.
Comparable or better
Reporting comparable or better magnetic, mechanical and microstructural properties, the results have been published in Scientific Reports.
“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.
The use of 3D-printing techniques means various shapes and sizes are possible, with no tooling and far more time-efficient processes.
Traditional injection moulding would require the expense of creating a new mould and tooling for each. With additive manufacturing, however, the forms can be crafted simply and quickly using CAD, according to Li.
This isotropic, neodymium-iron-boron bonded permanent magnet was 3D-printed at DOE’s Manufacturing Demonstration Facility at ORNL. Image: ORNL
Melt and start again
The additive manufacturing process began with composite pellets consisting of 65pc isotropic NdFeB powder and 35pc polyamide (Nylon 12). The pellets were melted, compounded, and extruded by BAAM, using a layer-by-layer method, into desired forms.
“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 of the report, John Ormerod.
“Many of our customers are excited to explore the commercial impact of this technology in the near future,” he stated.
The team reported almost zero waste from this process, claiming the presented method “significantly simplifies manufacturing of near-net-shape bonded magnets [and] enables efficient use of rare earth elements, thus contributing towards enriching the supply of critical materials”.
Composite pellets are melted, compounded, and extruded layer-by-layer into desired forms. Image: ORNL
Big year
Magnets have attracted added interest this year, with one of the three Nobel Prize-winning physicists this year credited for his background in magnetics.
Duncan Haldane discovered how topological concepts can be used to understand the properties of chains of small magnets found in some materials.
In Ireland, Tyndall is focused on a separate strand called integrated magnetics, which it hopes will revolutionise chip management in the near future.
With the likes of Paul McCloskey and Santosh Kulkarni leading the charge, Tyndall prides itself as a global leader in this area, referring to integrated magnets on integrated circuits as ‘magic’.
