As concerns and awareness grow regarding the world’s rare-earth element supply, other options are starting to attract interest. One potential alternative involves additive manufacturing or 3D printing magnetic ceramics and alloys that aren’t made with rare earth elements. 

Overview of Rare-earth Magnets vs. Rare-earth-free

An important characteristic of magnets is coercivity or their ability to withstand demagnetization. This relates to the magnet’s maximum energy product. Neodymium-based magnets generally represent the maximum energy product, and commercial neodymium magnets tend to be manufactured with added heavy rare-earth dysprosium. Hard ferrites, however, provide a non-rare-earth alternative, although their maximum energy product is lower. For that reason, other rare-earth-free magnets are drawing more attention, including manganese-based alloys (e.g, manganese bismuth, manganese gallium, and manganese aluminum), which have been investigated as “gap magnets” or substitutes. While the energy product is still lower vs. neodymium, these near-net magnets (i.e., when the initial 3D fabrication is as close as possible to the size and shape of the finished product) possess other desirable qualities, including mechanical properties and high-temperature performance.    Different materials and techniques are used to 3D print permanent magnets. For instance, selective laser melting and electron beam melting have been predominantly used to produce alnico magnets. Manganese aluminum-based alloys and strontium ferrite magnets have also been successfully printed via fuse filament fabrication. Hard ferrites have been printed through stereolithography and extrusion free-forming. By incorporating magnetic powders in polymers and then printing via extrusion, fuse filament fabrication was also used to produce strontium ferrite magnets.    In certain cases, the properties of these 3D printed magnets are comparable to conventionally sourced magnets. Magnetic properties may also be enhanced or improved when you align magnetic particles with an external magnetic field during the extrusion of magnetic pastes/filaments. These advances could create opportunities for the next generation of permanent magnet applications.

Apex Magnets

Learning more efficient ways to use rare-earth-free materials can ultimately lead to a more stable supply of rare-earth magnets. While still inferior to their counterparts, rare-earth-free magnets may become a vital effort in relation to electrical machinery and smart structures.   Stay aware of all magnetic goings on by signing up for our newsletter. You can expect to receive news stories, DIY arts and crafts, and so much more. Give us a call or email us to learn more.