A research center in Spain has been working on ways to solve recent supply chain issues. One of these issues is a shortage of materials to make magnets. Their answer? Recycle ferrite residue by treating it and mixing it with ABS for 3D printing.
The mixing of ferrite with a polymer isn’t the key though, instead the trick is in the processing. The team collected strontium ferrite waste and ground it to a powder. Heating to the point of calcination (about 1000C) creates a superior material with a 350% increase in coercitivity and a 25% increase in remanence over the original waste material.
The material could just be recycled conventionally, but the team created ABS filament bearing the magnetic particles. The resulting prints retain their magnetic properties and allow for low-temperature production of magnets in a variety of geometries. In addition, the magnetic material is chemically inert, so applications that would need to coat a conventional magnet could benefit.
The researchers mention that ferrite magnets are environmentally more friendly than rare-earth magnets. That may be true, but our guess is the rare-earth magnet properties will keep them in use regardless of being able to 3D print ferrite.
We’ve seen 3D-printed magnets before, a few times actually. We still don’t totally grok how they work.