In response, researchers at TU Graz - in collaboration with colleagues from the University of Vienna and Friedrich-Alexander Universität Erlangen-Nürnberg (FAU) have succeeded in manufacturing super magnets with the help of laser-based 3D printing technology delivering the required flexibility of shape, and enabling production of magnets tailored to the demands of a specific application.
The method employed uses a powdered form of the magnetic material, which is applied in layers and melted to bind the particles, resulting in components made purely of metal.
The team of scientists have now developed the process to a stage where they are able to print magnets with a high relative density while still managing to control their microstructures.
"The combination of both these features enables efficient material use because it means we can precisely tailor the magnetic properties according to the application," explained Siegfried Arneitz and Mateusz Skalon from the Institute of Materials Science, Joining and Forming at TU Graz.
The initial focus of the research group was the production of neodymium, or NdFeB, magnets. On account of its chemical properties, the rare earth metal neodymium is used as the basis for many strong permanent magnets which are crucial components for lots of important applications, including computers and smartphones. The researchers have published a detailed description of their work in the journal Materials. In other applications, however, such as electric brakes, magnetic switches and certain electric motor systems, the strong force of NdFeB magnets is unnecessary and also undesirable.
As a result,TU Graz's Institute of Materials Science, Joining and Forming, is conducting research into 3D printing of Fe-Co (iron and cobalt) magnets, which are seen as a promising alternative to NdFeB magnets in two respects: mining rare earth metals is resource intensive and the recycling of such metals is still in its infancy.
Rare earth metals also lose their magnetic properties at higher temperatures, while special Fe-Co alloys can maintain their magnetic performance at temperatures of 200° to 400° C and demonstrate good temperature stability.
