Functional materials have always played an important role in powder metallurgy (refractory metals, cutting materials such as cemented carbides, or porous materials for filter applications). The largest product group in terms of quantity was and is, however, the manufacture of pressed and sintered parts based on iron and steel. However, the two megatrends of changed mobility, which are changing with the move away from the combustion engine to the electric motor, as well as the technical breakthrough in additive manufacturing, are changing powder metallurgy permanently.
Alternative products are being sought, although many of these products are still lacking the basis in material development or are still in the field of basic research. The CD Laboratory for powder metallurgical soft magnets will now deal with special soft magnetic materials, which are predicted to have a high potential in the future.
Soft magnetic iron-based materials, so-called SMCs (soft magnetic compounds), which are characterized by the fact that they extend the concept of laminated steel sheets, as used for transformers, to the third dimension by replacing the laminated sheets with isolated Fe powder particles. These materials are used today for motors up to a frequency of approx. 1000 Hz. On the one hand, these materials are to be significantly improved through special manufacturing concepts, on the other hand, the area of application is to be expanded for significantly higher frequencies. Special alloy concepts and associated coatings should pave this way. The combination of fundamentally new coatings with an adapted subsequent heat treatment should be able to significantly increase the magnetic efficiency and thus enable components that are now necessarily covered by ferrites. However, the magnetic saturation of this group of materials is too low to meet all requirements. The metallic soft magnets currently still have too great eddy current losses, which should be massively reduced by the new material concept.
In the free research area, it is planned to set new standards with powder production on a laboratory scale for soft magnetic powders. The installation of a relatively small, flexible atomization unit is intended to raise the possibility of relatively rapid alloy development for such powders to a new level. Since many of the desired compositions will most likely not be available as raw materials (rods or wires), it is necessary to develop a manufacturing route for these materials. Powder metallurgy offers a variety of possibilities here. Mixing the powder and pressing it to forma preform, which is then compacted by extrusion, is a variant to achieve the desired preforms. These powder development can provide massive assistance in the basic investigation of the effects of SMCs, as variants can be tested here that are not available in this variety on the free market.
