Nanocrystalline soft magnets are characterised by high permeability and minimal magnetisation losses. Conventional alloys such as Vitroperm 800 (Fe-Si-B-Cu-Nb) only have an average saturation polarisation of 1.2 T. Novel alloys with higher iron content such as Nanomet (Fe-Si-B-Cu-P) or Aeroperm (Fe-Co-B) achieve saturations of up to 2 T and are therefore directly competitive with electrical steel. Generally, amorphous ribbons are initially produced by melt spinning. These ribbons are converted to the nanocrystalline state by heat treatment above the crystallisation temperature. However, only toroidal core geometries can be produced by winding the ribbons. The later nanocrystalline ribbons are brittle and must be protected from environmental influences with a plastic housing which reduces the application temperature. Additionally, the nanocrystalline alloys with higher saturation tend to fast grain growth deteriorating the magnetic properties extensively. Therefore,  heat treatment must be carried out at a high heating rate.

These challenges could be solved using powder metallurgical production. The ribbons of the Finemet and Nanomet alloys were ground into flakes and then compacted using FAST/SPS with a heating rate of up to 100 K/min. The material parameters such as particle shape  and size as well as the process parameters like applied pressure, maximum temperature and holding time were analysed regarding density and magnetic properties. By selecting the optimum parameters, it was possible to achieve superior soft magnetic properties as a coercivity of 3 A/m for Vitroperm 800 and 20 A/m for Nanomet.