For the processing of microparticles in the range of 5-200 µm jet milling and target milling techniques are employed at Fraunhofer IWKS. During a jet milling process comminution is achieved solely by interparticle collisions and therefore no machine wear and contamination of the powder material takes place. Moreover we offer the possibility of the new target milling technique where particles are accelerated on a ceramic target. By varying the classifying wheel speed favored particles sizes can be extracted while finest powders are separated by using a cyclone. Communition is suitable for any material hardness value.
Jet milling and target milling processes are used for temperature sensitive materials (toner, pigments), very hard materials (SiC, Al2O3), mineral raw material or when a high degree of purity of the powders is required. These processes have a high importance in particular for the microparticle processing of rare earth containing magnetic alloys. Although being very prone to oxidation these powders can be milled under inert gas atmospheres down to average particle sizes in the range of 2-5 µm. The milled material can afterwards be transported in inert conditions for further processing.