Vasiliki Tsakaloudi, George Kogias, Vassilios Zaspalis
Laboratory of Inorganic Materials, Chemical Process Engineering Research Institute,
Centre for Research and Technology-Hellas, 57001 Thermi-Thessaloniki, Greece
In the present study the freeze granulation technique is applied in the manufacturing process of Mn-Zn power ferrites. The powders are prepared by the solid state reaction method and a comparison between the standard industrially used spray-drying method and the freeze granulation process with subsequent freeze drying has been carried out, in terms of granulate morphology, compaction behavior and pore size distribution, sintering behavior and magnetic performance. It apeared that the freeze granulation process enables the formation of homogeneous green compact microstructures and finally leads to sintered products of good magnetic quality. Consequently, Mn-Zn ferrites with low losses of 287 mW/cm3 (at measuring conditions f=100 kHz, B=200 mT and T=1000C) are manufactured.