Improvement of the properties of MnZn ferrite power cores through improvements on the microstructure of the compacts

In the present work freeze drying and wet-pressing technologies are applied and evaluated in the manufacturing process of functional ceramics such as MnZn power ferrites. In particular, the implementations of freeze drying instead of spray drying and the implementation of wet pressing instead of dry uniaxial pressing are investigated. It appeared that at high frequencies there is almost 25% power loss reduction by the implementation of freeze drying instead of spray drying. At low frequencies there is almost 23% power loss reduction by the implementation of wet pressing instead of dry pressing. By introducing wet pressing technology, MnZn ferrite materials exhibiting power losses of 210 mW cm(-3) (100 kHz, 200 mT and 100 degrees C) could be synthesized. This is one of the lowest power loss values reported in the scientific or patented literature. (c) 2011 Elsevier B.V. All rights reserved.