[T16] Soft Magnetic Materials

[15E-T16-12] Combining Die Coating and Added Lubricant to Improve Magnetic Properties of Soft Magnetic Composites

*C. Höhnel¹, I. Lindemann-Geipel², T. Weißgärber^{1, 2} (1.Technische Universität Dresden, Germany, 2.Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM, Germany)

Keywords:soft magnetic composite, die wall lubrication, compaction, magnetic properties, microstructure

Iron powders with a novel coating system based on the sol-gel process were compacted by die pressing for the preparation of soft magnetic composites (SMC). The compaction was executed with die wall lubrication, added lubricant or both methods combined. The effect of different lubrication strategies will be analyzed in regard to the magnetic properties of the compacted SMC. Die wall lubrication results in high density but low resistivity. Therefore, good magnetic properties can be achieved only in direct current. Added lubricant shows lower density but higher resistivity, which reduces losses in alternating fields at higher frequencies. The combination of both methods using a smaller amount of added lubricant results in high density and high resistivity. The correlation of microstructure and electric/magnetic properties in DC/AC fields will be elucidated.