Preparation and characterization of carbonyl iron soft magnetic composites with magnesioferrite insulating coating layer
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Department of Materials and Chemistry Engineering, Pingxiang University, Pingxiang 337000, China)
2. Department of Materials and Chemistry Engineering, Pingxiang University, Pingxiang 337000, China)
Abstract: Spherical carbonyl iron (Fe) powders were coated with magnesioferrite (MgFe2O4) insulating coating layer and then mixed with epoxy-modified silicone resin (ESR). Soft magnetic composites (SMCs) were fabricated by compaction of the coated powders and annealing treatment. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS) revealed that the MgFe2O4 layer was coated on the surface of the iron powders. The magnetic properties of SMCs were determined using a vibrating sample magnetometer and an auto testing system for magnetic materials. The results showed that the SMCs prepared at 800 MPa and 550 °C exhibited a significant core loss of 167.5 W/kg at 100 kHz and 50 mT.
Key words: soft magnetic composites; in-situ oxidation preparation; magnesioferrite insulating coating layer; annealing treatment; magnetic properties