Abstract
We have developed new powder magnetic cores with high densities from iron particles coated with new type of phosphate glass insulator of Sr-B-P-O system, which was named HDMC (High Density Magnetic Composite). They exhibit high magnetic flux density, high mechanical strength and high resistivity. To improve the properties of the HDMC, effects of addition of organic compounds to Sr-B-P-O insulator were investigated. Additon of benzotoriazole and 1, 10 phenantroline was found to increase resistivity of the HDMC. The HDMC with addition of 0.05mass% benzotriazole, which was made by compaction at 1176MPa and heat treatment at 773 K, showed following properties; density of 7.70 Mg/m3, magnetic flux densities of 1.18 T at 2 kA/m and 1.70 T at 10 kA/m, Hc of 300 A/m, resistivity of 200 μΩm, radial crushing strength of 110 MPa, and iron loss (at Bmax = 1 T, f = 400 Hz) of 400 kW/m3.
