| Sendust powder and powder cores with high saturation magnetization, low loss, excellent high-frequency performance and cost-effective have prospect application. In this paper, the sendust powder and powder cores were studied in two parts, ont the one hand,the purchased sendust powder as raw material were used commercially, focusing on the surface of the insulating magnetic treatment; on the other hand the sendust powder was made with a vacuum arc casting and method of ball mill, and the incorporation of Cr, Mn.A scanning electron microscope (SEM) was used to observed powder morphology, the crystal structure of powder was detected by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) tested the powder hysteresis and saturation magnetization. The soft AC tester checked Kool soft magnetic core losses, while LCR tester measured magnetic core inductance and quality factor, and soft DC tester tested effective area and the effective length, then powder cores effective permeability were got. The results showed that:1, On the purchase of sendust powder after 20h,40h,60h milling, the extent of powder milled flat after 40h is better than 20h, powder particle size has also been fully refined, and the reunion is not obvious. The flat level of powder after 60h milled are larger, but there ane a lot of reunion flakes.2, The bought sendust powder was oxidated by hydrogen peroxide. Under concentration of 10% and 30% hydrogen peroxide, the results show that the concentration of 30% loss is small, the effective permeability is small, quality factor is larger, the saturation magnetization is smaller. Using hydrogen peroxide concentration of 30%, the processing time was 3min to 5h, power consumption is reduced with time,5h reaches to 57.33 W/kg, effective permeability increase with the oxidation time, the quality factor of oxidation prolonged rises, the saturation magnetization decrease with reaction time, but not obvious.3, Molding pressure have influence on magnetic powder cores. When the molding pressure is 1850MPa, the power loss is the smallest, magnetic permeability of the core increases with the molding pressure, magnetic core of the quality factor increases with increasing molding pressure, given a combination of factors, the decision to adopt 1850MPa was made.4, At 300℃ to 900℃, the magnetic powder was boron for 10min, the results show that with temperature increasing, magnetic core loss decreased substantially, magnetic permeability of the core temperature rises with puffed lower, the quality factor substantially increases as the temperature rises, the saturation magnetization with the extension of the basic boron time show a downward trend. At 900℃ conditions, a boric acid concentration changed from 1% to 5%. Magnetic core power loss increases with boric acid concentration decreases and then increases, when the boric acid concentration is 4%, the loss can be reduced to 40.82 W/kg, with the increase of acid concentration decreased permeability, quality factor in concentration reaches maximum 56 when the concentration is 4%, the saturation magnetization increases with concentration increasing. With the extension of time diboride, magnetic core power loss reduces, permeability decreases quality factor rises, the saturation magnetization with the extension of time and presents diboride decrease.5, The mass fraction of 0.5% to 6% Cr was doped in alloy FeSiAl standard components, with the increase of Cr content, and magnetic core loss was downward trend, when Cr content is 6%, magnetic core losses to 24.38 W/kg, the permeability reduced with increasing Cr content, the quality of magnetic cores factor increases with increasing of Cr content.6, The mass fraction of 0.5% to 2% Mn was doped in alloy FeSiAl standard components, the results show that with the increase of Mn content, the magnetic core losses reduce and then rise, reaching the Mn content of 1.5% by the lowest 35.2 W/kg. Permeability increased with Mn content, the quality factor increased and then reduced with increasing of Mn content. |
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