Papers by Keyword: Soft Magnetic Composites

Abstract: This paper investigates the magnetic and electrical properties of iron silicone resin soft magnetic composites. Scanning electron microscopy, energy dispersive X-ray spectroscopy analysis, distribution maps and density measurements confirm that the particles surface layer contains a thin layer of silicone resin with complete coverage of powders surface. The thickness of silicone resin film is averagely 120nm according to the results of transmission electron microscopy. Magnetic measurements show that the silicone resin insulation has a greater heat resistance than the conventional phosphate insulation, which enables stress reliving during annealing at higher temperature (600°C) without a large increase in magnetic loss. The results of annealing at 600°C show that the electrical resistivity increased from 8μΩ·m for SOMALOY^TM samples to 55μΩ·m for the silicone insulated composites produced in this work.

Abstract: Hysteresis modeling plays an important role for the designers of magnetic circuits. The paper considers the effect of processing temperature on magnetic properties of SMC cores. The hysteresis loops of the SMC cores are described using two recent modifications of phenomenological models.

Abstract: This paper investigates the effect of heat treatment on the magnetic properties of nanocrystalline Fe-Ni-Si powders prepared by mechanical alloying method which can be used in soft magnetic composites fabrication. Fe-85%, Si-10% and Ni-5% alloys were prepared using a vibrating disc mill. The magnetic properties of the samples were measured by a vibrating sample magnetometer (VSM) and the microstructural properties of the un annealed sample were measured by XRD and SEM. Three samples were annealed in three different temperatures from 500 °C to 600 °C and were compared with a sample without annealing. It was found that with increasing the annealing temperature, stress relieving and crystallite size increased whereas microstrain and saturation magnetization decreased.

Abstract: Sendust soft magnetic composites coated by a thin Ba-B-P-O system insulating layer were produced; SEM spectroscopy and Energy dispersive X-ray analysis spectroscopy confirmed that thin layers of Ba-B-P-O system covered the alloy powders. The influence of various compaction pressures on composites permeability, DC properties and total loss was investigated. The Fe-Si-Al magnetic powder core with compaction pressure of 1932MPa, annealing temperature of 953K with a permeability of 94, a total loss of 108 mW/cm³.

Abstract: In this paper, iron powder with high purity is covered by a Mn-Zn ferrite layer, and the effect of amount of ferrite on the microstructure and magnetic properties are investigated. The morphology of the samples was characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. It was shown that the particle surface layer contains a thin insulating layer of Mn-Zn ferrite, with high particle surface coverage. The magnetic measurements on samples were carried out using a B-H curve analyzer and an AC performance tester at Bm=50mT. The results indicate that the Mn-Zn ferrite coated samples have excellent frequency characteristics compared with uncoated samples. Also, the composites with 4wt% ferrite show a good combination of magnetic permeability and magnetic loss in the range 0.8-150 kHz.

Abstract: In this paper, the effect of heat treatment processing on magnetic properties of Fe-3.5Si soft magnetic composite has been investigated. The thermal treatment improved the magnetic properties of Fe-3.5Si SMC materials. With the treatment temperature increasing, the permeability and eddy loss of the composites increase and the core loss and hysteresis loss decrease. The magnetic properties would be deteriorated at too high temperature. Annealed temperature at 750°C for 60min, the Fe-3.5Si soft magnetic composite has the optimum overall magnetic properties.

Abstract: The main objective of this paper is to investigate the suitability of Soft Magnetic Composite (SMC) material SOMOLOY1000 for a Switched Reluctance Generator (SRG) through electromagnetic, thermal and vibration characteristics employing extensive Finite Element Analysis. The fabrication aspects of Soft Magnetic Composite Switched Reluctance Generator (SMC-SRG) using preform material blanks utilizing indigenous machining process have been delineated. The static and transient electromagnetic characteristics have been obtained through the electromagnetic finite element analysis software MagNet6.22.1 while the thermal and vibration aspects have been studied through coupled field Finite Element Analysis employing the multi physics software ANSYS10 while the Impulse hammers excitation - free vibration test using RT Pro Photon data acquisition system facilitated the experimental determination of vibration characteristics. The study concludes that the advantages of less weight , low torque ripple, low eddy current losses, reduction in vibration level of stator structure coupled with the ability to maintain precise mechanical dimensional tolerance may present SMC-SRG a viable candidate in standalone wind energy conversion systems meant for rural and remote area electrification scheme.

Abstract: The Fe-Si-Al soft magnetic composites were produced by cold pressing of water-atomized Fe-Si-Al powder using organic binder. The effect of shaping pressure, annealing temperature, magnetic annealing and dielectric content on properties of Fe-Si-Al soft magnetic composites was investigated. The results showed that increasing shaping pressure increases density and radial crushing strength of Fe-Si-Al soft magnetic cores, and decreases coercivity and total loss. Increasing annealing temperature can increase effective permeability and decrease total loss owing to decreasing hysteresis loss, and over-annealing (＞660°C) can deteriorate magnetic properties. The magnetic annealing can decrease total loss of Fe-Si-Al magnetic powder core. Increasing dielectric content can reduce the eddy current loss of Fe-Si-Al magnetic powder core and decrease the real part of permeability. Fe-Si-Al magnetic powder core with shaping pressure of 1800 MPa, annealing temperature of 660 °C and dielelctric content of 0.7% presented the optimum magnetic properties with an effective permeability of 127, a total loss of 78mW/cm3 and a radial crushing strength of 18MPa.