Power Molding Inductors Prepared Using Amorphous FeSiCrB Alloy Powder, Carbonyl Iron Powder, and Silicone Resin

Abstract

In this study, amorphous FeSiCrB alloy powder, carbonyl iron powder, and high-temperature heat-resistant silicone resin were used to prepare power molding inductors, and the effects of different heat treatment procedures on the magnetic properties were investigated. Two heat treatment procedures were used. Procedure 1: Amorphous FeSiCrB alloy powder was pre-heat-treated, then mixed with carbonyl iron powder and silicone resin and uniaxially pressed to prepare power inductors. Procedure 2: A mixture of amorphous FeSiCrB alloy powder, carbonyl iron powder, and silicone resin was uniaxially pressed. After dry pressing, the compacted body was heat-treated at 500 °C. Heat treatment after compaction can reduce the internal strain caused by high-pressure compaction and promote the crystallization of superparamagnetic nano-grains simultaneously. Therefore, the compacted sample after heat treatment exhibited better magnetic properties.

Magnetic Properties of the Soft Magnetic Composites Prepared Using Mixtures of Carbonyl Iron, FeSiCr, and FeSiAl Alloy Powders

“…The raw materials for this study were FeSiCr alloy powder (Epson Atmix Co., Ltd., Hachinohe, Japan), carbonyl iron powder (Jiangxi Yuean Advanced Materials Co., Ltd., Dayu, China), and FeSiAl annealed powder (Shenzhen POCO Magnetic Co., Ltd., Shenzhen, China). The FeSiAl annealed powder is produced by air-atomization (pressure range of 0.7 to 5 MPa) and then undergoes a specialized annealing procedure at 550 • C. The annealing process promotes the formation of a nanocrystalline structure within the powder, significantly reducing magnetic loss [13]. This study applied an insulating iron phosphate layer onto the carbonyl iron powder surface, employing a wet-chemical technique described in our previous study [14].…”

“…Carbonyl iron powder (CIP) has many benefits, including low cost and high saturation magnetization [11]. According to Hsiang et al [12,13], introducing CIP into FeSiCr alloy powders and amorphous alloy powder can increase the compaction density of molding coils due to significant plastic deformation during pressing, resulting in increased inductance. However, a detailed evaluation of the magnetic characteristics of soft magnetic composites made with individual and binary mixes of carbonyl iron powder, FeSiCr alloy powder, and nanocrystalline alloy powder has yet to be performed.…”

High-Power-Factor LC Series Resonant Converter Operating Off-Resonance with Inductors Elaborated with a Composed Material of Resin/Iron Powder

“…We decided to elaborate magnetic cores with this composite material of unsaturated polyester laminate resin COR61-AA-531EX and iron powder Mesh 200 with a grain size of 74 µm due to the good characteristics provided by each of these materials. Regarding the resin, this is an organic binder that presents characteristics such as excellent toughness, excellent fiberglass wet-out, high-temperature resistance, and low-laminate exothermic composition, which results in good mechanical properties (mechanical strength, plasticity, toughness) for the creation of magnetic cores in comparison with ferrite ceramic cores that are very brittle and very sensitive to temperature [26][27][28]. In addition, as shown in Figure 3, the resin provides insulating coatings for the iron powder particles, resulting in an increase in the electrical resistivity of the material, which greatly reduces the eddy currents in the core and provides a distributed air gap formed by binders, which reduces core saturation and increases magnetic flux density [29,30].…”