MATERIALS & DESIGN
·
2023
·
IF 8.4
Huaqin Huang,Jian Wang,Zhenghao Cui,Zihan Gao,Zhenyi Huang,Zhaoyang Wu
This study introduces an approach to fabricating soft magnetic composites (SMCs) that effectively address core loss while maintaining high magnetic conductivity. During the sintering process in a water vapor environment, the CeO 2 insulation layer facilitates the selective oxidation of Si while simultaneously impeding the outward diffusion of Fe and Cr. Consequently, a CeO 2 ·SiO 2 composite insulation layer forms within the FeSiCr-based SMCs. The FeSiCr-based SMCs with the CeO 2 ·SiO 2 composite insulation layer achieve a saturation magnetization of 153.1 emu/g, which is 10.9% lower than that of FeSi 3.7 Cr 4.5 compacts, and exhibits a deterioration rate lower than previously reported values. Moreover, the permeability of the FeSiCr-based SMCs remains highly stable, demonstrating outstanding insulation characteristics. The total core loss and core loss separation results further corroborate that incorporating a CeO 2 ·SiO 2 composite insulation layer leads to a more pronounced reduction in interparticle eddy current loss than using a CeO 2 insulating layer alone. This performance enhancement can be attributed to the selective oxidation of a rare metal oxide insulation layer on a ferromagnetic metal particle substrate, a technique applied to SMCs for the first time. These findings hold significant implications for the design of high-performance SMCs in miniaturized and lightweight electromagnetic devices.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Zhangqiao Zhou,Qi Li,Xian Wang
As third-generation semiconductors advance toward higher frequencies, soft magnetic composites (SMCs) for extreme conditions require concurrent low-loss properties and environmental stability. The Fe-Cr-Si-B-C alloy offers inherent corrosion resistance over other soft magnetic alloys but requires modification for salt spray environment. Insulating coatings are critical for SMCs to meet high-frequency demands. Here, Fe-Cr-Si-B-C powder, engineered via powder atomic layer deposition (PALD), are coated with a nanoscale amorphous Al 2 O 3 layer that provides electrical insulation, physical separation, and enhanced environmental stability while maintaining minimal loss. The PALD-modified SMCs achieve a core loss of 433.3 mW/cm 3 (20 mT, 1 MHz) and 99.7 % corrosion inhibition efficiency. This work proposes a design strategy for high-frequency SMCs combining low loss and extreme environmental durability.
研究领域:
材料科学
·
纳米技术
·
电磁材料
·
腐蚀工程
·
半导体技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2025
·Vol. 36
·期 20
·1-13
·
IF 2.8
Xie Linqiang,Ding Jiangtao,Liu Han,Lu Di,Yu Wanchun,Hu Te,Lin Jiayang,Cheng Zhenzhi,Gao Fei,Luo Guangsheng,Zhou Weiping
Soft magnetic composites with enhanced permeability and reduced power loss are urgently needed in the next generation of power electronics and electrical machines. However, traditional insulation techniques suffer from the uneven coating or complex process, which cannot meet these requirements. Here, the feasibility of Ba(OH) 2 as a coating layer of soft magnetic powder is explored. Due to its low melting point, Ba(OH) 2 exhibits good flowability in the molten state, enabling it to evenly coat FeSiAl particles and fill interparticle gaps, thereby forming a uniform, dense insulating layer. This novel coating strategy improves the formability of the magnetic powder cores and optimizes the cores’ soft magnetic performance. Compared with SMPCs without Ba(OH) 2 coating, FeSiAl@Ba(OH) 2 SMPCs have higher magnetic permeability (μ e = 59.5), higher quality factor ( Q max = 127.3), lower high-frequency power loss ( P cv = 2062.9 mW/cm 3 @1 MHz and 50 mT), and good DC bias performance. Our results provide a new approach for the design of insulation coatings for SMPCs, demonstrating significant application potential for high-frequency electronic devices.
研究领域:
材料科学
·
电气工程
·
应用物理学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2025
·
IF 2.5
Jia Jixiang,Wang Haiwei,Yang Guang,Lu Zhihao,Wang Rui,Wu Zhaoyang
Preparing insulating layers via interfacial solid-phase reactions is regarded as one of the most effective strategies for enhancing the magnetic performance of soft magnetic powder cores (SMPCs). However, mismatches in lattice structures between the insulating layer and the magnetic powder can cause cracking in the insulating layer, thereby compromising the stability and performance of SMPCs under operational conditions. This study presents a refined method for preparing insulating layers based on solid-phase reactions, utilizing the thermal decomposition of salt compounds in combination with powders of differing particle sizes: 99.4 μ m (S1) and 8.9 μ m (S2). Initially, the FeSiCr(S1+S2)/ZnSO 4 composite powder was synthesized through a hydrothermal method. Subsequently, FeSiCr(S1+S2)-based SMPCs with a SiO 2 @Cr 2 O 3 @ZnO (SCZ) composite insulating layer were successfully prepared by a combination of heat treatment and cold pressing. Then, we investigated the effect of varying powder ratios of different particle sizes on the microstructure and magnetic performances of FeSiCr(S1+S2)/SCZ SMPCs, and the results revealed that ZnSO 4 decomposes into solid-phase ZnO and gaseous SO 2 and O 2 during heat treatment. Among these, O 2 triggers the solid-phase reaction, causing non-magnetic Si and Cr atoms from the soft magnetic powder to migrate to the surface, leading to the formation of a composite insulating layer. The smaller FeSiCr(S2) powder fills gaps within the SMPCs and provides more sites for ZnSO 4 decomposition and insulating layer formation. This process allows for the uniform growth of an insulating layer on the surface of the magnetic powder, thereby reducing the lattice mismatch while simultaneously increasing the magnetic phase content. The optimal magnetic performance was achieved at a powder ratio of 60:40 wt% (S1:S2), with maximum saturation magnetization (172.9 emu/g), magnetic permeability (31.3 at 10 mT, 500 kHz) and low core loss (465.62 kW/m 3 at 30 mT, 200 kHz). These findings suggest that the optimized SMPCs are promising candidates for high-performance electromagnetic components. Graphical
研究领域:
材料科学
·
电磁材料
·
固态化学
·
粉末冶金
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 82
·67031-67040
·
IF 3.84
Z. Y. Wu,X. A. Fan,G. Q. Li,J. Wang,Z. H. Gan
Core–shell structured Fe-6.5 wt% Si/SiO2 particles and intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts with tunable insulating layer thickness were prepared by in situ chemical deposition combined with a subsequent spark plasma sintering process. Most of conductive Fe-6.5 wt% Si alloy particles were coated with a SiO2 insulating layer in the Fe-6.5 wt% Si/SiO2 composite compacts. The SiO2 insulating layer could increase the electrical resistivity and reduce the effective radius of the eddy current in Fe-6.5 wt% Si/SiO2 composite compacts. Therefore, the intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts presented lower core loss than those of Fe-6.5 wt% Si compacts without SiO2 insulating layer. Based on this, several types of Fe-6.5 wt% Si/SiO2 core–shell particles and intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts (with various SiO2 insulating layer thicknesses) were selectively prepared by simply varying the TEOS concentration (the volume of TEOS for each gram of Fe-6.5 wt% Si particles, ml g−1). The results indicated that the thickness of the SiO2 layer and electrical resistivity of Fe-6.5 wt% Si/SiO2 composite compacts increased with increasing the TEOS concentration from 0.1 to 0.4 ml g−1, while saturation magnetization, relative permeability and core loss displayed the reverse tendencies. The as-prepared intergranular insulated Fe-6.5 wt% Si/SiO2 composite compacts exhibited excellent magnetic properties, which inspire us to develop new high silicon containing soft magnetic cores which can be widely used in various electromagnetic devices.
研究领域:
材料科学
·
电磁学
·
冶金学
✓ 已验证
产品关联
DOI
高影响因子
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