Relationship between the Microstructure and Magnetic Properties of Fe-Si-Cr Powder Cores

Hsing-I Hsiang, Liang Fang Fan, Kuan Ting Ho

Research output: Contribution to journalArticle

Abstract

Magnetic components prepared using Fe-Si-Cr alloy powders have been widely used in high-current power inductors due to their high initial permeability, high-saturation magnetization, and excellent dc-bias characteristics. Fe-Si-Cr alloy bodies were prepared in this paper using a uniaxial molding press at different compaction pressures. Samples were then annealed at different temperatures to form a chromium-rich oxide insulating layer on the powder surface to reduce the core loss. The compaction pressure and the annealing temperature effects on the microstructure, internal strain, and insulating layer thickness and the electromagnetic properties for Fe-Si-Cr alloy powder compacts were investigated. The results showed that the relative density gradually increased with increasing compaction pressure, leading to increased saturation magnetization, thereby improving the initial permeability from 29 to 37. After annealing, the internal strain was reduced, which resulted in the initial permeability increasing substantially. Moreover, the electric resistivity and dc-superposition characteristics also increased with increasing heat treatment temperature. However, excessively thick insulating layer formed on the Fe-Si-Cr alloy powder surface resulting from annealing at too high temperature leading to initial permeability and saturation magnetization degradation.

Original languageEnglish
Article number2000407
JournalIEEE Transactions on Magnetics
Volume54
Issue number5
DOIs
Publication statusPublished - 2018 May 1

Fingerprint

Powders
Magnetic properties
Saturation magnetization
Microstructure
Compaction
Annealing
Power inductors
Electric conductivity
Chromium
Molding
Thermal effects
Temperature
Oxides
Heat treatment
Degradation

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this

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title = "Relationship between the Microstructure and Magnetic Properties of Fe-Si-Cr Powder Cores",
abstract = "Magnetic components prepared using Fe-Si-Cr alloy powders have been widely used in high-current power inductors due to their high initial permeability, high-saturation magnetization, and excellent dc-bias characteristics. Fe-Si-Cr alloy bodies were prepared in this paper using a uniaxial molding press at different compaction pressures. Samples were then annealed at different temperatures to form a chromium-rich oxide insulating layer on the powder surface to reduce the core loss. The compaction pressure and the annealing temperature effects on the microstructure, internal strain, and insulating layer thickness and the electromagnetic properties for Fe-Si-Cr alloy powder compacts were investigated. The results showed that the relative density gradually increased with increasing compaction pressure, leading to increased saturation magnetization, thereby improving the initial permeability from 29 to 37. After annealing, the internal strain was reduced, which resulted in the initial permeability increasing substantially. Moreover, the electric resistivity and dc-superposition characteristics also increased with increasing heat treatment temperature. However, excessively thick insulating layer formed on the Fe-Si-Cr alloy powder surface resulting from annealing at too high temperature leading to initial permeability and saturation magnetization degradation.",
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Relationship between the Microstructure and Magnetic Properties of Fe-Si-Cr Powder Cores. / Hsiang, Hsing-I; Fan, Liang Fang; Ho, Kuan Ting.

In: IEEE Transactions on Magnetics, Vol. 54, No. 5, 2000407, 01.05.2018.

Research output: Contribution to journalArticle

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