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Journal of Materials Science

, Volume 41, Issue 18, pp 5926–5936 | Cite as

Investigations into sol-gel silica and silica hybrid coatings for dielectromagnetic soft magnetic composite applications

  • Y. X. Pang
  • S. N. B. Hodgson
  • B. Weglinski
  • D. Gaworska
Article

Abstract

A series of inorganic and organic–inorganic hybrid silica coatings were synthesised by a sol-gel process from tetraethoxysilane (TEOS) and methyltrimethoxysilane (MTMS) precursors, and used to investigate their effectiveness as insulation materials in dielectromagnetic soft magnetic composites. The coating materials and coated iron powders were analysed by FTIR, electron and atomic force microscopy. Results showed that introduction of the organic phase imparted desirable hydrophobicity and flexibility to the coating, whilst still providing effective electrical insulation at temperatures up to 500 °C. The hybrid coatings covered the iron particle surface very effectively and formed continuous coatings that could remain intact even after compaction at pressures up to 900 MPa, depending on the coating amount. Initial magnetic characterisations are also encouraging. As a result, such hybrid-coated iron powders can be considered suitable candidates as heat-treatable high-performance dielectromagnetics.

Keywords

Coating Material Iron Powder Iron Particle Hybrid Coating Dielectric Coating 

Notes

Acknowledgements

The support of the European Union Fifth Framework Growth programme (Project–G1RD-CT-2001-00538) for this work is gratefully acknowledged.

References

  1. 1.
    Persson M, Jansson P, Jack AG, Mecrow BB (January 1996) Metal Power Report, pp 24–28Google Scholar
  2. 2.
    Lefebvre LP, Pelletier S, Gelinas C (1997) J Magnet Magnetic Maters 176(2–3):93CrossRefGoogle Scholar
  3. 3.
    Wêgliňski B (1990) Rev Powder Metal Phys Ceram Freund Publish House 4(2):79Google Scholar
  4. 4.
    Jansson P, Larsson L (2002) Phosphate coated iron powder and method for the manufacturing thereof. US patent US6348265Google Scholar
  5. 5.
    Satsu Y, Katayama H, Ito Y, Takahashi A Treatment solution for forming insulating layers on magnetic particles. US Patent US6344273Google Scholar
  6. 6.
    Hanejko FG, Ellis G (2000) Annealable insulated metal based powder particles. Worldwide Patent WO0030835Google Scholar
  7. 7.
    TDK Corporation (1998) Dust core, ferromagnetic powder composition therefor, and method of making European Patent EP0869517Google Scholar
  8. 8.
    Skoglund P, Andersson O, Knutsson P, Vidarsson H (2004) Soft magnetic powders comprising insulated particles and a lubricant selected from organo-silanes, -titanates,-aluminates and –zirconates and a process for their preparation, Worldwide Patent WO2004056508Google Scholar
  9. 9.
    Klein LC (1985) Ann Rev Mater Sci 16:227CrossRefGoogle Scholar
  10. 10.
    Hammiche A, Pollock HM, Song M, Hourston DJ (1996) Meas Sci Technol 7:142CrossRefGoogle Scholar
  11. 11.
    Bajorek R, Bajorek J (2003) Proc VII Sympozjum Pomiarów Magnetycznych, Warszawa, PaździernikGoogle Scholar
  12. 12.
    De D, Kundu D, Karmakar B, Ganguli D (1993) J Non-Cryst Solids 155:253CrossRefGoogle Scholar
  13. 13.
    Krihak M, Shahriari MR (1996) Optical Mater 5:301Google Scholar
  14. 14.
    Bertoluzza A, Fagnano C, Morelli M/A, Gottardi V, Guglielmi M (1982) J Non-Cryst Solids 48:117CrossRefGoogle Scholar
  15. 15.
    Gallardo J, Galliano P, Duran A (2000) J Sol-Gel Sci Technol 19(1–3):393CrossRefGoogle Scholar
  16. 16.
    Izumi K, Minami N, Uchida Y (1998) Key Eng Mater 150:77CrossRefGoogle Scholar
  17. 17.
    Preiss H, Berger LM, Braun M (1995) Carbon 33(12):1739CrossRefGoogle Scholar
  18. 18.
    Hu Y (2000) J Mater Sci 35(12):3155CrossRefGoogle Scholar
  19. 19.
    Ye Z, Hultman L, Kjellén L (2004) In: Proceedings of PM2004, Vienna, Austria, October 2004, pub. European Powder Metallurgy AssociationGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  • Y. X. Pang
    • 1
  • S. N. B. Hodgson
    • 1
  • B. Weglinski
    • 2
  • D. Gaworska
    • 2
  1. 1.School of Science and TechnologyUniversity of TeessideMiddlesbrough, Tees ValleyUK
  2. 2.Institute of Electrical Machines, Drives and MetrologyWroclaw University of TechnologyWroclawPoland

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