Mixed and Vacuum/Pressure Impregnated Fe/SiO₂/Shellac Composites

Abstract:

Fe/SiO₂/shellac composites based on iron powder consisting of irregularly and/or spherical shaped particles coated with SiO₂ layer or with admixed SiO₂ powder were prepared either by mixing the Fe-SiO₂ powder with shellac or by vacuum/pressure impregnation (VPI) of sintered Fe-SiO₂ compacts with shellac dissolved in ethanol. The effect of iron particle shape, density of compacts and method of shellac application on electrical resistivity and magnetic coercivity was evaluated and correlated with microstructure and features of insulating layer. For VPI composites based on spherical particles a uniformly thick insulating layer was created. This resulted in the electrical resistivity and coercivity of 780-1120 μΩ.m and 177-290 A/m. For composites based on irregularly shaped particles the shellac admixing is more preferable.

• Periodical: Materials Science Forum (Volume 782)
• Pages: 533-536
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.782.533
• Online since: April 2014
• Authors: Margita Kabátová*, Ján Füzer, Jana Füzerova, Eva Dudrová, Peter Kollár
• Keywords: Coercivity, Electrical Resistivity, Microstructure, Preparation, SMCs

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