Electromagnetic Absorption Behaviors of Ferromagnetic Fe-Cr Alloy Powder and Polymer Composites in the Radio Frequency Range

Abstract:

In order to achieve effectively high electromagnetic absorption in the radio frequency for the application of the electromagnetic absorber, we investigated annealing effect of microforged powders on electromagnetic absorption behaviors of ferromagnetic Fe-Cr alloy metal powder-polymer composites. The power loss in the far field regime was improved with increasing the microforging time in the frequency range from 50 MHz to near 1 GHz, because the magnetic permeability was slightly increased in the frequency range due to the high aspect ratio of the microforged metal powders. At higher frequency more than ~1 GHz, there was no further increased in power loss because of development of internal strain during microforging process. The magnetic permeability was significantly increased with annealing temperature due to the reduction of the lattice strain of the microforged powders. As a result, the electromagnetic absorption of ferromagnetic Fe-Cr alloy metal powder-polymer composites was highly improved.

• Periodical: Materials Science Forum (Volumes 544-545)
• Pages: 299-302
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.544-545.299
• Online since: May 2007
• Authors: Sang Woo Kim, Sung Jae Lee
• Keywords: Composite, Electromagnetic Shielding, Magnetic Permeability, Radio Frequency

References

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DOI: 10.1002/xrs.1300040415

[3] [6] [9] [12] [15] [18] [21] [24] 6G RT 500 o C 700 o C 800 o C 50M Frequency [Hz] Permeability (µµµµr') 100M 1G.

[10] [15] [20] [25] [30] [35] [40] [10] [15] [20] [25] [30] [35] [40] RT 500 o C 700 o C 800 o C 50M 6G P(loss)/P(in) (%) Frequency [Hz] Fig. 4. Relative permeability of the magnetic powder composites at different annealing temperatures. Fig. 5. Power loss of the magnetic powder composites at different annealing temperatures.