Preparation and Microwave Absorption Properties of FeCoNi-EG Composites Obtained by Electroless Plating Process

Abstract:

FeCoNi-expanded graphite (EG) microwave absorption composites were prepared by electroless plating process. Nickel、nickel-cobalt alloy and nickel-cobalt-iron alloy were plated to the expanded graphite, and the elemental composition, structure, magnetic and microwave absorption of these composites were investigated with the use of scanning electron microscopy, X-ray diffraction, energy dispersive spectra, hysteresis loop and electromagnetic parameter analysis. The microwave absorption properties were measured in the frequency range of 2.0-18 GHz. The results show that EG is plated symmetrical magnetic metal or their alloy, it is about 70~150nm thick. The coatings deposited from an electroless bath have the transformation of amorphous phase to crystalline phase after heat treatment 1h at 400°C.The magnetism capability of these composites is enhanced compared with pure EG. The optimum matching is 3mm thick and the maximum reflection coefficient shifts to lower frequency with the increase of thickness. The absorption property of FeCoNi-EG composite after heat treatment 1h at 400°C is the best, and when it is 3mm thick, the maximum theoretical reflection loss is about -28.8dB (the matching frequency is 13.5GHz), and the absorption bandwidth below -10dB is 8GHz. The other adsorption bandwidth below -10dB for plating Ni, Ni-Co, Ni-Fe on the surface of EG were 4.2GHz, 5.2GHz and 6.5GHz, respectively.

• Periodical: Advanced Materials Research (Volumes 396-398)
• Pages: 2322-2329
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.396-398.2322
• Online since: November 2011
• Authors: Ying Jia, Hu Cui, Zhi Yong Yu, Hou Sui Zhao, Xuan Jun Wang
• Keywords: Electroless Plating (EP), Electromagnetic Parameter, Expanded Graphite (EG), FeCoNi/EG Composite, Microwave Absorption

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