Electromagnetic shielding effectiveness of amorphous metallic spheroidal-and flake-based magnetodielectric composites  

作　　者：Kun Qian Qifan Li Alexander Sokolov Chengju Yu Piotr Kulik Ogheneyunume Fitchorova Yajie Chen Chins Chinnasamy Vincent G.Harris 

机构地区：[1]Center for Microwave Magnetic Materials and Integrated Circuits,Department of Electrical and Computer Engineering,Northeastern University,Boston,MA,02115,USA [2]KRI at Northeastern University,LLC,141 South Bedford Street,Burlington,MA,01803,USA [3]Rogers Innovation Center,Rogers Corporation,141 South Bedford Street,Burlington,MA,01803,USA [4]Carpenter Technology Corporation,Reading,PA,19601,USA

出　　处：《Journal of Materials Science & Technology》2021年第24期256-263,共8页材料科学技术（英文版）

摘　　要：Flexible,lightweight,conductive materials,having both high rf losses and high permeability,are extremely desirable for applications as electromagnetic(EM)shielding.Gas atomized spherical FeSi-based ferromagnetic metallic particles,having a mean diameter of 14.6μm with a standard deviation of 7.3μm,were measured to have a room temperature saturation magnetic flux density of 1.49 T with a coercivity of 160 A/m.Ball milling of the amorphous particles led to aspect ratios from 1:1(spherical)to>100:1(flake-like).Flake-like particles,suspended in paraffin,were found to not only increase the surface area of fillers enhancing the polarization mechanism but also increase the complex permeability and complex permittivity,and thus provide broadband shielding effectiveness.A loading factor of 40 vol.%of the∼15μm diameter powders provided the largestΔW_(RL=-20 dB)of 9.49 GHz(i.e.,6.55<f<16.04 GHz)at a coating thickness of 2 mm.Overall,powder composites show a wide absorption potential above 18 GHz for<1.5 mm thicknesses.The optimized flake-based composites exhibit strong EM wave absorption with an SE of-40 dB and SE<-10 dB of 17.57 GHz at 40 vol.%filler at a thickness of 1.6 mm.

关 键 词：Amorphous particle Magnetic alloy powders Microwave absorption Electromagnetic interference shielding 

分 类 号：TB33[一般工业技术—材料科学与工程]