Analysis of Electromagnetic Shielding Properties of a Material Developed Based on Silver-Coated Copper Core-Shell Spraying

Curing, Properties and EMI Absorption Shielding of Rubber Composites Based on Ferrites and Carbon Fibres

In this work, magnetic soft ferrites, namely manganese-zinc ferrite, nickel-zinc ferrite and combinations of both fillers, were incorporated into acrylonitrile-butadiene rubber to fabricate composite materials. The total content of ferrites was kept constant-300 phr. The second series of composites was fabricated with a similar composition. Moreover, carbon fibres were incorporated into rubber compounds in constant amount-25 phr. The work was focused on investigation of the fillers on absorption shieling performance of the composites, which was investigated within the frequency range 1-6 GHz. Then, the physical-mechanical properties of the composites were evaluated. The achieved results demonstrated that the absorption shielding efficiency of both composite types increased with increasing proportion of nickel-zinc ferrite, which suggests that nickel-zinc ferrite demonstrated better absorption shielding potential. Higher electrical conductivity and higher permittivity of composites filled with carbon fibres and ferrites resulted in their lower absorption shielding performance. Simultaneously, they absorbed electromagnetic radiation at lower frequencies. On the other hand, carbon fibres reinforced the rubber matrix, and subsequent improvement in physical-mechanical properties was recorded.

Analysis of Elastic Properties of Al/PET Isotropic Composite Materials Using Finite Element Method

This study uses the finite element method and numerical analysis to develop an eco-friendly composite material with shielding capabilities. A preliminary study was performed to predict the mechanical properties of the composite material. Polyethylene terephthalate and aluminum powder (AP) were selected as the matrix and enhancer, respectively. The particles of AP are spherical, with a diameter of 1 μm. Material properties were investigated as the AP volume fraction (VF) increased from 5-70%. The FEM results show that the physical properties for AP VFs improve by up to 40%, but there is no significant change in the elastic modulus, shear modulus, and Poisson's ratio at an AP VF of 50-70%. However, the numerical analysis models show that the elastic properties for AP VFs improve by up to 70%. The mechanical properties improved as the VF increased, and the FEM predicted values were reliable for VFs up to 40%. However, it was confirmed that 40% is the limit of AP VF in the FEM. In addition, the FEM and numerical analysis predictions showed that the most similar numerical analysis model was the Halpin-Tsai model. The predictions of the Halpin-Tsai model allowed prediction of the maximum VF above the FEM limit. If the correction coefficients of the FEM and numerical analysis models are derived based on the predictions of this study and future experimental results, reliable predictions can be obtained for the physical properties of composite materials.