Electromagnetic Interference Shielding Effectiveness Performance of Various Aluminum Foam/Cellular Structures at C-Band: A Numerical and Experimental Investigation

Metallic foam or cellular structures are of great interest due to various purposes such as cooling electronics, suppressing acoustic noise, mechanical energy absorption, and electromagnetic (EM) shielding structures. This study investigates three different aluminum foam structures, offset honeycomb (HCF), hybrid-finned honeycomb (HFHF), and lattice (LF) geometries, to determine their electromagnetic interference shielding effectiveness (SE) performances at the C-band. Herein, all the developed foams are manufactured by an innovative additive manufacturing-assisted investment casting technique. A vat polymerization 3D printing technique is used to produce polymer models of designs, and then, the models are used as the casting precursor in the investment flask mold casting process, with vacuum support to produce aluminum foam structures. Throughout the study, the fundamental parameters of each structure are changed to investigate total SE performance variations, which gives a novel glance at the related research field. In the case of a single-layer structure, the HCF structure is superior by approximate to 20 dB to HFHF and LF regarding total SE. While the contribution of the absorption and reflection components of HCF and LF are close to approximate to 5 dB deviation, the contribution of reflection is superior to absorption, close to approximate to 20 dB deviation for the HFHF structure.