Advantages of the Use of Metal Foams for Electromagnetic Shielding

Abstract

Metal foams are very interesting materials in new emerging technologies as aeronautic, spatial research, auto-motion or heat exchanger, but there are other areas in which these materials could be advantageous. Here is a new proposal for using these materials in electromagnetic shielding. The goal is to demonstrate that, although having a smaller effective electrical conductivity than massive materials, it is possible to attain operative electromagnetic shielding with a reduction of mass and, in addition, to bring together in a single product a supplementary protection against vibrations, impact, noise, etc., as corresponds to the well-known properties of porous materials. In terms of the operating frequency, conductivity and thickness of the metallic foams the electromagnetic screening was calculated. It is shown how to guarantee a specified shielding the necessary thickness in porous materials with respect to massive metals obeys to a quadratic relation.