Composites with Controllable Conductivity layers for Hyper frequency Applications – 3CAH

The aim of the 3CAH project is to design new composite materials presenting controllable conductivities. The composite structures generally associate hearts and skins dielectric materials which ensure the mechanical behaviour of the structure. To obtain increased electromagnetic performances, these skins can be also materials with dielectric losses and magnetic. Introduction of dielectric losses within the skin structures is often carried out with charged resin, for reasons of costs and facility. Unfortunately, technologies of the composite structures evolve to the realization of parts per infusion or transfer of resin to the detriment of the thermoset ones. These processes will be used more and more for the realization of parts without having recourse to autoclaves, but are not very well adapted for resins loaded with carbon black. We thus propose to introduce the dielectric losses on the level of glass fibre, and to regulate the loading ratio to obtain various conductivities. Different synthesis ways will be studied during project, and a prototype of radar absorbing structure will be constructed and will be evaluated in anechoic room. One of the interests of these new processes is to have materials inspiring by processes already tested for reasons of costs, but also of perenniality knowing that a military use in the decade to come. The civil applications are also considered for the control of the propagation in dense environments of electromagnetic pollution.
The technical program is shared between 2 teams, one academic (Ecole Centrale Paris, Laboratory of the mechanics of Soils, Structures and Materials (LMSSMat), UMR8579 CNRS), and the research centre of EADS (EADS Innovations Works).