Lightweight, Radiation-Resistant EMI Shields

Due to their low density and exceptionally high strength and modulus, graphite fiber composites are being used increasingly for the fabrication of aircraft and spacecraft. Because of their superior mechanical properties, these composites have been replacing metals, such as aluminum alloys, in many applications. The replacement of metals has been slow, however, when high electrical conductivity is needed because of the relatively poor electrical conductivity (< 0.1 percent of metals) of composite materials. Designers have also shied away from graphite-polymer composites in applications where shielding from ionizing radiation is important, because of the poor performance of these composites.