Abstract: An absorber includes a plurality of shredded foam particles and a plurality of fiber whiskers. The fiber whiskers are interspersed among, and attach to the shredded foam particles to create a foam-fiber mixture. A curable adhesive is added to the foam-fiber mixture and the cured mixture is molded to form the radar absorber. The fiber whiskers are less than about two weight percent of the absorbers. The foam particles are preferably formed by shredding scrap foam. The particles are generally irregularly shaped and the size of the particles can be expressed as having a mean size of about 1/8" to 1" diameter, although the particles are not necessarily spherical. The fibers are about 1/8" to 3/4" in length and have a diameter of about 7.3 microns. To form the absorber, shredded foam particles are mixed with fiber whiskers, and the fiber whiskers attach themselves to the surface of the shredded foam particles.

Abstract: An electromagnetic energy absorber provides a base having an electrically conductive ground plane positioned thereover. At least one dielectric and one impedance layer are positioned over the ground plane or surface on a side thereof opposite the base. An external most dielectric skin seals the structure. Additional alternating dielectric and impedance layers can be positioned over the first dielectric and impedance layers. The impedance layer, can be formed from a resistive sheet formed into a broken pattern that can comprise a series of geometric shapes spaced from each other. The broken pattern is sized to vary the specific impedance of the sheet. The resistive sheet can be combined with a series of composite dielectric layers to form an integral composite structure. Three resistive sheet layers can be provided with predetermined spacings from the ground surface and predetermined impedance to effect broadband absorption characteristics.

Abstract: An electromagnetic energy absorbing structure provides a base structure having an electrically conductive ground plane positioned thereover. At least one dielectric and one impedance layer are positioned over the ground plane or surface on a side thereof opposite the base. An external most dielectric skin seals the structure. Additional alternating dielectric and impedance layers can be positioned over the first dielectric and impedance layers. The dielectric layer can be constructed from syntactic foam with impedance layers formed from patterns of conductive dipoles. The impedance layer, can alternatively, be formed from a resistive sheet formed into a broken pattern that may comprise a series of geometric shapes spaced from each other. The resistive sheet can be combined with a series of composite dielectric layers to form an integral composite structure.

Abstract: Metallic fillers are provided which are stabilized against corrosion. The metallic fillers are stabilized by treating the surface of the filler particles wtih a triazole, preferably an aromatic triazole. This may be accomplished either by pretreating the filler with a solution of the triazole, or by adding the triazole to a polymeric composition containing a metallic filler.Polymeric compositions are further provided, e.g. compositions for microwave absorption, comprising a polymeric binder, a metallic filler and a triazole.