Lockheed Martin Corporation

Martin Marietta Corporation

Gene P Shumaker

Walter B May

Paul D Rimer

Stanley Podlaseck

Edward W Sheridan

Bobby G Isler

Donald G Rollin

Roger A Purcell

Michael Griffith

An exemplary method of manufacturing a polymer matrix composite electromagnetic shielding structure includes pretreating a dry fiber reinforcement with a composition including a carrier and a conductive element, laying out the pretreated reinforcement to form a pre-form structure, applying a resin to the pre-form structure, and curing the resin at room temperature. Another exemplary method of manufacturing a polymer matrix composite electromagnetic shielding structure includes laying out a plurality of dry fiber reinforcements, placing at least one ply between any two of the plurality of dry fiber reinforcements, the ply having a non-woven including a conductive material, applying a resin to the plurality of dry fiber reinforcements and the at least one ply, and curing the resin.

Method of fabricating a polymer matrix composite electromagnetic shielding structure

A method of dispersing fibers in an electromagnetic-attenuating coating and applying the coating to a substrate. The method includes mixing a coating material of fibers and resin in a container such that the fibers are uniformly dispersed in the resin without breaking the fibers. The method also includes feeding the coating material from the container while maintaining the fibers uniformly dispersed in the resin and without breaking the fibers. In addition, the method includes applying the coating material to a substrate. The mixing is carried out by subjecting the container to an oscillatory shaking action, the feeding step is carried out by pressurizing the container and ejecting the coating material through a bottom opening in the container and the applying step is carried out by spraying the coating material on the substrate with an air-nozzle spray gun.

Method of dispersing fibers in electromagnetic-attenuating coating materials

In a radar absorbing material, first or relatively resistive fibers are combined with second or relatively conductive fibers in a dielectric binder. Preferably, the first fibers are graphite filaments and the second fibers are metal coated graphite filaments. The appropriate selection of fibers results in a material having broadband or multi-frequency RF absorbing properties.

Multi-fiber species artificial dielectric radar absorbing material and

An electromagnetic-attenuating coating having fibers uniformly dispersed in a lightly loaded dielectric matrix material. The fibers are metal-coated dielectric or semi-conductive fibers such as graphite fibers and the fibers are provided in an amount of less than 1 weight % of the coating. The dielectric matrix material is a resin material such as silicone. The fiber lengths and diameters, the material of the fibers and metal coating, the thickness and tolerance range of the metal coating and the loading of the metal coated fibers in the matrix material can be adjusted depending on the frequency range to be attenuated.

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Gene P Shumaker