Northrop Grumman Systems Corporation

Robert A Petrisko

Daniel R Petrak

Gary Lee Stark

Richard E Jones

Rodolfo Enrique Diaz

Michael C Miller

Jeffrey W Peebles

Conductive and/or chemically absorptive ceramic fibers are woven with optional non-conductive/non-absorptive ceramic fibers to create a fiber reinforcement which is impregnated with a ceramic-material-producing (pre-ceramic polymer) binder and heated to create the ceramic honeycomb with controlled ohmic loss and/or chemical absorption properties. The desired properties of the honeycomb material can be provided by the conductive and/absorptive ceramic fibers alone or in combination with non-fibrous or fibrous conductive and/or absorptive ceramic material provided by the binder, typically a preceramic polymer which may or may not contain dispersed ceramic materials; after the honeycomb is formed, the non-fibrous or fibrous conductive and/or absorptive ceramic material is interspersed throughout the honeycomb. By heating the impregnated fiber reinforcement in the absence of oxygen, carbon from any carbon-containing materials within the binder remain as a part of the honeycomb material. The honeycomb can be loaded with additional carbon or carbon-containing fibers by repeating the loading and heating in the absence of oxygen steps. For applications requiring long-term thermo-oxidative resistance, refractory ceramics like pure silicon carbide can be substituted for the fibers or fillers employed.

High temperature electromagnetic radiation absorbent material and method

Ceramic honeycomb and method

A conductive woven material (2) being conductive, and preferably equally conductive, in all directions is made using woven fabric (4) having conductive weft fibers (10). The material is produced by cutting the woven fabric at a first, acute angle (19) to the side edges (12, 14) to produce trapezoidally-shaped cut fabric pieces (18). The cut fabric pieces are then reoriented so that the former side edges of the fabric are placed to abut one another to create a reconstructed fabric (20) in which the weft fibers are at acute angle (22) to the length of the reconstructed fabric. Two layers of reconstructed fabric (24, 26) are placed one upon the other, with one upside down, so that the conductive weft fibers are at an angle, preferably 90.degree., to one another so to create the conductive woven material. The conductive woven material can be used to form, for example, conductive laminates or conductive honeycomb material.

Conductive woven material and method

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Gilbert, AZ, United States of America

Robert A Petrisko