CNT-BASED SIGNATURE CONTROL MATERIAL

• US 20100271253A1
• Filed: 04/23/2010
• Published: 10/28/2010
• Est. Priority Date: 04/24/2009
• Status: Active Grant

• Current Assignee: Applied NanoStructured Solutions, LLC (Cabot Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: SHAH, Tushar K., MALECKI, Harry C.
• Granted Patent: US 8,325,079 B2
• Time in Patent Office: Days
• US Class Current: 342/2
• CPC Class Codes: H01B 1/18 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01B 1/24 the conductive material comprising carbon-silicon compounds, carbon or silicon
• CPC Class Codes: H01Q 17/002 using short elongated elements as dissipative material, e.g. metallic threads or flake-like particles
• CPC Class Codes: H05K 9/009 comprising electro-conductive fibres, e.g. metal fibres, carbon fibres, metallised textile fibres, electro-conductive mesh, woven, non-woven mat, fleece, cross-linked
• CPC Class Codes: Y10T 428/249924 Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity

Abstract

A radar absorbing composite includes a (CNT)-infused fiber material disposed in at least a portion of a matrix material. The composite absorbs radar in a frequency range from about 0.10 Megahertz to about 60 Gigahertz. The CNT-infused fiber material forms a first layer that reduces radar reflectance and a second layer that dissipates the energy of the radar. A method of manufacturing this composite includes disposing a CNT-infused fiber material in a portion of a matrix material with a controlled orientation of the CNT-infused fiber material within the matrix material, and curing the matrix material. The composite can be formed into a panel which is adaptable as a structural component of a transport vessel or missile for use in stealth applications.

Claims

1. A radar absorbing composite comprising a (CNT)-infused fiber material disposed in at least a portion of a matrix material, said composite being capable of absorbing radar in a frequency range from between about 0.10 Megahertz to about 60 Gigahertz, said CNT-infused fiber material forming a first layer that reduces radar reflectance and a second layer that dissipates the energy of the absorbed radar.

2. The composite of claim 1 further comprising a plurality of transition metal nanoparticles.

3. The composite of claim 2, wherein said nanoparticles comprise iron.

4. The composite of claim 1, further comprising a plurality of additional layers between said first layer and said second layer.

5. The composite of claim 4, wherein said plurality of additional layers comprises a stepped gradient of increasing CNT density on said CNT-infused fiber material from said first layer down to said second layer.

6. The composite of claim 4, wherein said plurality of additional layers comprises a continuous gradient of increasing CNT density on said CNT-infused fiber material from said first layer down to said second layer.

7. The composite of claim 1, wherein said first layer and said second layer comprise separate CNT-infused fiber materials.

8. The composite of claims 7, wherein said first layer comprises a CNT-infused glass fiber material.

9. The composite of claim 7, wherein said second layer comprises a CNT-infused carbon fiber material.

10. The composite of claim 1, wherein the CNTs are present in a range between about 0.001% by weight to about 20% by weight of the composite.

11. The composite material of claim 1, wherein said CNT-infused fiber material comprises a fiber material selected from glass, carbon, and ceramic.

12. The composite material of claim 1, wherein the CNTs infused on the fiber material have a controlled orientation within the composite.

13. A method of manufacturing a radar absorbing composite, said composite comprising a (CNT)-infused fiber material disposed in at least a portion of a matrix material, said composite being capable of absorbing radar in a frequency range from between about 0.10 Megahertz to about 60 Gigahertz, said CNT-infused fiber material forming a first layer that reduces radar reflectance and a second layer that dissipates the energy of the absorbed radar, the method comprising disposing a CNT-infused fiber material in a portion of a matrix material with a controlled orientation of the CNT-infused fiber material within the matrix material, and curing the matrix material, wherein the controlled orientation of the CNT-infused fiber material controls the relative orientation of CNTs infused thereon.

14. A panel comprising a composite, said composite comprising a (CNT)-infused fiber material disposed in at least a portion of a matrix material, said composite being capable of absorbing radar in a frequency range from between about 0.10 Megahertz to about 60 Gigahertz, said CNT-infused fiber material forming a first layer that reduces radar reflectance and a second layer that dissipates the energy of the absorbed radar, said panel being adaptable as a structural component of a transport vessel or missile for use in stealth applications.

15. A transport vessel comprising the panel of claim 14, wherein the CNTs infused on the fiber material have a controlled orientation within the composite material.

16. The transport vessel of claim 15, wherein said transport vessel is selected from a boat, a plane, and a ground vehicle.

17. A projectile comprising the panel of claim 14, wherein the CNTs infused on the fiber material have a controlled orientation within the composite material.