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US 7,247,368 B1Granted
Stealth foam and production method
AssigneeTouchstone Research Laboratory, Ltd.
InventorDarren Kenneth Rogers
Life of this patent
Estimating the term…
Abstract
Carbon foams exhibiting a dielectric constant of from about 2 to about 6 and simultaneously an electrical resistivity in the range of between about 1.E+00 ohm-cm and about 1.E+06 ohm-cm, demonstrate excellent radar emission absorptivity in the megahertz and gigahertz ranges.
Claims16
A material comprising a carbon foam manufactured by a process comprising the steps of:
- heating particulate coal in a pressurized non-oxidizing atmosphere having a pressure in the range of about 50 psi to about 500 psi, to a temperature in the range about 300° C. to about 600° to form a green foam;
- and
- carbonizing said green foam to form a carbonized foam by heating said green foam to a maximum temperature ranging from about 600° C. to about 800° C., and soaking at this temperature for about 2 to about 30 minutes to produce a carbonized foam which exhibits a dielectric constant in the range of about 2 to about 6 and an electrical resistivity in the range of about 1.E+00 ohm-cm to about 1.E+06 ohm-cm.
A radar emissions absorbing body comprising:
- a carbon foam on a surface of a body, wherein said carbon foam has the properties of a dielectric constant in the range of about 2 to about 6 and an electrical resistivity in the range of about 15 ohm-cm to about 1.E+06 ohm-cm.
A material comprising a carbon foam having a dielectric constant from about 2 to about 6 and an electrical resistivity from about 15 ohm-cm to about 1.E+06 ohm-cm.
Dependencies are inferred from the claim text.