Electrically-conductive, thermally-insulating structure and method

Abstract

An electrically-conductive, thermally-insulating structure includes a thermally-insulating layer having a thermal conductivity of no more than about 3.5×10 −3 W/hr·cm·° K and an electrically-conductive layer, applied to the thermally-insulating layer, which has an electrical resistivity of no more than about five ohms at 700° C. The thermally-insulating layer can comprise a plurality of microballoons to decrease the density of the thermally-insulating layer.

What is claimed is:  
     
         1 . An electrically-conductive, thermally-insulating coating, comprising: 
 a thermally-insulating layer having a thermal conductivity of no more than about  3.5×10-   −3  W/hr·cm·° K; and    an electrically-conductive layer applied to the thermally-insulating layer, the electrically-conductive layer having an electrical resistivity of no more than about five ohms at 700° C.    
     
     
         2 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the thermally-insulating layer has a thermal conductivity of no more than about 8.7×10 −4  W/hr·cm·° K.  
     
     
         3 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the electrically-conductive layer has an electrical resistivity of no more than about two ohms at 700° C.  
     
     
         4 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the thermally-insulating layer further comprises a plurality of microballoons.  
     
     
         5 . An electrically-conductive, thermally-insulating coating, according to  claim 4 , wherein at least some of the plurality of microballoons are made of a material selected from the group consisting of glass and ceramic.  
     
     
         6 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the thermally-insulating layer has a plurality of microballoons in the range of about two percent by volume to about 25 percent by volume.  
     
     
         7 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the material of the thermally-insulating layer is a material selected from the group consisting of a silicone-based elastomer and a phenolic-based polymer.  
     
     
         8 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the material of the electrically-conductive layer is a metal.  
     
     
         9 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the thermally-insulating layer has a thickness of at least 1.5 mm.  
     
     
         10 . An electrically-conductive, thermally-insulating coating, according to  claim 1 , wherein the electrically-conductive layer has a thickness of at least 0.05 mm.  
     
     
         11 . A sheathing for an apparatus comprising: 
 a base layer for providing a base structure to the sheathing;    a thermally-insulating layer applied to the base layer, the thermally-insulating layer having a thermal conductivity of no more than about 3.5×10 −3  W/hr·cm·° K; and    an electrically-conductive layer applied to the base layer, the electrically-conductive layer having an electrical resistivity of no more than about five ohms at 700° C.    
     
     
         12 . A sheathing for an apparatus, according to  claim 11 , wherein the thermally-insulating layer has a thermal conductivity of no more than about 8.7×10 −4  W/hr·cm·° K.  
     
     
         13 . A sheathing for an apparatus, according to  claim 11 , the electrically-conductive layer has an electrical resistivity of no more than about two ohms at 700° C.  
     
     
         14 . A sheathing for an apparatus, according to  claim 11 , wherein the thermally-insulating layer further comprises a plurality of microballoons.  
     
     
         15 . A sheathing for an apparatus, according to  claim 11 , wherein at least some of the plurality of microballoons are made of a material selected from the group consisting of glass and ceramic.  
     
     
         16 . A sheathing for an apparatus, according to  claim 11 , wherein the thermally-insulating layer has a plurality of microballoons in the range of about two percent by volume to about 25 percent by volume.  
     
     
         17 . A sheathing for an apparatus, according to  claim 11 , wherein the material of the thermally-insulating layer is a material selected from the group consisting of a silicone-based elastomer and a phenolic-based polymer.  
     
     
         18 . A sheathing for an apparatus, according to  claim 11 , wherein the material of the electrically-conductive layer is a metal.  
     
     
         19 . A sheathing for an apparatus, according to  claim 11 , wherein the thermally-insulating layer has a thickness of at least 1.5 mm.  
     
     
         20 . A sheathing for an apparatus, according to  claim 11 , wherein the electrically-conductive layer has a thickness of at least 0.05 mm.  
     
     
         21 . A device capable of flight comprising: 
 a skin capable of enclosing at least a portion of the device;    a thermally-insulating layer applied to the skin layer, the thermally-insulating layer having a thermal conductivity of no more than about 3.5×10 −3  W/hr·cm·° K; and an electrically-conductive layer applied to the thermally-insulating layer, the electrically-conductive layer having an electrical resistivity of no more than about five ohms at 700° C.    
     
     
         22 . A device capable of flight, according to  claim 21 , wherein the thermally-insulating layer has a thermal conductivity of no more than about 8.7×10 −4  W/hr·cm·° K.  
     
     
         23 . A device capable of flight, according to  claim 21 , wherein the electrically-conductive layer has an electrical resistivity of no more than about two ohms at 700° C.  
     
     
         24 . A device capable of flight, according to  claim 21 , wherein the thermally-insulating layer further comprises a plurality of microballoons dispersed therein.  
     
     
         25 . A device capable of flight, according to  claim 24 , wherein at least some of the plurality of microballoons are made of a material selected from the group consisting of glass and ceramic.  
     
     
         26 . A device capable of flight, according to  claim 21 , wherein the thermally-insulating layer has a plurality of microballoons in the range of about two percent by volume to about 25 percent by volume.  
     
     
         27 . A device capable of flight, according to  claim 21 , wherein the material of the thermally-insulating layer is a material selected from the group consisting of a silicone-based elastomer and a phenolic-based polymer.  
     
     
         28 . A device capable of flight, according to  claim 21 , wherein the material of the electrically-conductive layer is a metal.  
     
     
         29 . A device capable of flight, according to  claim 21 , wherein the thermally-insulating layer has a thickness of at least 1.5 mm.  
     
     
         30 . A device capable of flight, according to  claim 29 , wherein the electrically-conductive layer has a thickness of at least 0.05 mm.  
     
     
         31 . A method for applying an electrically-conductive, thermally-insulating coating to a surface comprising the steps of: 
 applying a layer of thermally-insulating material having a thermal conductivity of no more than about 3.5×10 −3  W/hr·cm·° K onto the surface;    applying a layer of electrically-conductive material having an electrical resistivity of no more than about five ohms at 700° C. onto the layer of thermally-insulating material.    
     
     
         32 . A method for applying an electrically-conductive, thermally-insulating coating to a surface, according to  claim 31 , wherein the step of applying the layer of the electrically-conductive material is accomplished by a method selected from the group of plasma spraying, two-wire arc spraying, and flame spraying.  
     
     
         33 . A method for applying an electrically-conductive, thermally-insulating coating to a surface, according to  claim 31 , further comprising the step of removing some of the thermally-insulating material to produce a desired shape of the layer of the thermally-insulating material.  
     
     
         34 . A method for applying an electrically-conductive, thermally-insulating coating to a surface, according to  claim 31 , wherein the thermally-insulating material is sprayed onto the surface during the step of applying the layer of the thermally-insulating material.