Out-of-autoclave and alternative oven curing using a self heating tool

Abstract

Method and apparatus for curing composite material to form composite structures are provided. A curing tool in one embodiment includes a curing tool that includes cured nano tube impregnated resin. At least two conductors are formed in the nano tube impregnated resin. The curing tool also includes a forming surface portion. The forming surface portion includes cured composite material of pre-preg material. The curing tool further includes at least a first insulation layer that separates the cured composite material from the nano tube impregnated resin.

1 . A method of curing composite material to form a composite structure, the method comprising:
 laying up and forming pre-preg material on a forming surface of cured pre-preg material of a composite structure forming tool; and   passing current through nano tube impregnated resin within the forming tool to heat the tool internally to cure the pre-preg material.   
     
     
         2 . The method of  claim 1 , wherein laying up and forming pre-preg material further comprises:
 applying and pressing the pre-preg material on the forming surface of the forming tool.   
     
     
         3 . The method of  claim 1 , wherein passing current through the nano tubes in the tool further comprises:
 creating a voltage potential between adjacent conductive strips in the tool.   
     
     
         4 . The method of  claim 3 , wherein creating the voltage potential between adjacent conductive strips further comprises:
 coupling alternating current to the conductive strips.   
     
     
         5 . A curing tool comprising:
 cured nano tube impregnated resin;   at least two conductors formed in the nano tube impregnated resin;   a forming surface portion including cured composite material of pre-preg material; and   at least a first insulation layer separating the cured composite material from the nano tube impregnated resin.   
     
     
         6 . The curing tool of  claim 5 , further comprising:
 a support base portion of cured composite material; and   at least one second insulation layer separating the support base portion of the cured composite material from the cured nano tube impregnated resin.   
     
     
         7 . The curing tool of  claim 6 , wherein at least one of the first and second insulation layers is a layer of cured glass ply. 
     
     
         8 . The curing tool of  claim 6 , further comprising:
 the support base portion, the at least second insulation layer and a portion of the cured nano tube impregnated resin have aligned passages to the at least two conductors; and   a conductive wire for each aligned passage, each conductive wire passing through associated aligned passages, each conductive wire coupled to an associated conductor.   
     
     
         9 . The curing tool of  claim 8 , further comprising:
 a power supply coupled to the plurality of conductive wires; and   a controller configured to control the power supply.   
     
     
         10 . The curing tool of  claim 9 , wherein the controller is configured to vary the power of the power supply to adjust heat produced by the curing tool. 
     
     
         11 . The curing tool of  claim 9 , wherein the power supply supplies an alternating current. 
     
     
         12 . The curing tool of  claim 5 , wherein the at least two conductors are conductive strips positioned relatively parallel to each other and spaced select distances apart.