Propeller blade with metallic foam spar core

Abstract

According to one embodiment, a propeller blade includes a metallic foam core and a structural layer that surrounds at least a portion of the metallic foam core.

1 . A propeller blade comprising:
 a metallic foam core; and   a structural layer that surrounds at least a portion of the metallic foam core.   
     
     
         2 . The propeller blade of  claim 1 , further comprising:
 a layer of fiberglass at least partially disposed between the metallic foam core and the structural layer.   
     
     
         3 . The propeller blade of  claim 1 , further comprising:
 a layer of an adhesive material at least partially disposed between the metallic foam core and the structural layer.   
     
     
         4 . The propeller blade of  claim 1 , further comprising:
 a root disposed within the structural layer at an end of the propeller blade.   
     
     
         5 . The propeller blade of  claim 1 , further comprising:
 a foam core formed of a non-metallic foam in operable contact with the metallic foam core and surrounded by the structural layer.   
     
     
         6 . The propeller blade of  claim 5 , wherein the foam core is formed of polyurethane foam, polyisocyanurate foam, or polymethacrylimide foam. 
     
     
         7 . The propeller blade of  claim 1 , wherein the metallic foam is one of: an aluminum metallic foam and a titanium metallic foam. 
     
     
         8 . The propeller blade of  claim 1 , wherein the metallic foam is an open celled metallic foam. 
     
     
         9 . The propeller blade of  claim 1 , wherein the metallic foam is a closed celled metallic foam. 
     
     
         10 . The propeller blade of  claim 1 , further comprising:
 one of a leading and a trailing edge formed of metallic foam.   
     
     
         11 . A method of forming a propeller blade comprising:
 forming a metallic foam core; and   disposing a structural layer over at least a portion of the metallic foam core.   
     
     
         12 . The method of  claim 11 , further comprising:
 applying an adhesive material to the metallic foam core before disposing the structural layer.   
     
     
         13 . The method of  claim 11 , further comprising:
 forming a non-metallic core; and   joining a portion of the non-metallic foam core to the metallic foam core;   wherein disposing the structural layer over at least a portion of the metallic foam core includes also disposing the structural layer over at least a portion of the non-metallic foam core.   
     
     
         14 . The method of  claim 13 , wherein the non-metallic core is formed of polyurethane foam, polyisocyanurate foam, or polymethacrylimide foam. 
     
     
         15 . The method of  claim 11 , wherein the metallic foam is one of: an aluminum metallic foam and a titanium metallic foam. 
     
     
         16 . The method of  claim 11 , wherein the metallic foam is an open celled metallic foam. 
     
     
         17 . The method of  claim 11 , wherein the metallic foam is a closed celled metallic foam.