Airfoil component wear indicator

Abstract

An example airfoil assembly includes an airfoil body extending between a leading edge, a trailing edge, a suction side, and a pressure side. The assembly further includes a first protective sheath, an indicator sheath, and a second protective sheath. The first protective sheath has an outer side and an inner side that forms a cavity for receiving at least a portion of the airfoil body. The inner side being bonded to the leading edge of the airfoil body. A portion of the indicator sheath is positioned forward the first sheath relative to the leading edge of the airfoil. A portion of the second protective sheath is positioned forward the indicator sheath relative to the leading edge of the airfoil.

1 . An airfoil assembly comprising:
 an airfoil body extending between a leading edge, a trailing edge, a suction side, and a pressure side;   a first protective sheath having an outer side and an inner side that forms a cavity for receiving at least a portion of the airfoil body, the inner side being bonded to the leading edge of the airfoil body;   an indicator sheath, at least a portion of the indicator sheath positioned forward the first sheath relative to the leading edge of the airfoil; and   a second protective sheath, at least a portion of the second protective sheath positioned forward the indicator sheath relative to the leading edge of the airfoil.   
     
     
         2 . The airfoil assembly of  claim 1 , wherein the indicator sheath is formed from a copper-based material. 
     
     
         3 . The airfoil assembly of  claim 1 , wherein the indicator sheath is a copper wire. 
     
     
         4 . The airfoil assembly of  claim 1 , wherein weld fillets secure the indicator sheath to the second protective sheath. 
     
     
         5 . The airfoil assembly of  claim 1 , wherein the second protective sheath is formed of a nickel-based metallic material. 
     
     
         6 . The airfoil assembly of  claim 1 , wherein the first protective sheath includes a first plate on the suction side of the airfoil body and a second plate on the pressure side of the airfoil body that meet at a nose near the leading edge that extends forward relative to the leading edge of the airfoil body and includes a seam where the first plate and the second plate meet, the indicator sheath having a portion forward the seam relative to the leading edge of the airfoil. 
     
     
         7 . The airfoil assembly of  claim 1 , wherein a wall thickness of the first protective sheath tapers from a nose at the leading edge of the airfoil body to a rearward end of the first protective sheath. 
     
     
         8 . The airfoil assembly of  claim 1 , wherein a portion of the second protective sheath is spaced from the first protective sheath to establish an area that is filled with an adhesive to bond the second protective sheath to the first protective sheath. 
     
     
         9 . The airfoil assembly of  claim 1 , wherein the second protective sheath has an outer side and an inner side that forms a cavity for receiving at least a portion of the indicator sheath, the inner side of the second protective sheath being bonded to the indicator sheath. 
     
     
         10 . The airfoil assembly as recited in  claim 1 , wherein the airfoil body is a composite material comprising a polymer matrix and reinforcement fibers distributed within the polymer matrix. 
     
     
         11 . The airfoil assembly as recited in  claim 1 , wherein the airfoil body includes surface portions that are covered by the first sheath and other surface portions that are not covered by the first sheath, with a ratio of the covered portion to the uncovered portion that is about 0.1-1. 
     
     
         12 . A indicator sheath for an airfoil assembly, comprising:
 an indicator sheath having an outer side and an inner side, the outer side configured to be received within a second protective sheath, the inner side forming a cavity for receiving at least a leading edge portion of a first protective sheath.   
     
     
         13 . The sheath of  claim 12 , wherein the indicator sheath is formed from a different material than the first protective sheath and the second protective sheath. 
     
     
         14 . The indicator sheath of  claim 12 , wherein the indicator sheath is formed from a copper-based material. 
     
     
         15 . The sheath of  claim 12 , wherein the leading edge portion of the first sheath includes a seam where a first plate and a second plate meet and the indicator sheath extends forward the seam relative to the leading edge portion. 
     
     
         16 . The sheath as recited in  claim 12 , wherein the indicator sheath is configured to be adhesively bonded to the first protective sheath. 
     
     
         17 . An airfoil assembly wear indicating method, comprising:
 providing an airfoil body that extends between a leading edge, a trailing edge, a suction side, and a pressure side with an indicator sheath, at least a portion of the indicator sheath secured between a first protective sheath and a second protective sheath near the leading edge of the airfoil body, the first sheath having an inner side that forms a cavity for receiving at least a portion of the airfoil body, the inner side being bonded to the leading edge of the airfoil, at least a portion of the indicator sheath is positioned forward the first protective sheath relative to the leading edge of the airfoil, and at least a portion of the second protective sheath is positioned forward the indicator sheath relative to the leading edge of the airfoil.   
     
     
         18 . The method of  claim 17 , comprising selecting the indicator sheath to be a copper-based metallic material. 
     
     
         19 . The method of  claim 17 , wherein wearing the second sheath exposes the indicator sheath.