Way to manufacture inserts for steam cooled hot gas path components

Abstract

A method for forming inserts for steam cooled hot gas path components involves casting the inserts and laser drilling the cast inserts with the ceramic casting core still in place. Thereafter, the ceramic core is removed through the use of a leachant. By laser drilling the holes with the ceramic core still in place, the ceramic core acts as a backer during the laser drilling which results in more precise drilling of the inserts and reduced processing time.

What is claimed is:  
     
         1 . A method of forming inserts for steam cooled hot gas path components in a turbine, said method comprising: 
 casting the geometrical configuration of the insert; and    laser drilling impingement holes in the cast insert without removing a ceramic casting core of the cast insert.    
     
     
         2 . A method as claimed in  claim 1 , wherein the ceramic casting core is removed by leachant.  
     
     
         3 . A method as claimed in  claim 2 , wherein said casting comprises pressure casting.  
     
     
         4 . A method as claimed in  claim 2 , wherein said casting comprises centrifugal casting.  
     
     
         5 . A method as claimed in  claim 2 , wherein said casting comprises squeeze casting.  
     
     
         6 . A method as claimed in  claim 2 , wherein said casting comprises counter gravity casting.  
     
     
         7 . A method as claimed in  claim 1 , wherein the inserts are made of a Ni-base superalloy.  
     
     
         8 . A method as claimed in  claim 2 , wherein the inserts are made of a Ni-base superalloy.  
     
     
         9 . A method as claimed in  claim 3 , wherein the inserts are made of a Ni-base superalloy.  
     
     
         10 . A method as claimed in  claim 4 , wherein the inserts are made of a Ni-base superalloy.  
     
     
         11 . A method as claimed in  claim 5 , wherein the inserts are made of a Ni-base superalloy.  
     
     
         12 . A method as claimed in  claim 6 , wherein the inserts are made of a Ni-base superalloy.