Cooled turbine blade shroud

Abstract

A process for forming a turbine blade comprises the step of forming an as-cast turbine blade having an airfoil portion and a tip shroud, wherein the forming step comprises forming at least one as-cast cooling circuit within the tip shroud.

1 - 6 . (canceled) 
     
     
         7 . A process for forming a turbine blade comprising the steps of:
 forming an as-cast turbine blade having an airfoil portion and a tip shroud: and   said forming step comprising forming at least one as-cast cooling circuit within said tip shroud.   
     
     
         8 . The process according to  claim 7 , wherein said airfoil portion forming step comprises using a primary ceramic core to form at least one radial inner passage within said airfoil portion of said turbine blade; and said at least one as-cast cooling circuit forming step comprises attaching a plurality of refractory metal cores to said primary ceramic core. 
     
     
         9 . The process according to  claim 8 , wherein said attaching step comprises joining each of said refractory cores to said primary ceramic core by inserting a plurality of tabs on each said refractory metal core into a plurality of slots in a tip of the primary ceramic core. 
     
     
         10 . The process of  claim 7 , wherein said at least one cooling circuit forming step comprises forming at least one cooling circuit at a mid-plane level of the as-cast shroud. 
     
     
         11 . The process of  claim 7 , wherein said at least one cooling circuit forming step comprises forming two cooling circuits at a mid-plane level of the as-cast shroud. 
     
     
         12 . The process of  claim 7 , wherein said forming step comprises forming each said cooling circuit with a first cooling fluid exit on one side of the shroud and at least two additional cooling fluid exits on a second side of the shroud.