RMC-defined tip blowing slots for turbine blades

Abstract

A process for forming an airfoil portion of a turbine engine component, such as a turbine blade, is described. The process comprises the steps of placing a ceramic core having a configuration of a passageway to be formed in the airfoil portion within a mold, attaching a refractory metal core element to the ceramic core to stabilize a tip region of the ceramic core, and casting the airfoil portion.

1 . A process for forming an airfoil portion of a turbine engine component comprising the steps of:
 positioning a ceramic core having a configuration of a passageway to be formed in said airfoil portion;   attaching a refractory metal core element to said ceramic core to stabilize a tip region of said ceramic core;   creating a mold about the ceramic core and refractory metal core element; and   casting said airfoil portion.   
   
   
       2 . The process of  claim 1 , further comprising locating said ceramic core relative to said mold with said refractory metal core element. 
   
   
       3 . The process of  claim 2 , wherein said locating step comprises providing a refractory metal core element having at least one leg. 
   
   
       4 . The process of  claim 3 , wherein said refractory metal core element providing step comprises providing a refractory metal core element having a plurality of legs. 
   
   
       5 . The process of  claim 3 , further comprising removing said ceramic core so as to form said passageway and subsequently removing said refractory metal core element and thereby leaving at least one cooling slot in a tip region of said airfoil portion. 
   
   
       6 . The process of  claim 5 , wherein said removing step comprises leaving a plurality of cooling slots in said tip region. 
   
   
       7 . The process of  claim 5 , further comprising machining a plurality of film cooling holes in said airfoil portion in the vicinity of said passageway formed by said ceramic core. 
   
   
       8 . In combination, a ceramic core for forming a passageway in a cast airfoil portion and means for stabilizing a tip region of said ceramic core, said stabilizing means comprising a refractory metal core element. 
   
   
       9 . The combination of  claim 8 , wherein said refractory metal core element comprises a solid portion and a plurality of legs depending from said solid portion. 
   
   
       10 . The combination of  claim 9 , wherein each said legs has an angled portion and a base portion and said base portion of said legs is joined together by a lower portion. 
   
   
       11 . A refractory metal core element comprising a solid portion and a plurality of spaced apart legs depending from said solid portion, each of said legs having a first portion adjacent said solid portion, a base portion, and an angled portion intermediate said first portion and said base portion so that said base portion is laterally offset from said solid portion. 
   
   
       12 . A refractory metal core element according to  claim 11 , further comprising a lower portion connecting each base portion. 
   
   
       13 . A turbine engine component having an airfoil portion with a tip region, a recessed shelf in said tip region, and a plurality of slots in said recessed shelf through which a cooling fluid flows, said slots being located along a pressure side of said tip region. 
   
   
       14 . The turbine engine component according to  claim 13 , further comprising said slots being oriented primarily radially outwards and being angled towards said pressure side. 
   
   
       15 . The turbine engine component according to  claim 13 , further comprising a passageway within said tip region and each of said slots communicating with said passageway. 
   
   
       16 . The turbine engine component according to  claim 15 , further comprising a plurality of cooling holes machined in said pressure side and communicating with said passageway. 
   
   
       17 . The turbine engine component according to  claim 15 , wherein said passageway comprises a laterally-oriented cavity.