Machining of parts having holes

Abstract

Removing of a casting core from a metal casting leaves at least one opening in a surface of the metal. The opening is filled with a sacrificial material. The metal and sacrificial material are machined at the opening. After the machining, a remainder of the sacrificial material is removed.

1 . A method comprising:
 providing a metal casting having a plurality of openings;   filling at least one opening of the plurality of openings with a sacrificial material, the filling comprising:
 at least partially immersing in a vessel containing a liquid form of the sacrificial material; and 
 the immersing providing an up-flow of the liquid out of at least one first said opening of the at least one opening responsive to introduction through at least one second said opening of the at least one opening; and 
   machining the casting and the sacrificial material at one or more of said first and second openings; and   after the machining, removing a remainder of the sacrificial material.   
     
     
         2 . The method of  claim 1  wherein:
 the filling comprises flowing an epoxy through the at least one opening and curing the epoxy to form the sacrificial material. 
 
     
     
         3 . The method of  claim 2  wherein:
 the curing comprises UV curing. 
 
     
     
         4 . (canceled) 
     
     
         5 . The method of  claim 1  wherein:
 the filling comprises applying at least one support to the casting before the immersing; and 
 during the immersing, the at least one support supports the casting to provide access for the liquid to pass through said second openings. 
 
     
     
         6 . The method of  claim 1  wherein:
 the immersing is preceded by masking with a non-liquid mask. 
 
     
     
         7 . The method of  claim 6  wherein:
 the masking forms a skirt; and 
 during the immersing, the skirt allows an exposed portion of the metal casting to lie below a surface level of the liquid. 
 
     
     
         8 . The method of  claim 7  wherein:
 the immersing is sufficient to provide said up-flow of the liquid out of said at least one first said opening within the skirt responsive to introduction through said at least one second said opening. 
 
     
     
         9 . The method of  claim 8  wherein:
 the metal casting forms a blade outer air seal precursor having an inner diameter (ID) face, an outer diameter (OD) face, upstream and downstream ends, and first and second circumferential ends, the OD face including an outer diameter (OD) well; and 
 the at least one first said opening within the skirt is along the outer diameter (OD) well. 
 
     
     
         10 . The method of  claim 8  wherein:
 the immersing is followed by exposure to a reduced pressure. 
 
     
     
         11 . The method of  claim 1  wherein:
 the immersing is followed by exposure to a reduced pressure. 
 
     
     
         12 . The method of  claim 1  wherein:
 the immersing is followed by a UV cure. 
 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . The method of  claim 1  wherein:
 the removing comprises heating. 
 
     
     
         16 . The method of  claim 1  further comprising:
 after the removing, applying a coating to the metal casting. 
 
     
     
         17 . The method of  claim 1  wherein the providing the metal casting comprises:
 casting metal for forming the metal casting in a mold cavity, the mold comprising a shell and a casting core partially embedded in the shell; and 
 removing the shell and core from the metal, the removing leaving said pluralities of openings in a surface of the metal, the openings formed by the casting core.