Fugitive core tooling and method

Abstract

A ceramic core is produced by introducing a fluid ceramic core material, such as a ceramic slurry, into a core-shaped cavity formed at least in part by one or more fugitive core tooling liners residing in a back-up body, removing the ceramic core from the cavity, and removing the one or more fugitive tooling liners from the back-up die body and discarding them. The fugitive tooling liners and optional tooling inserts are used in one or more production cycles (e.g. ceramic slurry injection cycle) to make a single or multiple ceramic cores and then replaced with fresh (un-used) tooling liners and optional inserts to make other ceramic cores.

1 . Tooling for making a ceramic core, comprising a back-up body and one or more fugitive tooling liners disposed in the back-up body to form at least a portion of a core-shaped cavity. 
     
     
         2 . The tooling of  claim 1  wherein the back-up body comprises multiple parts positionable to form a tooling cavity to receive the tooling liners. 
     
     
         3 . The tooling of  claim 2  wherein first and second fugitive tooling liners are placed in the tooling cavity and each first and second tooling liner includes an outer surface having a simple geometry to match that of an adjacent inner support surface of an adjacent part of the back-up body and an inner surface that is configured to form at least a portion of the desired core surface features when the tooling liners are placed in the back-up body. 
     
     
         4 . The tooling of  claim 3  wherein the inner surfaces of the first and second fugitive tooling liners form all of the core surface. 
     
     
         5 . The tooling of  claim 3  wherein the inner surfaces of the first and second fugitive tooling liners form a portion of the core surface and surfaces of the back-up body form remaining core surface. 
     
     
         6 . The tooling of  claim 1  wherein the back-up body includes easily machined interior surfaces. 
     
     
         7 . The tooling of  claim 6  wherein the tooling liners include surfaces that mate with respective easily machined surfaces of the back-up body. 
     
     
         8 . The tooling of  claim 1  wherein the tooling liners comprise a polymer. 
     
     
         9 . The tooling of  claim 1  including one or more fugitive inserts between the tooling liners. 
     
     
         10 . The tooling of  claim 1  including one or more fugitive inserts on the tooling liners. 
     
     
         11 . The tooling of  claim 1  wherein the tooling liners form an airfoil-shaped cavity. 
     
     
         12 . A method of making a ceramic core, comprising introducing a fluid ceramic core material into a core-shaped cavity formed at least in part by one or more fugitive tooling liners in a back-up body, removing the ceramic core from the cavity, and removing the one or more fugitive tooling liners from the back-up body. 
     
     
         13 . The method of  claim 12  wherein the steps thereof are repeated using fresh, un-used tooling liners to make another ceramic core. 
     
     
         14 . The method of  claim 12  wherein the steps thereof are repeated using the same tooling liners to make another ceramic core. 
     
     
         15 . The method of  claim 12  wherein the fluid ceramic material is introduced under pressure into the cavity. 
     
     
         16 . The method of  claim 12  including placing the tool liners in the back-up body so that surfaces of the tooling liners conform to easily machined surfaces of the back-up body. 
     
     
         17 . The method of  claim 12  including injection molding the tooling liners before placing them in the back-up body. 
     
     
         18 . The method of  claim 12  including discarding the used tooling liners. 
     
     
         19 . The method of  claim 12  wherein the core-shaped cavity is formed to have an airfoil shape. 
     
     
         20 . The method of  claim 12  including placing one or more fugitive inserts between the tooling liners. 
     
     
         21 . The method of  claim 12  including placing one or more fugitive inserts on the tooling liners.