Fabricating hollow components

Abstract

A method of fabricating a component having an internal void, the method comprising the steps of: i) providing a core having a shape corresponding to the internal void of the component; ii) compacting a powder around the core to form a compacted powder body around the core; iii) removing the core; and iv) heating the compacted powder body to consolidate the compacted powder body.

We claim: 
     
         1 . A method of fabricating a component having an internal void, the method comprising the steps of:
 i) providing a core having a shape corresponding to the internal void of the component;   ii) compacting a powder around the core to form a compacted powder body around the core;   iii) removing the core; and   iv) heating the compacted powder body to consolidate the compacted powder body.   
     
     
         2 . The method of  claim 1  comprising assembling one or more pre-compacted pieces of the component in or around the core prior to compacting the powder around the core and the pre-compacted pieces to form the compacted powder body. 
     
     
         3 . The method of  claim 1  wherein the core comprises tooling configured to hold the core in position relative to the compacted powder body during the step of compacting the powder around the core. 
     
     
         4 . The method of  claim 3  comprising removing the tooling prior to removing the core. 
     
     
         5 . The method of  claim 1  wherein step (iii) comprises heating the compacted powder body to melt or volatilise the core. 
     
     
         6 . The method of  claim 1  wherein step (ii) comprises applying isostatic pressure to form the compacted powder body. 
     
     
         7 . The method of  claim 6 , wherein the compacted powder body is formed by cold isostatic pressing of the powder. 
     
     
         8 . The method of  claim 1  comprising a subsequent step v) of hot isostatic pressing the consolidated powder body to densify the component. 
     
     
         9 . The method of  claim 1  wherein the core comprises an internal volume and a passage extending from the internal volume to an external surface of the powder body, wherein step ii) comprises applying isostatic pressure to the powder via a fluid surrounding the powder body and extending within the internal volume. 
     
     
         10 . The method of  claim 9  wherein the core is defined by an inner elastomeric container and the powder is contained within an outer container. 
     
     
         11 . The method of  claim 1  wherein the component is a torque carrier for an epicyclic gearbox. 
     
     
         12 . The method of  claim 1  wherein the powder is metallic.