Method of investment casting chaplet

Abstract

A method of supporting a soluble insert structure within a mould die ceramic injection moulding (CIM) process, the method comprising the steps of: forming at least one chaplet that supports the soluble insert structure within the die, the chaplet being formed of a ceramic material that has substantially similar physicochemical properties to the main internal core structure; and positioning the chaplet to contact the soluble insert structure to the die, the soluble insert being spaced away from an edge of the mould die. The chaplet may comprise a refractory material or a combination of refractory materials.

We claim: 
     
         1 . A method of supporting a soluble insert structure within a mould die ceramic injection moulding (CIM) process, the method comprising the steps of: forming a soluble insert structure, forming at least one chaplet that supports the soluble insert structure within the die, the chaplet being formed of a ceramic material that has substantially similar physicochemical properties to the soluble insert structure; and positioning the chaplet to contact the soluble insert structure to the die, the soluble insert being spaced away from an edge of the mould die. 
     
     
         2 . The method as claimed in  claim 1 , wherein the chaplet comprises a refractory material or a combination of refractory materials. 
     
     
         3 . The method as claimed in  claim 2 , wherein the refractory material is selected from silica, zirconia, alumina, alumina-silicate and combinations thereof. 
     
     
         4 . The method as claimed in  claim 1 , wherein the chaplet is adhered to the surface of the soluble insert or the die using glue. 
     
     
         5 . The method as claimed in  claim 1 , wherein the chaplet is adhered to the surface of the soluble insert by contacting the chaplet with the surface of the soluble insert and melting either the surface of the chaplet or of the soluble insert. 
     
     
         6 . The method as claimed in  claim 1 , wherein the chaplet is adhered to the die by contacting the chaplet with the die and melting either the surface of the chaplet or the surface of the die where the chaplet is to be contacted. 
     
     
         7 . The method as claimed in  claim 4 , wherein the chaplet is mounted using location features on the die. 
     
     
         8 . The method as claimed in  claim 5 , wherein the chaplet is mounted using location features on the die. 
     
     
         9 . The method as claimed in  claim 1 , wherein the resulting soluble core and the chaplet have a bulk density in the range of around 1.3-2.5 g/cc. 
     
     
         10 . The method as claimed  claim 1 , wherein the resulting soluble core and the chaplet have a core that has a porosity of around 20-40%. 
     
     
         11 . The method as claimed  claim 1 , wherein the resulting soluble core and the chaplet are made of silica in the rage of around 30-98% weight. 
     
     
         12 . The method as claimed in  claim 1 , wherein the CIM material used to form the soluble core and the chaplet compromises a binder in a range of around 10-25% weight. 
     
     
         13 . The method as claimed  claim 1 , for use in the production of vanes, blades or seals for gas turbine engines. 
     
     
         14 . The method as claimed  claim 1 , further comprising injection moulding an object around the soluble insert structure and the at least one chaplet within the mould die.