Methods and materials for attaching ceramic and refractory metal casting cores

Abstract

A slurry is used to secure a metallic casting core to a ceramic casting core. The slurry may be introduced between the metallic and ceramic casting cores and hardened. The slurry may comprise zircon and aqueous colloidal silica.

1 . A method for attaching a metallic casting core to a ceramic casting core comprising: 
 inserting an insertion portion of the metallic casting core into a receiving portion of the ceramic casting core; and    introducing a slurry between the metallic casting core and the ceramic casting core.    
   
   
       2 . The method of  claim 1  wherein: 
 the metallic casting core comprises a refractory metal-based substrate.    
   
   
       3 . The method of  claim 1  used to form a turbine blade core assembly or a turbine vane core assembly.  
   
   
       4 . The method of  claim 1  further comprising: 
 heating the slurry to harden the slurry.    
   
   
       5 . The method of  claim 1  further comprising: 
 vibrating the metallic casting core and the ceramic casting core during the introducing.    
   
   
       6 . The method of  claim 1  wherein: 
 the inserting is performed with the ceramic casting core in a green state.    
   
   
       7 . The method of  claim 1  wherein the slurry comprises zircon and aqueous colloidal silica.  
   
   
       8 . The method of  claim 6  wherein: 
 the slurry has an aqueous colloidal silica content of 20-30%, by weight, of a zircon content.    
   
   
       9 . The method of  claim 1  wherein: 
 the slurry comprises a surfactant.    
   
   
       10 . The method of  claim 1  wherein the slurry has: 
 a density of 2.87-2.96 g/cm 3 ;    a pH of 9-10.5; and    a viscosity of 25 ±2 cP.    
   
   
       11 . The method of  claim 1  wherein the slurry has: 
 a density of 2.87-2.96 g/cm 3 ;    a pH of 9-10.5; and    a viscosity of 18-27 cP.    
   
   
       12 . A method comprising: 
 using a slurry comprising zircon and aqueous colloidal silica to secure a metallic casting core to a ceramic casting core.    
   
   
       13 . The method of  claim 12  further comprising: 
 heating the slurry to harden the slurry.    
   
   
       14 . An apparatus comprising: 
 means for holding a ceramic casting core;    means for holding a metallic casting core with an insertion portion received in a receiving portion of the ceramic casting core; and    means for vibrating the ceramic casting core and the metallic casting core.    
   
   
       15 . The apparatus of  claim 14  in combination with: 
 said ceramic casting core;    said metallic casting core; and    a slurry comprising zircon and aqueous colloidal silica between the metallic casting core and the ceramic casting core and being vibrated by the means for vibrating.    
   
   
       16 . The apparatus of  claim 14  wherein the means for holding the metallic casting core comprises: 
 means for adjusting a relative position of the ceramic casting core and the metallic casting core.