Methods and materials for attaching casting cores

Abstract

In a method for attaching a first casting core to a second casting core, a first portion of the first casting core is brought into engagement or close proximity with a second portion of the second casting core. The first and second portions are dipped in a ceramic slurry to form a coating around the first and second portions. The coating is hardened to form a joint between the first and second portions.

1 . A method for attaching a first casting core to a second casting core comprising: 
 bringing a first portion of the first casting core into engagement with or close proximity to a second portion of the second casting core;    dipping the first portion and second portion in a slurry to form a coating; and    hardening the coating to join or further join the first and second casting cores.    
   
   
       2 . The method of  claim 1  further comprising: 
 bringing a third portion of a third casting core into engagement with or close proximity to a fourth portion of at least one of the first and second cores and wherein said dipping, or another dipping, comprises dipping the third arid fourth portions.    
   
   
       3 . The method of  claim 1  further comprising: 
 attaching at least one additional casting core to at least one of the first and second casting cores.    
   
   
       4 . The method of  claim 1  wherein: 
 the bringing comprises contacting and holding in contact; and    the dipping is performed after the bringing.    
   
   
       5 . The method of  claim 1  wherein: 
 the bringing comprises providing a ceramic adhesive between the first portion and second portion; and    the dipping is performed after the bringing.    
   
   
       6 . The method of  claim 1  wherein: 
 the dipping comprises multiple dippings in different slurries; and    at least one of the dippings is performed after the bringing.    
   
   
       7 . The method of  claim 1  wherein: 
 the bringing comprises contacting in a fired state; and    the hardening comprises drying and does not comprise firing.    
   
   
       8 . The method of  claim 1  wherein: 
 the bringing comprises contacting in a green state; and    the hardening comprises firing with the first and second cores to also harden the first and second cores.    
   
   
       9 . The method of  claim 1  wherein: 
 the coating fully encircles the first and second portions at a junction.    
   
   
       10 . The method of  claim 1  further comprising: 
 molding the first and second casting cores.    
   
   
       11 . The method of  claim 1  wherein: 
 the bringing comprises forming a joint selected from the group consisting of: shiplap, half lap, back-locked protuberance/recess, and tongue/groove.    
   
   
       12 . The method of  claim 1  further comprising: 
 inserting an insertion portion of a metallic casting core into a receiving portion of the joined first and second casting cores.    
   
   
       13 . The method of  claim 1  used to form a turbine blade core, a turbine vane core, a seal core or a combustor core.  
   
   
       14 . The method of  claim 1  further comprising: 
 the hardening comprises heating.    
   
   
       15 . The method of  claim 1  wherein the slurry comprises zircon and aqueous colloidal silica.  
   
   
       16 . The method of  claim 1  wherein: 
 the slurry has:    a by weight zircon content; and    a by weight aqueous colloidal silica content of 20-30%, of a said zircon content.    
   
   
       17 . The method of  claim 1  wherein: 
 the slurry comprises a surfactant.    
   
   
       18 . The method of  claim 1  further comprising: 
 molding the first casting core; and    forming the second casting core from a metallic sheet.    
   
   
       19 . The method of  claim 1  wherein: 
 the first casting core comprises a molded ceramic; and    the second casting core comprises a metallic member.    
   
   
       20 . A method for investment casting comprising: 
 attaching, according to  claim 1 , first and second casting cores;    molding a sacrificial material partially over the first and second casting cores;    applying a shell to the sacrificial material;    removing the sacrificial material from the shell,    delivering molten metal to the shell at least partially in place of the sacrificial material;    allowing the molten metal to solidify;    removing the shell and first and second casting cores from the solidified metal.    
   
   
       21 . A method for attaching a first casting core to a second casting core comprising; 
 bringing a first portion of the first casting core into engagement with or close proximity to a second portion of the second casting core in a first relative position;    holding the first casting core and second casting core to maintain said first relative position;    dipping the first portion and second portion in a slurry to form a coating; and    hardening the coating to join or further join the first and second casting cores.    
   
   
       22 . The method of  claim 21  wherein: 
 the dipping and a portion of the hardening occur during the holding.    
   
   
       23 . A method for attaching a first casting core to a second casting core comprising: 
 bringing a first portion of the first casting core into engagement with or close proximity to a second portion of the second casting core in a first relative position;    applying a slurry coating over the first portion and second portion by dipping; and    hardening the slurry coating to join or further join the first and second casting cores.    
   
   
       24 . The method of  claim 23  further comprising: 
 holding with a fixture the first casting core and second casting core to maintain said first relative position during at least portions of said applying and hardening.    
   
   
       25 . The method of  claim 23  wherein: 
 the coating filly encircles the first and second portions at a junction.