Composition and method to form displacements for use in metal casting

Abstract

A method to form a displacement, the method including disposing a powder blend comprising a plurality of ground ceramic particles and a plurality of ground resin particles into a mold, densifying the powder blend while in the mold, heating the mold to form a first displacement, impregnating said first displacement with a polymer precursor compound to form a second displacement, and heating the second displacement to form a third displacement.

We claim: 
     
         1 . A method to form a displacement, comprising:
 disposing a powder blend comprising a plurality of ground ceramic particles and a plurality of ground resin particles into a mold;   densifying said powder blend while in said mold;   heating said mold to form a first displacement;   impregnating said first displacement with a polymer precursor compound to form a second displacement; and   heating said second displacement to form a third displacement.   
     
     
         2 . The method of  claim 1 , wherein said impregnating step comprises:
 immersing said first displacement in a liquid mixture comprising said polymer precursor compound;   monitoring a weight increase for said first displacement;   when a weight of said first displacement no longer increases with time, determining that said second displacement is formed.   
     
     
         3 . The method of  claim 1 , wherein said heating said second displacement to form said third displacement step comprises heating said second displacement at about 1000° C. for about 24 hours. 
     
     
         4 . The method of  claim 1 , further comprising heating said first displacement at about 1000° C. for about 24 hours before impregnating said first displacement with said polymer precursor compound to form said second displacement. 
     
     
         5 . The method of  claim 1 , wherein said plurality of ground ceramic particles comprises a maximum dimension less than about 150 microns. 
     
     
         6 . The method of  claim 1 , wherein said plurality of ground resin particles comprises a maximum dimension less than about 100 microns. 
     
     
         7 . The method of  claim 1 , wherein said polymer precursor compound is selected from the group consisting of furfuryl alcohol, phenol formaldehyde oligomer, acetone-furfural, furfuryl alcohol-phenol oligomer, polyvinyl chloride oligomer, polyvinylidene chloride oligomer, polyacrylonitrile oligomer, and cellulose. 
     
     
         8 . The method of  claim 7 , wherein said polymer precursor compound is furfuryl alcohol. 
     
     
         9 . The method of  claim 1 , wherein said third displacement comprises glassy carbon moieties having ceramic particles disposed therein. 
     
     
         10 . The method of  claim 9 , wherein said glassy carbon moieties comprise a first polymer having a structure: 
       
         
           
           
               
               
           
         
       
     
     
         11 . The method of  claim 9 , wherein said glassy carbon moieties comprise a second polymer having a structure: 
       
         
           
           
               
               
           
         
       
     
     
         12 . The method of  claim 9 , wherein said glassy carbon moieties comprise a fullerene having a structure:    
     
     
         13 . The method of  claim 1 , wherein said powder blend comprises a plurality of ground ceramic particles, a plurality of ground resin particles, and a plurality of reinforcing fibers. 
     
     
         14 . The method of  claim 13 , wherein said plurality of reinforcing fibers each comprises a length of about 200 microns. 
     
     
         15 . The method of  claim 14 , wherein said plurality of reinforcing fibers are formed from uncoated milled fiber glass. 
     
     
         16 . The method of  claim 1 , wherein said powder blend comprises a plurality of ground ceramic particles, a plurality of ground resin particles, and a cylindrical graphite member. 
     
     
         17 . The method of  claim 16 , wherein said cylindrical graphite member is partially encapsulated by said powder blend when disposing into said mold.