Methods of making cutting elements and earth-boring tools and resulting cutting elements

Abstract

Methods of forming cutting elements may involve providing a thermally stable polycrystalline table and a substrate portion located adjacent to the thermally stable polycrystalline table in a mold. A metal material may be provided over the substrate portion on a side of the substrate portion opposing the thermally stable polycrystalline table in the mold, the metal material exhibiting a melting temperature of less than 1,320° C. A mixture of particles may be distributed on the metal material in the mold. The mold and its contents may be exposed to a temperature less than 1,320° C. and pressure may be applied to the mixture of particles to cause the mixture of particles to coalesce and form a substrate and to at least partially melt the metal material to flow, infiltrate the substrate portion, and wet the thermally stable polycrystalline table and the substrate to form an attachment therebetween.

1 . A method of forming a cutting element, comprising:
 providing a thermally stable polycrystalline table and a substrate portion located adjacent to the thermally stable polycrystalline table in a mold, the thermally stable polycrystalline table comprising interbonded grains of a superhard material and interstitial spaces among the interbonded grains of the superhard material, the thermally stable polycrystalline table being at least substantially devoid of catalyst material used to form intergranular bonds among the interbonded grains of the superhard material;   providing a metal material over the substrate portion on a side of the substrate portion opposing the thermally stable polycrystalline table in the mold, the metal material exhibiting a melting temperature of less than 1,320° C.;   distributing a mixture of particles comprising a plurality of hard particles and a plurality of particles comprising a matrix material on the metal material in the mold; and   exposing the mold and its contents to a temperature less than 1,320° C. and applying pressure to the mixture of particles to cause the mixture of particles to coalesce and form a substrate and to at least partially melt the metal material to flow, infiltrate the substrate portion, and wet the thermally stable polycrystalline table and the substrate to form an attachment therebetween.   
     
     
         2 . The method of  claim 1 , wherein heating the mold to at least partially melt the metal material to flow, infiltrate the substrate portion, and wet the thermally stable polycrystalline table comprises infiltrating the metal material into interstitial spaces among interbonded grains of the material of the thermally stable polycrystalline table. 
     
     
         3 . The method of  claim 1 , wherein providing the substrate portion located adjacent to the thermally stable polycrystalline table comprises providing a portion of a substrate having a thickness less than a thickness of the coalesced substrate between the thermally stable polycrystalline table and the layer of metal. 
     
     
         4 . The method of  claim 3 , wherein providing the thermally stable polycrystalline table comprises:
 forming the polycrystalline table and concurrently attaching the polycrystalline table to the portion of the substrate using a conventional HTHP process; and   at least substantially completely removing catalyst material and matrix material from the polycrystalline table and the portion of the substrate.   
     
     
         5 . The method of  claim 4 , further comprising placing the polycrystalline table and the portion of the substrate in a support structure prior to removing the catalyst material and the matrix material. 
     
     
         6 . The method of  claim 5 , wherein placing the polycrystalline table and the portion of the substrate in the support structure comprises placing the polycrystalline table and the portion of the substrate in a state of compression. 
     
     
         7 . The method of  claim 3 , wherein attaching the polycrystalline table to the portion of the substrate comprises attaching the polycrystalline table to a portion of a substrate comprising a cermet material having a hard particle phase and a matrix phase comprising a material that is resistant or impervious to conventional leaching agents. 
     
     
         8 . The method of  claim 1 , wherein exposing the mold and its contents to a temperature less than 1,320° C. comprises exposing the mold and its contents to a temperature between about 400° C. and about 1,250° C. 
     
     
         9 . The method of  claim 8 , wherein exposing the mold and its contents to a temperature between about 400° C. and about 1,250° C. comprises exposing the mold and its contents to a temperature of about 1,100° C. 
     
     
         10 . The method of  claim 1 , wherein applying pressure comprises applying between about 4,500 psi and about 30,000 psi to the contents of the mold. 
     
     
         11 . The method of  claim 1 , further comprising providing a preformed substrate component in the mold proximate the mixture of particles. 
     
     
         12 . A method of making an earth-boring tool, comprising:
 placing a thermally stable polycrystalline table and a substrate portion located adjacent to one another in a container, the thermally stable polycrystalline table at least substantially devoid of catalyst material used to form intergranular bonds among the interbonded grains of the superhard material;   placing a metal material adjacent to the substrate portion on a side of the substrate portion opposite the thermally stable polycrystalline table in the container;   placing a mixture comprising hard particles and particles of a matrix material, a preformed substrate component, or the mixture comprising the hard particles and the particles of the matrix material and the preformed substrate component adjacent to the metal material on a side of the metal material opposite the substrate portion in the container; and   heating the container and its contents while applying pressure, forming a substrate from the mixture, the preformed substrate component, or the mixture and the preformed substrate component, at least partially melting the metal material, infiltrating the substrate portion with the metal material, and wetting the thermally stable polycrystalline table and the substrate with the metal material to form an attachment therebetween.   
     
     
         13 . The method of  claim 12 , wherein heating the container and its contents comprises exposing the container and its contents to a temperature less than 1,320° C. and at least partially melting the metal material. 
     
     
         14 . The method of  claim 12 , wherein heating the container and its contents comprises subjecting the container and its contents to hot isostatic pressing or rapid omnidirectional compaction. 
     
     
         15 . The method of  claim 12 , further comprising:
 forming the polycrystalline table and concurrently attaching the polycrystalline table to the portion of the substrate using a high-temperature/high-pressure process; and   at least substantially completely removing catalyst material and matrix material from the polycrystalline table and the portion of the substrate.   
     
     
         16 . The method of  claim 15 , further comprising placing the polycrystalline table and the portion of the substrate in a support structure before removing the catalyst material and the matrix material. 
     
     
         17 . The method of  claim 16 , wherein placing the polycrystalline table and the portion of the substrate in the support structure comprises placing the polycrystalline table and the portion of the substrate in a state of compression. 
     
     
         18 . A cutting element for an earth-boring tool, comprising:
 a substrate;   a thermally stable polycrystalline table comprising interbonded grains of a superhard material, the thermally stable polycrystalline table at least substantially devoid of catalyst material used to form intergranular bonds among the interbonded grains of the superhard material;   a substrate portion interposed between the thermally stable polycrystalline table and the substrate; and   a metal material attaching the substrate to the substrate portion, the metal material extending from adjacent to the substrate, through the substrate portion, and partially into the thermally stable polycrystalline table,.   
     
     
         19 . The cutting element of  claim 18 , wherein a melting temperature of the metal material is less than 1320° C. 
     
     
         20 . The cutting element of  claim 1 , wherein the substrate portion has a thickness less than a thickness of the substrate.