Methods of fabricating a polycrystalline diamond compact including gaseous leaching of a polycrystalline diamond body

Abstract

Embodiments of the invention relate to methods of fabricating polycrystalline diamond compacts (“PDCs”) and applications for such PDCs. In an embodiment, a method of fabricating a PDC includes providing a polycrystalline diamond (“PCD”) table in which a catalyst is disposed throughout, leaching the PCD table with a gaseous leaching agent to remove catalyst from the PCD table and bonding the at least partially leached PCD table to a substrate to form a PDC.

1 . A method, comprising:
 forming a polycrystalline diamond table having catalyst distributed therethrough;   leaching the catalyst from at least a portion of the polycrystalline diamond table using a flow of a gaseous leaching agent;   infiltrating the polycrystalline diamond table with a metallic infiltrant from a substrate under conditions effective to bond the infiltrated polycrystalline diamond table to the substrate to form a polycrystalline diamond compact; and   removing at least a portion of the metallic infiltrant from the infiltrated polycrystalline diamond table of the polycrystalline diamond compact by exposing at least one working surface of the infiltrated polycrystalline diamond table to a gaseous leaching agent.   
     
     
         2 . The method of  claim 1  wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas. 
     
     
         3 . The method of  claim 1  wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof. 
     
     
         4 . The method of  claim 1 , further comprising:
 prior to the act of infiltrating, heating the at least partially leached polycrystalline diamond table under partial vacuum conditions to remove at least some leaching by-products from the leached polycrystalline diamond table generated during the act of leaching.   
     
     
         5 . The method of  claim 4  wherein heating the at least partially leached polycrystalline diamond table under partial vacuum conditions comprises:
 heating the at least partially leached polycrystalline diamond table at a temperature sufficient to sublimate the at least some leaching by-products. 
 
     
     
         6 . The method of  claim 5  wherein the temperature is above about 500° C. and below about 700° C. 
     
     
         7 . The method of  claim 1 , further comprising:
 prior to the act of infiltrating, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by chemically cleaning the leached polycrystalline diamond table.   
     
     
         8 . The method of  claim 1 , further comprising:
 prior to the act of infiltrating, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by using an autoclave under diamond-stable conditions.   
     
     
         9 . The method of  claim 1 , further comprising:
 removing at least some of the leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of removing at least a portion of the metallic infiltrant from the infiltrated polycrystalline diamond table of the polycrystalline diamond compact.   
     
     
         10 . The method of  claim 1 , further comprising reducing a non-planarity of an interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant. 
     
     
         11 . The method of  claim 10  wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant comprises substantially planarizing the interfacial surface to a flatness of about 0.00050 inch to about 0.0010 inch. 
     
     
         12 . The method of  claim 10  wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to bonding the at least partially leached polycrystalline diamond table to the substrate occurs prior to removing at least some leaching by-products from the leached polycrystalline diamond table. 
     
     
         13 . The method of  claim 1 , further comprising leaching a portion of the metallic infiltrant present in the infiltrated polycrystalline diamond table to a selected leach depth of about 50 μm to about 800 μm. 
     
     
         14 . A method, comprising:
 forming a polycrystalline diamond table having catalyst distributed therethrough;   leaching the catalyst from at least a portion of the polycrystalline diamond table using a gaseous leaching agent;   infiltrating the polycrystalline diamond table with a metallic infiltrant from a substrate under conditions effective to bond the infiltrated polycrystalline diamond table to the substrate to form a polycrystalline diamond compact;   protecting the substrate and at least a portion of the polycrystalline diamond table proximate to the substrate to limit unintended leaching; and   leaching the metallic infiltrant from a portion of the polycrystalline diamond table to define a first volume within the polycrystalline diamond table remote from the substrate and a second volume within the polycrystalline diamond table adjacent to the substrate, wherein the first volume is substantially free of the metallic infiltrant and the second volume is substantially unaffected by the leaching.   
     
     
         15 . The method of  claim 14  wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas. 
     
     
         16 . The method of  claim 14  wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof. 
     
     
         17 . The method of  claim 14 , further comprising reducing a non-planarity of an interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant. 
     
     
         18 . A method of forming a polycrystalline diamond compact, comprising:
 placing a mass of diamond particles adjacent to a substrate including a metal-solvent catalyst therein;   subjecting the mass of diamond particles and the substrate a high-pressure/high-temperature sintering process to form a polycrystalline diamond table with the metal-solvent distributed therethrough.   separating the polycrystalline diamond table from the substrate;   leaching the metal-solvent catalyst from at least a portion of the polycrystalline diamond table using a gaseous leaching agent;   removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching; and   infiltrating the polycrystalline diamond table with a metallic infiltrant from another substrate using a high-pressure/high-temperature sintering process effective to bond the infiltrated polycrystalline diamond table to the additional substrate.   
     
     
         19 . The method of  claim 18  wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas. 
     
     
         20 . The method of  claim 18  wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof.