Methods of forming thermally stable polycrystalline diamond cutters

Abstract

A method for forming a thermally stable cutting element that includes forming at least one acid infusion pathway in a polycrystalline abrasive body containing a catalyzing material to be leached; and contacting at least a portion of the at least one acid infusion pathway in the polycrystalline abrasive body with a leaching agent is disclosed.

What is claimed: 
     
         1 .- 18 . (canceled) 
     
     
         19 . A method for forming a thermally stable cutting element, comprising:
 forming a polycrystalline diamond compact of a polycrystalline diamond body attached to a substrate comprising:
 placing a mixture of diamond particles and a catalyst material adjacent a substrate; and 
 subjecting the mixture and substrate to high-pressure/high temperature conditions; 
   detaching the polycrystalline diamond body from the substrate;   forming at least one cavity in the detached polycrystalline diamond body; and   contacting the detached polycrystalline diamond body with a leaching agent.   
     
     
         20 . The method of  claim 19 , further comprising:
 re-attaching the polycrystalline diamond body to a substrate.   
     
     
         21 . The method of  claim 20 , further comprising:
 contacting an upper surface of the polycrystalline diamond body attached to the substrate to a leaching agent.   
     
     
         22 . The method of  claim 19 , further comprising:
 filling at least a portion of the at least one cavity with an intermediate material;   placing the polycrystalline diamond body adjacent a substrate material; and   subjecting the polycrystalline diamond body and substrate material to high temperature/high pressure conditions.   
     
     
         23 . The method of  claim 19 , wherein the cavity comprises a channel extending through an entire thickness of the polycrystalline abrasive body. 
     
     
         24 . The method of claim  10 , wherein the cavity extends a partial thickness into the polycrystalline abrasive body. 
     
     
         25 . The method of  claim 19 , wherein the cavity has an opening with at least one dimension of less than 1 mm. 
     
     
         26 . The method of  claim 25 , wherein the cavity has an opening with a diameter between about 10 microns and 1 millimeter. 
     
     
         27 . The method of  claim 19 , wherein the forming occurs by at least one of machining, laser cutting, and etching. 
     
     
         28 . A thermally stable cutting element, comprising:
 a polycrystalline abrasive body having at least one cavity formed in an interior portion of a working surface of the polycrystalline abrasive body.   
     
     
         29 . The thermally stable cutting of  claim 28 , further comprising:
 a substrate attached to a surface opposite the working surface of the polycrystalline abrasive body.   
     
     
         30 . The thermally stable cutting element of  claim 28 , wherein the polycrystalline abrasive body comprises at least one of polycrystalline diamond, polycrystalline diamond having at least a portion of catalyzing material removed therefrom, and polycrystalline cubic boron nitride. 
     
     
         31 . The thermally stable cutting element of  claim 28 , wherein the cavity comprises a channel extending through an entire thickness of the polycrystalline abrasive body. 
     
     
         32 . The thermally stable cutting element of  claim 28 , wherein the cavity extends a partial thickness into the polycrystalline abrasive body. 
     
     
         33 . The thermally stable cutting element of  claim 28 , wherein the cavity has an opening with at least one dimension of less than 1 mm. 
     
     
         34 . The thermally stable cutting element of  claim 33 , wherein the cavity has an opening with at least one dimension of less than 50 microns. 
     
     
         35 . A method for forming a thermally stable cutting element, comprising:
 forming at least one acid infusion pathway in a polycrystalline abrasive body containing a catalyzing material to be leached, wherein the step of forming comprises:
 removing polycrystalline abrasive material from a surface of the polycrystalline abrasive body; 
   contacting at least a portion of the at least one acid infusion pathway in the polycrystalline abrasive body with a leaching agent; and   attaching the surface of the leached polycrystalline abrasive body to a substrate by subjecting the polycrystalline abrasive body and the substrate to high pressure/high temperature sintering conditions to form a non-planar locking interface therebetween, wherein the substrate locks with the at least one acid infusion pathway of the polycrystalline abrasive body upon attachment.   
     
     
         36 . The method of  claim 35 , wherein the acid infusion pathway has an opening with at least one dimension of less than 3 mm. 
     
     
         37 . A method for forming a thermally stable cutting element, comprising:
 forming at least one acid infusion pathway in a polycrystalline abrasive body containing a catalyzing material to be leached, wherein the at least one acid infusion pathway has a diameter of less than 100 nanometers; and   contacting at least a portion of the at least one acid infusion pathway in the polycrystalline abrasive body with a leaching agent.   
     
     
         38 . The method of  claim 37 , further comprising:
 attaching the polycrystalline abrasive body to an upper surface of a substrate.   
     
     
         39 . The method of  claim 38 , wherein the step of attaching comprises subjecting the polycrystalline abrasive body and the substrate to high pressure/high temperature sintering conditions. 
     
     
         40 . The method of  claim 38 , wherein the substrate has a non-planar, non-mating upper surface. 
     
     
         41 . The method of  claim 38 , wherein the substrate has a substantially planar upper surface. 
     
     
         42 . The method of  claim 37 , wherein the at least one acid infusion pathway is formed by incorporation of a metal, cermet, or ceramic fiber into the polycrystalline abrasive body to form a material structure through which a leaching agent may more easily diffuse as compared to the polycrystalline abrasive body material. 
     
     
         43 . The method of  claim 37 , wherein the at least one acid infusion pathway is formed by incorporation of at least one discrete region into the polycrystalline abrasive body, and wherein the at least one discrete region is removed from the polycrystalline abrasive body chemically, prior to leaching. 
     
     
         44 . The method of  claim 37 , wherein the at least one acid infusion pathway is formed by incorporation of at least one discrete region into the polycrystalline abrasive body, and wherein the at least one discrete region is removed from the polycrystalline abrasive body chemically, during leaching. 
     
     
         45 . A method for forming a thermally stable polycrystalline diamond body, comprising:
 incorporating a filler material into a diamond mixture;   subjecting the filler material and the diamond mixture to a high pressure/high temperature sintering process to form a polycrystalline diamond body comprising a discrete region;
 wherein the discrete region comprises the filler material and has a material microstructure distinct from the remaining polycrystalline diamond body; and 
   contacting at least a portion of the polycrystalline diamond body with a leaching agent.   
     
     
         46 . The method of  claim 45 , wherein the step of contacting removes at least a portion of the discrete region. 
     
     
         47 . The method of  claim 45 , wherein the filler material comprises at least one material selected from the group consisting of a metal and a ceramic. 
     
     
         48 . The method of  claim 47 , wherein the filler material comprises tungsten carbide. 
     
     
         49 . The method of  claim 45 , further comprising attaching the surface of the leached polycrystalline diamond body to an upper surface of a substrate. 
     
     
         50 . The method of  claim 49 , wherein the step of attaching comprises subjecting the polycrystalline diamond body and the substrate to high pressure/high temperature sintering conditions. 
     
     
         51 . The method of  claim 49 , wherein the substrate has a non-planar, non-mating upper surface. 
     
     
         52 . The method of  claim 49 , wherein the substrate has a substantially planar upper surface.