Polishing systems and methods for polishing complex polycrystalline diamond compact geometries

Abstract

A method of polishing a polycrystalline diamond compact (“PDC”) portion of a cutting element of an earth-boring tool, the cutting element comprising a PDC portion and a carbide portion. The method may comprise securing the cutting element in a receptacle, which receptacle may seal off the carbide portion of the cutting element from a working fluid comprising a carrier fluid and abrasive particles, enclosing the cutting element in a pressurized chamber, filling the pressurized chamber with the working fluid, directing a pressurized flow of the working fluid from at least one inlet toward at least one surface of the PDC portion of the cutting element and out at least one outlet, and providing relative motion between the receptacle and the at least one inlet with a motion mechanism. A polishing tool for polishing the PDC portion of at least one cutting element of an earth-boring tool.

1 . A method of polishing a polycrystalline diamond compact, comprising:
 securing the polycrystalline diamond compact in a fixture;   enclosing at least a portion of the polycrystalline diamond compact within a chamber;   flowing a pressurized working fluid through the chamber between a chamber inlet and a chamber outlet and polishing at least a portion of a surface of the polycrystalline diamond compact, the pressurized working fluid comprising abrasive particles suspended within a carrier fluid.   
     
     
         2 . The method of  claim 1 , wherein the polycrystalline diamond compact is disposed on a substrate, and wherein securing the polycrystalline diamond compact in the fixture comprises sealing the substrate from the chamber such that the flowing pressurized working fluid does not contact the substrate. 
     
     
         3 . The method of  claim 1 , further comprising varying a direction of flow of the working fluid across the at least a portion of a surface of the polycrystalline diamond compact within the chamber. 
     
     
         4 . The method of  claim 3 , wherein varying the direction of flow of the working fluid across the at least a portion of a surface of the polycrystalline diamond compact within the chamber comprises providing relative motion between the polycrystalline diamond compact and the chamber inlet. 
     
     
         5 . The method of  claim 4 , wherein providing relative motion between the polycrystalline diamond compact and the chamber inlet comprises moving the chamber inlet relative to the fixture. 
     
     
         6 . The method of  claim 1 , wherein the at least a portion of a surface of the polycrystalline diamond compact is non-planar. 
     
     
         7 . The method of  claim 1 , wherein the at least a portion of a surface of the polycrystalline diamond compact comprises at least a portion of each of at least two non-coplanar surfaces of the polycrystalline diamond compact. 
     
     
         8 . The method of  claim 1 , wherein the carrier fluid comprises water. 
     
     
         9 . The method of  claim 1 , wherein the abrasive particles comprise a material selected from the group consisting of diamond, carbides, oxides and nitrides. 
     
     
         10 . The method of  claim 1 , further comprising adding a dispersant to the working fluid. 
     
     
         11 . The method of  claim 10 , wherein the dispersant is selected from a group consisting of water-based, oil-based, and water-and-oil-based compounds. 
     
     
         12 . A method of polishing a polycrystalline diamond compact portion of a plurality of cutting elements for an earth-boring tool, each of the plurality of cutting elements comprising a polycrystalline diamond compact disposed on a substrate, the method comprising:
 securing each cutting element of the plurality of cutting elements in a fixture;   enclosing at least a portion of the polycrystalline diamond compact of each cutting element of the plurality of cutting elements within a chamber;   flowing a pressurized working fluid through the chamber between a chamber inlet and a chamber outlet and polishing at least a portion of a surface of the polycrystalline diamond compact of each cutting element of the plurality of cutting elements within the chamber, the pressurized working fluid comprising abrasive particles suspended within a carrier fluid.   
     
     
         13 . The method of  claim 12 , wherein securing each cutting element of the plurality of cutting elements in the fixture comprises sealing the substrate of each cutting element of the plurality of cutting elements from the chamber such that the flowing pressurized working fluid does not contact the substrate. 
     
     
         14 . The method of  claim 12 , further comprising varying a direction of flow of the working fluid across the at least a portion of the surface of the polycrystalline diamond compact of each cutting element of the plurality of cutting elements within the chamber. 
     
     
         15 . The method of  claim 12 , wherein the at least a portion of the surface of the polycrystalline diamond compact of each cutting element of the plurality of cutting elements is non-planar. 
     
     
         16 . The method of  claim 12 , wherein the at least a portion of the surface of the polycrystalline diamond compact of each cutting element of the plurality of cutting elements comprises at least a portion of each of at least two non-coplanar surfaces of the polycrystalline diamond compact. 
     
     
         17 . The method of  claim 12 , wherein the carrier fluid comprises water, and the abrasive particles are selected from the group consisting of diamond, carbides, oxides and nitrides. 
     
     
         18 . A system for polishing a polycrystalline diamond compact, comprising:
 a housing including internal surfaces defining an enclosed chamber therein, the housing including a fixture configured to hold at least one polycrystalline diamond compact therein such that at least a portion of a surface of the at least one polycrystalline diamond compact is exposed within the chamber;   at least one fluid inlet leading into the chamber from outside the housing;   at least one fluid outlet leading out from the chamber from inside the housing;   a fluid reservoir for holding a working fluid therein;   a pump for producing flow of pressurized working fluid through the enclosed chamber within the housing and across the at least a portion of a surface of the at least one polycrystalline diamond compact exposed within the chamber; and   fluid conduits defining a circular fluid pathway extending from the fluid reservoir to the pump, from the pump to the at least one fluid inlet, and from the at least one fluid outlet to the fluid reservoir.   
     
     
         19 . The system of  claim 18 , further comprising a mechanism for varying a direction of flow of the working fluid across the at least a portion of a surface of a polycrystalline diamond compact within the chamber. 
     
     
         20 . The system of  claim 18 , wherein the fixture is configured to hold a plurality of cutting elements for an earth-boring tool, each including a polycrystalline diamond compact disposed on a substrate, therein such that at least a portion of a surface of the at least one polycrystalline diamond compact of each cutting element of the plurality is exposed within the chamber and such that the substrate of each cutting element of the plurality is sealed from the chamber.