Systems, methods and assemblies for processing superabrasive materials

A method of processing a polycrystalline diamond material includes exposing at least a portion of a polycrystalline diamond material to a processing agent for processing at least a portion of the polycrystalline diamond material. The method further includes applying a body force to the volume of processing agent while at least the portion of the polycrystalline diamond material is exposed to the processing agent, and heating at least one of the processing agent and at least the portion of the polycrystalline diamond material exposed to the processing agent during application of the body force to the processing agent.

BACKGROUND

Wear-resistant, superabrasive materials are traditionally utilized for a variety of mechanical applications. For example, polycrystalline diamond (“PCD”) materials are often used in drilling tools (e.g., cutting elements, gage trimmers, etc.), machining equipment, bearing apparatuses, wire-drawing machinery, and in other mechanical systems.

Conventional superabrasive materials have found utility as superabrasive cutting elements in rotary drill bits, such as roller cone drill bits and fixed-cutter drill bits. A conventional cutting element typically includes a superabrasive layer or table, such as a PCD table. The PCD table is formed and bonded to a substrate using an ultra-high pressure, ultra-high temperature (“HPHT”) process. The cutting element may be brazed, press-fit, or otherwise secured into a preformed pocket, socket, or other receptacle formed in the rotary drill bit. In another configuration, the substrate may be brazed or otherwise joined to an attachment member such as a stud or a cylindrical backing. Generally, a rotary drill bit may include one or more PCD cutting elements affixed to a bit body of the rotary drill bit.

Conventional superabrasive materials have also found utility as bearing elements in thrust bearing and radial bearing apparatuses. A conventional bearing element typically includes a superabrasive layer or table, such as a PCD table, bonded to a substrate. One or more bearing elements may be mounted to a bearing rotor or stator by press-fitting, brazing, or through other suitable methods of attachment. Typically, bearing elements mounted to a bearing rotor have superabrasive faces configured to contact corresponding superabrasive faces of bearing elements mounted to an adjacent bearing stator.

Superabrasive elements having a PCD table are typically fabricated by placing a cemented carbide substrate, such as a cobalt-cemented tungsten carbide substrate, into a container or cartridge with a volume of diamond particles positioned on a surface of the cemented carbide substrate. A number of such cartridges may be loaded into a HPHT press. The substrates and diamond particles may then be processed under HPHT conditions in the presence of a catalyst material that causes the diamond particles to bond to one another to form a diamond table having a matrix of bonded diamond crystals. The catalyst material is often a metal-solvent catalyst, such as cobalt, nickel, and/or iron that facilitates intergrowth and bonding of the diamond crystals.

In one conventional approach, a constituent of the cemented-carbide substrate, such as cobalt from a cobalt-cemented tungsten carbide substrate, liquefies and sweeps from a region adjacent to the volume of diamond particles into interstitial regions between the diamond particles during the HPHT process. In this example, the cobalt acts as a catalyst to facilitate the formation of bonded diamond crystals. Optionally, a metal-solvent catalyst may be mixed with diamond particles prior to subjecting the diamond particles and substrate to the HPHT process. The metal-solvent catalyst may dissolve carbon from the diamond particles and portions of the diamond particles that graphitize due to the high temperatures used in the HPHT process. The solubility of the stable diamond phase in the metal-solvent catalyst may be lower than that of the metastable graphite phase under HPHT conditions. As a result of the solubility difference, the graphite tends to dissolve into the metal-solvent catalyst and the diamond tends to deposit onto existing diamond particles to form diamond-to-diamond bonds. Accordingly, diamond grains may become mutually bonded to form a matrix of polycrystalline diamond, with interstitial regions defined between the bonded diamond grains being occupied by the metal-solvent catalyst.

In addition to dissolving diamond and graphite, the metal-solvent catalyst may also carry tungsten and/or tungsten carbide from the substrate into the PCD layer. Following HPHT sintering, the tungsten and/or tungsten carbide may remain in interstitial regions defined between the bonded diamond grains.

The presence of the solvent catalyst in the diamond table may reduce the thermal stability of the diamond table at elevated temperatures. For example, the difference in thermal expansion coefficient between the diamond grains and the solvent catalyst is believed to lead to chipping or cracking in the PCD table of a cutting element during drilling or cutting operations. The chipping or cracking in the PCD table may degrade the mechanical properties of the cutting element or lead to failure of the cutting element. Additionally, at high temperatures, diamond grains may undergo a chemical breakdown or back-conversion in the presence of the metal-solvent catalyst. At extremely high temperatures, portions of diamond grains may transform to carbon monoxide, carbon dioxide, graphite, or combinations thereof, thereby degrading the mechanical properties of the PCD material.

Accordingly, it is desirable to remove a metal-solvent catalyst from a PCD material in situations where the PCD material may be exposed to high temperatures. Chemical leaching is often used to dissolve and remove various materials from the PCD layer. For example, chemical leaching may be used to remove metal-solvent catalysts, such as cobalt, from regions of a PCD layer that may experience elevated temperatures during drilling, such as regions adjacent to the working surfaces of the PCD layer.

While chemical leaching is effective at removing metal-solvent catalysts from interstitial regions of a PCD layer, the process of chemical leaching is often lengthy, requiring days or weeks to complete in order to achieve a desired leach depth. Additionally, conventional chemical leaching techniques often involve the use of highly concentrated, toxic, and/or corrosive solutions, such as aqua regia and mixtures including hydrofluoric acid (HF), to dissolve and remove metal-solvent catalysts from polycrystalline diamond materials. The use of highly toxic and corrosive leaching agents can present a danger to individuals and may cause significant damage to the substrate over time.

SUMMARY

The instant disclosure is directed to methods, assemblies, and apparatuses for processing polycrystalline diamond materials. In various embodiments, a method of processing a polycrystalline diamond material may comprise exposing at least a portion of a polycrystalline diamond material to a volume of processing agent for processing at least a portion of a catalyst material from interstitial spaces within the polycrystalline diamond material. The processing agent may comprise, for example, a leaching agent for leaching a catalyst material from interstitial spaces within at least the portion of the polycrystalline diamond material. In additional embodiments, the processing agent may comprise a cleaning agent for cleaning the portion of the polycrystalline diamond material. The method may further comprise applying an elevated body force to the volume of processing agent while at least the portion of the polycrystalline diamond material is exposed to the volume of processing agent, and applying a selected temperature to at least one of the volume of processing agent and at least the portion of the polycrystalline diamond material exposed to the volume of processing agent during application of the elevated body force to the volume of processing agent.

In at least one embodiment, the body force may comprise at least one of a gravitational body force and a centrifugal body force. The processing agent may comprise a liquid solution and the elevated body force may comprise a body force sufficient to prevent a phase change of the liquid solution at a selected temperature. The temperature may comprise a temperature greater than or less than a temperature required for a phase change of the liquid solution under atmospheric conditions. In various embodiments, applying the elevated body force may comprise rotating the volume of processing agent and the polycrystalline diamond material about a rotational axis.

In some embodiments, applying the elevated body force may comprise disposing another volume of fluid adjacent to the volume of processing agent. In one example, the other volume of fluid may have a density greater than the density of the processing agent. Additionally, the other volume of fluid may have a height substantially greater than the height of the volume of processing agent. The other volume of fluid may contact the volume of processing agent. The other volume of fluid may also be open to atmospheric surroundings.

In various embodiments, the method may further comprise disposing a barrier around a portion of the polycrystalline diamond material. Also, in various embodiments, the polycrystalline diamond material may comprise a polycrystalline diamond body bonded to a substrate.

In some embodiments, an assembly for processing a polycrystalline diamond body may comprise a processing container and at least one polycrystalline diamond body disposed in the processing container, the at least one polycrystalline diamond body comprising a catalyst material disposed in interstitial spaces within a polycrystalline diamond material. The assembly may also comprise a volume of processing agent disposed in the processing container, at least a portion of the polycrystalline diamond body being exposed to the volume of processing agent. The processing agent may leach at least a portion of the catalyst material from the polycrystalline diamond body. The assembly may further include a body force application portion for applying an elevated body force to the volume of processing agent while at least the portion of the polycrystalline diamond body is exposed to the volume of processing agent, and a heat application element for increasing the temperature to at least one of the volume of processing agent and at least the portion of the polycrystalline diamond body exposed to the volume of processing agent during application of the elevated body force to the volume of processing agent.

In various embodiments, the processing agent may comprise a liquid solution and the elevated body force may be sufficient to prevent a phase change of the liquid solution at the selected temperature. In some embodiments, the body force application portion may comprise a centrifugal device for rotating the processing container about a rotational axis.

In another embodiment, the body force application portion may comprise a fluid conduit containing another volume of fluid disposed gravitationally above the volume of processing agent. The fluid conduit may comprise, for example, a vertical column. The other volume of fluid may have a density greater than the density of the processing agent. Additionally, the other volume of fluid may have a height substantially greater than the height of the volume of the processing agent. In at least one embodiment, an end of the fluid conduit disposed apart from the processing container may comprise an opening such that the other volume of fluid is open to atmospheric surroundings. In at least one embodiment, a protective barrier may be disposed around a portion of the polycrystalline diamond body.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The instant disclosure is directed to leaching systems, methods and assemblies for processing superabrasive elements, such as superabrasive cutting elements, superabrasive bearings, and superabrasive discs. Such superabrasive elements may be used as cutting elements for use in a variety of applications, such as drilling tools, machining equipment, cutting tools, and other apparatuses, without limitation. Superabrasive elements, as disclosed herein, may also be used as bearing elements in a variety of bearing applications, such as thrust bearings, radial bearings, and other bearing apparatuses, without limitation.

As used herein, the terms “superabrasive” and “superhard” may refer to materials exhibiting a hardness that is at least equal to a hardness of tungsten carbide. For example, a superabrasive article may represent an article of manufacture, at least a portion of which may exhibit a hardness that is equal to or greater than the hardness of tungsten carbide. Additionally, the term “solvent,” as used herein, may refer to a single solvent compound, a mixture of two or more solvent compounds, (e.g., an alloy), and/or a mixture of one or more solvent compounds and one or more dissolved compounds. A solvent catalyst may be cobalt, nickel, iron, any Group VIII element, or any alloy or combination thereof. Moreover, the word “cutting” may refer broadly to machining processes, drilling processes, boring processes, or any other material removal process utilizing a cutting element.

FIG. 1is a perspective view of an exemplary superabrasive element10according to at least one embodiment. As illustrated inFIG. 1, superabrasive element10may comprise a superabrasive layer or table14affixed to or formed upon a substrate12. Superabrasive table14may be affixed to substrate12at interface26, which may be a planar or nonplanar interface. Superabrasive element10may comprise a rear surface18, a superabrasive face20, and a peripheral surface15. In some embodiments, peripheral surface15may include a substrate side surface16formed by substrate12and a superabrasive side surface22formed by superabrasive table14. Rear surface18may be formed by substrate12.

Superabrasive element10may also comprise a chamfer24(i.e., sloped or angled) formed by superabrasive table14. Chamfer24may comprise an angular and/or rounded edge formed at the intersection of superabrasive side surface22and superabrasive face20. Any other suitable surface shape may also be formed at the intersection of superabrasive side surface22and superabrasive face20, including, without limitation, an arcuate surface (e.g., a radius, an ovoid shape, or any other rounded shape), a sharp edge, multiple chamfers/radii, a honed edge, and/or combinations of the foregoing. At least one edge may be formed at the intersection of chamfer24and superabrasive face20and/or at the intersection of chamfer24and superabrasive side surface22. For example, cutting element10may comprise one or more cutting edges, such as an edge25and/or or an edge27. Edge25and/or or an edge27may be formed adjacent to chamfer24and may be configured to be exposed to and/or in contact with a mining formation during drilling.

In some embodiments, superabrasive element10may be utilized as a cutting element for a drill bit, in which chamfer24acts as a cutting edge. The phrase “cutting edge” may refer, without limitation, to a portion of a cutting element that is configured to be exposed to and/or in contact with a subterranean formation during drilling. In at least one embodiment, superabrasive element10may be utilized as a bearing element (e.g., with superabrasive face20acting as a bearing surface) configured to contact oppositely facing bearing elements.

According to various embodiments, superabrasive element10may also comprise a substrate chamfer formed by substrate12. For example, a chamfer comprising an angular and/or rounded edge may be formed by substrate12at the intersection of substrate side surface16and rear surface18. Any other suitable surface shape may also be formed at the intersection of substrate side surface16and rear surface18, including, without limitation, an arcuate surface (e.g., a radius, an ovoid shape, or any other rounded shape), a sharp edge, multiple chamfers/radii, a honed edge, and/or combinations of the foregoing.

Substrate12may comprise any suitable material on which superabrasive table14may be formed. In at least one embodiment, substrate12may comprise a cemented carbide material, such as a cobalt-cemented tungsten carbide material and/or any other suitable material. In some embodiments, substrate12may include a suitable metal-solvent catalyst material, such as, for example, cobalt, nickel, iron, and/or alloys thereof. Substrate12may also include any suitable material including, without limitation, cemented carbides such as titanium carbide, niobium carbide, tantalum carbide, vanadium carbide, chromium carbide, and/or combinations of any of the preceding carbides cemented with iron, nickel, cobalt, and/or alloys thereof. Superabrasive table14may be formed of any suitable superabrasive and/or superhard material or combination of materials, including, for example PCD. According to additional embodiments, superabrasive table14may comprise cubic boron nitride, silicon carbide, polycrystalline diamond, and/or mixtures or composites including one or more of the foregoing materials, without limitation.

FIG. 2is a perspective view of an exemplary superabrasive disc28according to at least one embodiment. Superabrasive disc28may be formed using any suitable technique. According to some embodiments, superabrasive disc28may comprise a PCD superabrasive table14fabricated by subjecting a plurality of diamond particles to an HPHT sintering process in the presence of a metal-solvent catalyst (e.g., cobalt, nickel, iron, or alloys thereof) to facilitate intergrowth between the diamond particles and form a PCD body comprised of bonded diamond grains that exhibit diamond-to-diamond bonding therebetween. For example, the metal-solvent catalyst may be mixed with the diamond particles, infiltrated from a metal-solvent catalyst foil or powder adjacent to the diamond particles, infiltrated from a metal-solvent catalyst present in a cemented carbide substrate, or combinations of the foregoing. The bonded diamond grains (e.g., sp3-bonded diamond grains), so-formed by HPHT sintering the diamond particles, define interstitial regions with the metal-solvent catalyst disposed within the interstitial regions of the as-sintered PCD body. The diamond particles may exhibit a selected diamond particle size distribution. Polycrystalline diamond elements, such as those disclosed in U.S. Pat. Nos. 7,866,418 and 8,297,382, the disclosure of each of which is incorporated herein, in its entirety, by this reference, may have magnetic properties in at least some regions as disclosed therein and leached regions in other regions as disclosed herein.

In some examples, superabrasive disc28may be created by first forming a superabrasive element10that includes a substrate12and a superabrasive table14, as detailed above in reference toFIG. 1. Once superabrasive element10has been produced, superabrasive table14may be separated from substrate12to form superabrasive disc28. For example, prior to or following leaching, superabrasive table14may be separated and/or finished from substrate12using any number of suitable processes, including a lapping process, a grinding process, electrical-discharge machining (e.g., wire EDM) process, and/or any other suitable material-removal process, without limitation.

The plurality of diamond particles used to form superabrasive table14comprising the PCD material may exhibit one or more selected sizes. The one or more selected sizes may be determined, for example, by passing the diamond particles through one or more sizing sieves or by any other method. In an embodiment, the plurality of diamond particles may include a relatively larger size and at least one relatively smaller size. As used herein, the phrases “relatively larger” and “relatively smaller” refer to particle sizes determined by any suitable method, which differ by at least a factor of two (e.g., 40 μm and 20 μm). More particularly, in various embodiments, the plurality of diamond particles may include a portion exhibiting a relatively larger size (e.g., 100 μm, 90 μm, 80 μm, 70 μm, 60 μm, 50 μm, 40 μm, 30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm) and another portion exhibiting at least one relatively smaller size (e.g., 30 μm, 20 μm, 15 μm, 12 μm, 10 μm, 8 μm, 4 μm, 2 μm, 1 μm, 0.5 μm, less than 0.5 μm, 0.1 μm, less than 0.1 μm). In another embodiment, the plurality of diamond particles may include a portion exhibiting a relatively larger size between about 40 μm and about 15 μm and another portion exhibiting a relatively smaller size between about 12 μm and 2 μm. Of course, the plurality of diamond particles may also include three or more different sizes (e.g., one relatively larger size and two or more relatively smaller sizes), without limitation. Different sizes of diamond particle may be disposed in different locations within a polycrystalline diamond volume, without limitation. According to at least one embodiment, disposing different sizes of diamond particles in different locations may facilitate control of a leach depth, as will be described in greater detail below.

FIG. 3Ais a cross-sectional side view of a portion of an exemplary superabrasive table14, such as the superabrasive tables14illustrated inFIGS. 1 and 2. Superabrasive table14may comprise a composite material, such as a PCD material. A PCD material may include a matrix of bonded diamond grains and interstitial regions defined between the bonded diamond grains. Such interstitial regions may be at least partially filled with various materials. In some embodiments, a metal-solvent catalyst may be disposed in at least some or a portion of the interstitial regions in superabrasive table14. Tungsten and/or tungsten carbide may also be present in at least some or a portion of the interstitial regions.

According to various embodiments, materials may be deposited in or infiltrated into interstitial regions during processing of superabrasive table14. For example, material components of substrate12may migrate into a mass of diamond particles used to form a superabrasive table14during HPHT sintering. As the mass of diamond particles is sintered, a metal-solvent catalyst may melt and flow from substrate12into the mass of diamond particles. As the metal-solvent flows into superabrasive table14, it may dissolve and/or carry additional materials, such as tungsten and/or tungsten carbide, from substrate12into the mass of diamond particles. As the metal-solvent catalyst flows into the mass of diamond particles, the metal-solvent catalyst, and any dissolved and/or undissolved materials, may at least partially fill spaces between the diamond particles. The metal-solvent catalyst may facilitate bonding of adjacent diamond particles to form a PCD layer.

Following sintering, any materials, such as, for example, the metal-solvent catalyst, tungsten, and/or tungsten carbide, may remain in interstitial regions within superabrasive table14. Such materials in the interstitial regions may reduce the thermal stability of superabrasive table14at elevated temperatures. In some examples, differences in thermal expansion coefficients between diamond grains in the as-sintered PCD body and a metal-solvent catalyst in interstitial regions between the diamond grains may weaken portions of superabrasive table14that are exposed to elevated temperatures, such as temperatures developed during drilling and/or cutting operations. The weakened portions of superabrasive table14may be excessively worn and/or damaged during the drilling and/or cutting operations.

To improve the performance, heat resistance, and/or the thermal stability of a surface of superabrasive table14, particularly in situations where the PCD material may be exposed to elevated temperatures, at least a portion of a metal-solvent catalyst, such as cobalt, may be removed from at least a portion of superabrasive table14. Additionally, tungsten and/or tungsten carbide may be removed from at least a portion of superabrasive table14. Removing a metal-solvent catalyst from the as-sintered PCD body may reduce damage to the PCD material of superabrasive table14caused by expansion of the metal-solvent catalyst. At least a portion of a metal-solvent catalyst, such as cobalt, as well as other materials, may be removed from at least a portion of the as-sintered PCD body using any suitable technique, without limitation.

For example, chemical leaching may be used to remove a metal-solvent catalyst from the as-sintered PCD body up to a depth D from a surface of superabrasive table14, as illustrated inFIG. 3A. As shown inFIG. 3A, depth D may be measured relative to an external surface of superabrasive table14, such as superabrasive face20, superabrasive side surface22, and/or chamfer24. In some examples, a metal-solvent catalyst may be removed from superabrasive table14up to a depth D from the top of the PCD to through the whole disc or to the interface. In additional examples, a metal-solvent catalyst may be removed from superabrasive table14up to a depth D of between approximately 100 and 2500 μm. The as-sintered PCD body may be leached by immersion in an acid or acid solution, such as aqua regia, nitric acid, hydrofluoric acid, or subjected to another suitable process to remove at least a portion of the metal-solvent catalyst from the interstitial regions of the PCD body and form superabrasive table14comprising a PCD table. For example, the as-sintered PCD body may be immersed in an acid solution for about 2 to about 7 days (e.g., about 3, 5, or 7 days) or for a few weeks (e.g., about 4 weeks), depending on the process employed.

In some embodiments, only selected portions of the as-sintered PCD body may be leached, leaving remaining portions of resulting superabrasive table14unleached. For example, some portions of one or more surfaces of the as-sintered PCD body may be masked or otherwise protected from exposure to a leaching agent and/or gas mixture while other portions of one or more surfaces of the as-sintered PCD body may be exposed to the leaching agent and/or gas mixture. For an example, U.S. Pat. Nos. 4,224,380 and 7,972,395, the disclosure of each of which is incorporated herein, in its entirety, by this reference, disclose leaching solutions that may be used for processing superabrasive elements as disclosed herein. Other suitable techniques may be used for removing a metal-solvent catalyst and/or other materials from the as-sintered PCD body or may be used to accelerate a chemical leaching process. For example, exposing the as-sintered PCD body to heat, pressure, electric field/current, microwave radiation, and/or ultrasound may be employed to leach or to accelerate a chemical leaching process, without limitation. Following leaching, superabrasive table14may comprise a volume of PCD material that is at least partially free or substantially free of a metal-solvent catalyst.

Following leaching, superabrasive table14may comprise a first volume30that is substantially free of a metal-solvent catalyst. However, small amounts of catalyst may remain within interstices that are inaccessible to the leaching process. First volume30may extend from one or more surfaces of superabrasive table14(e.g., superabrasive face20, superabrasive side surface22, and/or chamfer24) to a depth D from the one or more surfaces. First volume30may be located adjacent one or more surfaces of superabrasive table14.

Following leaching, superabrasive table may also comprise a second volume31that contains a metal-solvent catalyst. An amount of metal-solvent catalyst in second volume31may be substantially the same prior to and following leaching. In various embodiments, second volume31may be remote from one or more exposed surfaces of superabrasive table14. In various embodiments, an amount of metal-solvent catalyst in first volume30and/or second volume31may vary at different depths in superabrasive table14.

In at least one embodiment, superabrasive table14may include a transition region29between first volume30and second volume31. Transition region29may include amounts of metal-solvent catalyst varying between an amount of metal-solvent catalyst in first volume30and an amount of metal-solvent catalyst in second volume31. In various examples, transition region29may comprise a relatively narrow region between first volume30and second volume31.

FIG. 3Bis a cross-sectional side view of a superabrasive disc28, such as the superabrasive disc28illustrated inFIG. 2. As shown inFIG. 3B, superabrasive disc28may comprise a superabrasive table14having a superabrasive face20, a superabrasive side surface22, a rear superabrasive face23, and chamfer24. As described above in reference toFIG. 3A, a metal-solvent catalyst, as well as other materials, may be removed from at least a portion of superabrasive disc28. Accordingly, superabrasive disc28may comprise a first volume30that is substantially free of a metal-solvent catalyst and a second volume31that contains a metal-solvent catalyst. As described above, small amounts of catalyst may remain within interstices that are inaccessible to the leaching process in first volume30.

In at least one example, as shown inFIG. 3B, first volume30may extend around a substantial exterior portion of superabrasive disc28. For example, superabrasive disc28may be submerged in or exposed to a leaching agent so that superabrasive face20, superabrasive side surface22, rear superabrasive face23, and chamfers24are exposed to the leaching agent, resulting in a first volume30that extends substantially around superabrasive disc28. In some examples, only a portion of superabrasive disc28may be exposed to a leaching agent, resulting in a first volume30that extends around only a portion of superabrasive disc28.

FIG. 4is a magnified cross-sectional side view of a portion of the superabrasive table14illustrated inFIG. 3A. As shown inFIG. 4, superabrasive table14may comprise grains32and interstitial regions34between grains32defined by grain surfaces36. Grains32may comprise grains formed of any suitable superabrasive material, including, for example, diamond grains. At least some of grains32may be bonded to one or more adjacent grains32, forming a polycrystalline diamond matrix.

Interstitial material38may be disposed in at least some of interstitial regions34. Interstitial material38may comprise, for example, a metal-solvent catalyst, tungsten, and/or tungsten carbide. As shown inFIG. 4, interstitial material38may not be present in at least some of interstitial regions34. At least a portion of interstitial material38may be removed from at least some of interstitial regions34during a leaching procedure. For example, a substantial portion of interstitial material38may be removed from first volume30during a leaching procedure. Additionally, interstitial material38may remain in a second volume31following a leaching procedure.

In some examples, interstitial material38may be removed from table14to a depth that improves the performance and heat resistance of a surface of superabrasive table14to a desired degree. In some embodiments, interstitial material38may be removed from superabrasive table14to a practical limit. In order to remove interstitial material38from superabrasive table14to a depth beyond the practical limit, for example, significantly more time, temperature, and/or body force may be required. In some embodiments, interstitial material38may be removed from superabrasive table14to a practical limit where interstitial material remains in at least a portion of superabrasive table14. In various embodiments, superabrasive table14may be fully leached so that interstitial material38is substantially removed from a substantial portion of superabrasive table14. In at least one embodiment, interstitial material38may be leached from a superabrasive material, such as a PCD material in superabrasive table14, by exposing the superabrasive material to a suitable leaching agent. Interstitial material38may include a metal-solvent catalyst, such as cobalt. Relatively less concentrated and corrosive solutions may be inhibited from leaching a PCD article at a sufficient rate.

In various examples, as will be discussed in greater detail below, at least a portion of a superabrasive material and/or the leaching agent may be heated (e.g., a temperature greater than approximately 50° C.) during leaching. According to additional embodiments, at least a portion of a superabrasive material and a leaching agent may be exposed to at least one of an electric current, microwave radiation, and/or ultrasonic energy. By exposing at least a portion of a superabrasive material to an electric current, microwave radiation, and/or high frequency ultrasonic energy as the superabrasive material is exposed to a leaching agent, the rate at which the superabrasive material is leached and/or the depth to which the superabrasive material is leached may be increased.

FIG. 5is a cross-sectional side view of an exemplary superabrasive element10that is at least partially surrounded by a protective layer40according to at least one embodiment. As shown inFIG. 5, at least a portion of superabrasive element10, including substrate12, may be surrounded by protective layer40. According to various embodiments, protective layer40may comprise an inert cup, a protective coating, and/or any other suitable protective layer that inhibits or prevents a leaching agent, a cleaning agent, and/or any other desired processing agent from contacting at least a portion of the superabrasive element10. Protective layer40may prevent or inhibit a leaching agent from chemically damaging certain portions of superabrasive element10, such as, for example, substrate12, a portion of superabrasive table14, or both, during leaching. Protective layer40may be selectively formed over substrate12and/or a selected portion of superabrasive table14in any pattern, design, or as otherwise desired, without limitation. Such a configuration may provide selective leaching of superabrasive table14, which may be beneficial. Following leaching of superabrasive table14, protective layer40may be removed from superabrasive element10.

FIG. 6Ais a cross-sectional side view of an exemplary superabrasive material processing assembly50for processing a superabrasive element10according to at least one embodiment. The processing of superabrasive element10may include, for example, leaching, cleaning, and/or rinsing superabrasive element10, without limitation. A cleaning agent may include any material suitable for cleaning the leaching agent and other compounds, such as dissolved compounds including a catalyst material, from interstitial spaces in superabrasive element10after completion of the leaching process. Superabrasive element10may be exposed to the cleaning agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the cleaning agent. As shown inFIG. 6A, a superabrasive element10may be positioned within a processing container52. Processing assembly50and/or any of the other processing assembly embodiments illustrated herein may additionally or alternatively be used to leach, clean, or otherwise process any other type of superabrasive body, including, for example, PDC, a PDC insert, a superabrasive element, or a disc (e.g., superabrasive disc28illustrated inFIG. 2) that is not coupled to a substrate.

As illustrated inFIG. 6A, processing container52may have a rear wall56and a side wall54defining a cavity58. Rear wall56and side wall54may have any suitable shape, without limitation. Cavity58may contain a processing agent60that at least partially surrounds superabrasive element10such that at least a portion of superabrasive element10is exposed to processing agent60. A first volume61of processing agent60may be disposed adjacent superabrasive element10. First volume61represents a volume of fluid that is positioned adjacent to superabrasive element10and upon which a body force is exerted (e.g., due to its own mass, the mass of another fluid, and/or by any other mechanism described herein for generating and/or exerting a body force, without limitation). Superabrasive element10may be positioned in first volume61so that superabrasive element10contacts rear wall56of processing container52. In some embodiments, superabrasive element10may be positioned and/or secured within processing container52using any suitable mechanism, without limitation. Processing agent60may be a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processing superabrasive element10.

As shown inFIG. 6A, a protective layer may at least partially surround superabrasive element10to prevent processing agent60from contacting at least a portion of superabrasive element10. For example, protective layer40may surround a substrate12, while at least portions of superabrasive table14, including superabrasive face20, chamfer24, and/or superabrasive side surface22remain exposed to processing agent60. In this way, portions of superabrasive element10, such as substrate12, can be selectively inhibited or prevented from contacting processing agent60during processing. In an additional embodiment, superabrasive element10or any other suitable superabrasive body (e.g., superabrasive disc28shown inFIG. 2) may be leached with or without a protective layer disposed thereon.

In some embodiments, a body force on processing agent60and superabrasive element10may be developed through other mechanisms. For example, processing container52may be spun in a centrifuge in order to develop a body force in processing agent60and/or superabrasive element10, (as will also be described in more detail below with reference toFIGS. 7A and 7B). In additional embodiments, a second fluid having a different density than processing agent60may be placed adjacent to processing agent60in order exert a body force on processing agent60(as will be discussed in greater detail below with reference toFIGS. 9 and 10).

According to various embodiments, at least a portion of processing agent60and/or superabrasive element10may be heated during processing. For example, as illustrated inFIG. 6A, a heating element64may be disposed around at least a portion of processing container52. For example, heating element64may at least partially surround a portion of processing container52adjacent first volume61of processing agent60and/or superabrasive element10in order to generate and/or apply heat to processing agent60and/or superabrasive element10. Heating of processing agent60and/or superabrasive element10may additionally or alternatively be accomplished by any other suitable means, such as, for example, resistance-based heating, inductive heating, convection heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, within processing container52, within side wall54and/or within rear wall56of processing container52. Additionally or alternatively, processing agent60and/or superabrasive element10may be heated directly by applying an electric current and/or field or microwaves thereto, or a pre-heated processing agent60may be injected into first volume61of processing container52.

According to various embodiments, a superabrasive material may be exposed to a processing agent60, such as a leaching agent, in order to remove various materials from the interstitial regions in the superabrasive material. Certain techniques may be utilized to accelerate leaching of superabrasive element10. For example, adding heat to increase the temperature of processing agent60and/or superabrasive element10may increase the leaching efficiency and/or decrease an amount of time required to complete the leaching process. Based, for example, on the type of processing agent60used, the temperature of processing agent60and/or superabrasive element10, and how long the process is carried out, the amount of interstitial materials removed from superabrasive table14, the depth D to which the materials are removed from superabrasive table14, and/or the amount of materials remaining in the interstitial regions of superabrasive table14may be controlled.

Although increasing the temperature of processing agent60may, in some configurations, lead to accelerated leaching, leaching may be improved if processing agent60is kept from changing to a gas phase. For example, reducing or preventing phase change, and/or excessive evaporation of processing agent60may prevent loss of processing agent60and/or one or more components of processing agent60from processing container52. Preventing phase change, and/or excessive evaporation of processing agent60may also ensure consistent submersion and orientation of superabrasive element10in processing agent60. In order to prevent or reduce phase change of the processing agent60, a sufficient body force may be exerted on first volume61of processing agent60.

Optionally, as illustrated inFIG. 6B, processing assembly50may additionally include a second volume62comprising processing agent60and/or another fluid composition disposed within processing container52. For example, second volume62of processing agent60may be disposed adjacent to first volume61. Boundary line47illustrated inFIG. 6Arepresents a boundary between first volume61and second volume62. While in some embodiments, fluid compositions in processing container52may flow freely between first volume61and second volume62, first volume61represents a volume of fluid that is positioned adjacent to superabrasive element10and upon which a body force is exerted (e.g., due to its own mass, by second volume62, and/or by any other mechanism described herein for generating and/or exerting a body force, without limitation).

Second volume62of processing agent60may exert a body force on first volume61of processing agent60, thereby facilitating processing of superabrasive element10, as will be described in further detail below. In some embodiments, a body force on processing agent60and superabrasive element10may be developed through other mechanisms. For example, processing container52may be spun in a centrifuge in order to develop a body force in processing agent60and/or superabrasive element10, (as will also be described in more detail below with reference toFIGS. 7A and 7B). In additional embodiments, a second fluid having a different density than processing agent60may be placed adjacent to processing agent60in order exert a body force on processing agent60(as will be discussed in greater detail below with reference toFIGS. 9 and 10).

According to some embodiments, as illustrated inFIG. 6C, processing assembly50may additionally include a resilient seal41(e.g., a V-seal or an O-ring) surrounding at least a portion of superabrasive element10. Resilient seal41may be made of any suitable material for protecting at least a portion of superabrasive element10from processing agent60, without limitation. For example, resilient seal41may comprise an elastic polymeric material. Superabrasive element10and resilient seal41may be placed in cavity58of processing container52so that resilient seal41contacts side wall54of processing container52and surrounds at least a portion of side surface22of superabrasive table14and/or side surface16of substrate12. According to at least one embodiment, resilient seal41may be placed around superabrasive element10prior to placing superabrasive element10into cavity58of processing container52.

With resilient seal41disposed between side wall54of processing container52and side surfaces22and/or16of superabrasive element10, a sealed cavity49may be defined by resilient seal41, side surface16of substrate12, side wall54of processing container52, and rear wall56of processing container52. Processing agent60may be disposed in processing container52adjacent to superabrasive element10and resilient seal41such that processing agent60is prevented or inhibited from entering sealed cavity49. Resilient seal41may isolate substrate12and/or at least a portion of superabrasive table14from processing agent60so as to prevent and/or inhibit substrate12and/or at least a portion of superabrasive table14from contacting processing agent60. Resilient seal41may prevent or inhibit processing agent60from chemically damaging certain portions of superabrasive element10, such as, for example, substrate12, a portion of superabrasive table14, or both, during leaching. Such a configuration may further provide selective leaching of superabrasive table14.

As illustrated inFIG. 6C, resilient seal41may have a substantially V-shaped cross section. This cross section may allow resilient seal41to be compressed by processing agent60. For example, resilient seal41may be compressed by the weight and/or centrifugal force of a processing agent60causing a body force to be applied to resilient seal41in direction43. Resilient seal41may further be compressed due to an increased body force acting on processing agent60due rotation in a centrifuge, as described with respect toFIGS. 7A and 7Bbelow, or due to a second fluid exerting an added force on processing agent60as described with respect toFIGS. 9-10below. Compression of resilient seal41due to a body force applied by processing agent60may cause resilient seal41to expand between side surface16and side wall54. Such expansion may cause resilient seal41to exert an inward force against side surfaces22and/or16of superabrasive element10, thus tightening the seal around superabrasive element10and preventing or inhibiting processing agent60from contacting substrate12. While a v-shaped cross section is shown, resilient seal41may optionally have a circular cross-section, a rectangular cross-section, or any other suitable cross-sectional shape for creating a seal between superabrasive element10and side wall54of processing container52.

FIG. 7Ais a cross-sectional side view of an exemplary superabrasive material processing assembly150according to at least one embodiment. A processing assembly for processing a superabrasive element10may use high-speed rotation of processing chamber152to develop a centrifugal body force in processing agent60. For example, as shown inFIG. 7A, processing assembly150may include a centrifuge166that rotates processing containers152at high speed about rotational axis168in rotational direction Di. One or more processing containers152may be coupled to centrifuge166. For example, two processing containers152may be coupled to centrifuge166as shown inFIG. 7A.

As illustrated inFIG. 7A, each processing chamber152may have a rear wall156and a side wall154defining a cavity158within processing chamber152. Cavity158of each processing chamber152may be open to atmospheric surroundings through an opening159defined in a portion of processing chamber152that is disposed apart from superabrasive element10and/or first volume161. Cavity158may contain a processing agent60that at least partially surrounds superabrasive element10such that at least a portion of superabrasive element10is exposed to processing agent60. A first volume161of processing agent60may be disposed adjacent superabrasive element10. Additionally, optionally, a second volume162of processing agent60may be disposed within processing chamber152adjacent to first volume161at boundary line147. Superabrasive element10may be positioned in first volume161so that superabrasive element10contacts rear wall156of processing chamber152. In some embodiments, superabrasive element10may be positioned and/or secured within processing chamber152using any suitable mechanism, without limitation. Processing agent60may be a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processing superabrasive element10.

In one embodiment, at least a portion of superabrasive element10and processing agent60may be heated to a temperature that is at, close to, below, or above the temperature for phase change of processing agent60under standard conditions (e.g., standard temperature and pressure). Heating of processing agent60may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, within cavity158of processing chamber152, within side wall154and/or rear wall156of processing chamber152. Additionally or alternatively, processing agent60and/or superabrasive element10may be heated directly by applying an electric current or field thereto, or to the side wall154and/or rear wall156of processing chamber152, or a pre-heated processing agent60may be injected into first volume161of processing chamber152.

As described above, preventing phase change, and/or excessive evaporation of processing agent60may further facilitate leaching of superabrasive element10by preventing loss of processing agent60and/or one or more components of processing agent60from processing chamber152. A phase change may be prevented or inhibited by developing a sufficient centrifugal body force on first volume161of processing agent60by spinning processing chamber152within centrifuge166during processing of superabrasive element10.

Centrifuge166may be spun in rotational direction Di at a rotational frequency sufficient to exert a centrifugal body force on first volume161of processing agent60that is sufficient to prevent or inhibit processing agent60from changing phase and/or excessively evaporating at an elevated temperature. For example, in order to prevent or inhibit a phase change, and/or excessive evaporation of a processing agent60having a density that is approximately the same as water and that is heated to a temperature of approximately 200° C., a centrifuge166having a rotational radius R1of 20 cm might be spun at a rotational frequency of approximately 7,000, 8,000, 9,000, or 10,000 RPM or more, thereby subjecting first volume161to an acceleration level of approximately 14,000; 16,000; 17,000; 18,000; 19,000; 20,000 gnor more where g is 9.81 m/s2. According to at least one embodiment, rotational radius R1is measured from rotational axis168to a portion of first volume161of processing agent160.

Centrifuge166may have any suitable rotational radius R1and may be rotated at any suitable rotational frequency, without limitation. The RPM required to exert a desired centrifugal body force may vary based on the rotational radius R1of centrifuge166as well as the height and density of processing agent160. For example, a centrifuge166with a larger radius (e.g., R1) will require a lower rotational frequency (i.e., lower RPM) to produce the required centrifugal body force on the processing agent60, while a centrifuge with a smaller radius will require a higher rotational frequency (i.e., higher RPM) to produce the required force. Additionally, the centrifugal body force required to prevent or inhibit a phase change and/or excessive evaporation of processing agent60may vary depending on the phase change temperature of the particular processing agent60used. Each different processing agent60may have a different composition and/or phase change temperature when compared to other processing agents and would, therefore, require a different centrifugal body force to prevent or inhibit a phase change of the processing agent60during processing of the superabrasive element10.

According to some embodiments, as illustrated inFIG. 7B, processing assembly150may optionally include a piston element167disposed within processing chamber152adjacent to first volume161of processing agent60at boundary line147. In some embodiments, piston element167may be at least partially surrounded by a seal element169(e.g. an O-ring) to seal processing agent60within first volume161. Piston element167may exert a force on processing agent60due to high speed rotation of centrifuge166.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processing agent60may further facilitate leaching of superabrasive element10by preventing or inhibiting loss of processing agent60and/or one or more components of processing agent60from processing chamber152. A phase change may be prevented or inhibited by developing a sufficient centrifugal body force on first volume161of processing agent60by spinning processing chamber152within centrifuge166during processing of superabrasive element10. With piston element167exerting an additional force on processing agent60, a lower rotational frequency (i.e., lower RPM) may be required to produce the required centrifugal body force on processing agent60to prevent or inhibit a phase change and/or excessive evaporation of processing agent60during processing of the superabrasive element10.

WhileFIGS. 7A and 7Billustrate superabrasive element10at least partially protected from processing agent60using protective layer40, superabrasive element10may optionally be at least partially protected from contact with processing agent60using a resilient seal (e.g., resilient seal41illustrated inFIG. 6C) and/or any other suitable protection from processing agent60, without limitation.

FIG. 8is a cross-sectional side view of an exemplary superabrasive material processing assembly250according to at least one embodiment. As shown inFIG. 8, processing assembly250may include a processing container252comprising any suitable fluid conduit, such as, for example, substantially a vertical column. Side wall254and rear wall256of processing container252may define a cavity258within the processing container252. A first volume261of processing agent60may be disposed adjacent superabrasive element10and a second volume262may be disposed within processing container252adjacent to first volume261such that second volume262exerts a gravitational body force on first volume261. Second volume262may be adjacent to first volume261at boundary line247

Each of first volume261and second volume262may have heights of height H1and height H2, respectively. As shown inFIG. 8, a height H2of second volume262may be greater than a height H1of first volume261. Cavity258of processing container252may be open to atmospheric surroundings through an opening259defined in a portion of processing container252(e.g., a vertically upper end) that is disposed apart from superabrasive element10and/or first volume261. Second volume262may include processing agent60and/or may include another fluid having a density different than processing agent60. Fluid in second volume262may push gravitationally downward (i.e., in the direction G of gravitational acceleration) on first volume261so as to exert a body force on processing agent60sufficient to prevent or inhibit a phase change of processing agent60during processing of superabrasive element10.

Processing container252may have a longitudinal height accommodating a height H2of fluid that exerts a gravitational body force on first volume261of processing agent60that is sufficient to prevent or inhibit processing agent60from changing phase, and/or excessively evaporating even if it is heated. Height H2of second volume262may be significantly greater than height H1of first volume261so as to exert a sufficient body force on first volume261. For example, height H2may be one or more orders of magnitude greater than height H1.

FIG. 9is a cross-sectional side view of an exemplary superabrasive material processing assembly350according to at least one embodiment. As shown inFIG. 9, side wall354and rear wall356of processing container352may define a cavity358within the processing container352. A first volume361of processing agent60may be disposed adjacent superabrasive element10. Optionally, a second volume362may be disposed within processing container352adjacent to first volume361such that second volume362exerts a body force (e.g., gravitational and/or centrifugal) on first volume361. Second volume362may be adjacent to first volume361at boundary line347. A partial or substantial portion of second volume362may comprise a second fluid372in addition to or excluding processing agent60. Fluid in second volume362may exert a body force on processing agent60sufficient to prevent or inhibit a phase change of processing agent60during processing of superabrasive element10. Superabrasive element10may be positioned and/or secured within processing container352using any suitable mechanism, without limitation. Processing agent60may be a leaching agent, a cleaning agent, a rinsing agent, or any other suitable agent for processing a superabrasive element10. Cavity358of processing container352may be open to atmospheric surroundings through an opening359at or near the top of the processing container352.

At least a portion of superabrasive element10and processing agent60may exhibit a temperature that is close to, at, below, or above a phase change temperature of processing agent60under standard conditions (e.g., standard temperature and pressure). Heating of processing agent60may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, microwave heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, within cavity358of processing container352and/or within the walls of processing container352. Additionally or alternatively, processing agent60and/or superabrasive element10may be heated by applying an electric current or field thereto, to any of the walls of processing container352, or a pre-heated processing agent60may be injected into first volume361of processing container352.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processing agent60may further facilitate leaching and/or cleaning of superabrasive element10by preventing or inhibiting loss of processing agent60and/or one or more components of processing agent60from processing container352. Second fluid362may be disposed gravitationally above processing agent60so as to exert a sufficient gravitational body force on first volume361of processing agent60to prevent or inhibit a phase change, and/or excessive evaporation during processing of superabrasive element10.

According to some embodiments, second fluid372may have a different density (e.g., a lower density) than processing agent60and may be disposed adjacent to processing agent60in order to exert a gravitational body force on processing agent60in first volume361so as to prevent or inhibit a phase change of processing agent60during processing of superabrasive element10. Second fluid372may comprise any suitable fluid composition, without limitation. Processing agent60and second fluid372may comprise separate fluid compositions that are substantially insoluble with respect to each other in order to maintain separation between processing agent60and second fluid372. In at least one embodiment, second fluid372may act as an evaporation barrier inhibiting or preventing evaporation of processing agent60. In some embodiments, second fluid372may comprise a fluid having a density less than that of processing agent60.

Second fluid372, which may be disposed gravitationally above processing agent60inside processing container352, may exert a downward gravitational body force on processing agent60as second fluid372pushes gravitationally downward (i.e., in the direction G of gravitational acceleration) against processing agent60at fluid interface386. The amount of gravitational body force exerted on processing agent60under standard conditions (e.g., standard temperature and pressure) is related to the density of second fluid372and the height of second fluid372relative to processing agent60. Second fluid372may have a height H4that is much greater than a height H3of processing agent60so as to exert a sufficient gravitational body force on processing agent60and prevent or inhibit a phase change and/or excessive evaporation of processing agent60during processing of superabrasive element10.

FIG. 10is a cross-sectional side view of an exemplary superabrasive material processing assembly450according to at least one embodiment. As shown inFIG. 10, container walls454and divider483of processing container452may define a cavity458within processing container452. Container walls454of processing container452may define an elongated portion482, a transition portion480, and a processing portion484of processing assembly450. Elongated portion482may include an opening459at or near one end. Another end of elongated portion482may be adjacent to transition portion480. Transition portion480may extend from elongated portion482to processing portion484.

According to some embodiments, transition portion480may be bent so as to connect elongated portion482to processing portion484. Divider483may be positioned between elongated portion482and processing portion484such that processing portion484is open to elongated portion482via transition portion480. Divider483may comprise a wall and/or other feature disposed between elongated portion482and processing portion484of processing container452. Superabrasive element10and a first volume461comprising processing agent60may be disposed within processing portion484of processing container452. Superabrasive element10may be positioned and/or secured within processing container452using any suitable mechanism, without limitation. Processing agent60may comprise a leaching agent, a cleaning agent, a rinsing agent, and/or any other suitable agent for processing a superabrasive element10. Cavity458of the processing assembly450may be open to atmospheric surroundings through an opening459at the top of the processing container452. A second volume462may be disposed within elongated portion482and transition portion480. Second volume462may comprise a portion of second fluid472that is disposed gravitationally higher than first volume461comprising processing agent60. Additionally, a transition volume481may extend from second volume462to first volume461. Transition volume481may be adjacent to second volume462at boundary line449and may be adjacent to first volume461at boundary line447. At least a portion of transition volume481may comprise second fluid472. Additionally, at least a portion of transition volume481adjacent to first volume461may comprise processing agent60.

At least a portion of superabrasive element10and processing agent60may be exposed to a temperature that is close to or above a phase change temperature of processing agent60under standard conditions (e.g., standard temperature and pressure). Heating of processing agent60may be accomplished by any suitable means, such as, for example, resistance-based heating, inductive heating, microwave heating, dielectric heating, and/or combustion source heating, without limitation. Additionally, heating elements may be placed in different positions, such as, for example, within cavity458of processing container452and/or within the walls of processing container452. Additionally or alternatively, processing agent60and/or superabrasive element10may be heated by applying an electric current or field thereto, to any of the walls of processing container452, or a pre-heated processing agent60may be injected into first volume461of processing container452.

As described above, preventing or inhibiting phase change and/or excessive evaporation of processing agent60may further facilitate leaching and/or cleaning of superabrasive element10by preventing or inhibiting loss of processing agent60and/or one or more components of processing agent60from processing container452. Second fluid462may be disposed gravitationally above processing agent60so as to exert a sufficient gravitational body force on first volume461of processing agent60to prevent or inhibit a phase change and/or excessive evaporation during processing of superabrasive element10.

According to some embodiments, second fluid472may have a different density (e.g., a greater density) than processing agent60and may be disposed adjacent to first volume461. For example, second fluid472may comprise a fluid composition that is denser than processing agent60. Second fluid472may comprise any suitable fluid composition, without limitation. Processing agent60and second fluid472may comprise separate fluid compositions that are substantially insoluble with respect to each other in order to maintain separation between processing agent60and second fluid472. In at least one embodiment, second fluid472may act as an evaporation barrier inhibiting or preventing evaporation of processing agent60.

Processing assembly450may facilitate the use of a second fluid472to exert a gravitational body force on first volume461of processing agent60, particularly when second fluid472is more dense than processing agent60. For example, first volume461of processing agent60may be disposed within processing portion484of processing container452at a position that is gravitationally above an adjacent portion of second fluid472. Accordingly, while the adjacent portion second fluid472is disposed gravitationally below first volume461of processing agent60, second fluid472in elongated portion482may exert a body force on first volume461of processing agent60since second fluid472rises within elongated portion482to a height H5gravitationally above first volume461disposed in processing portion484. The body force may be exerted on first volume461of processing agent60via second fluid472of transition volume481disposed in transition portion480. The body force may be exerted by second fluid472on processing agent60as second fluid472pushes gravitationally upward (i.e., opposite the direction G of gravitational acceleration) against processing agent60(e.g., at fluid interface486when second fluid472has a greater density than processing agent60). The gravitational body force exerted on processing agent60may prevent or inhibit a phase change and/or excessive evaporation of processing agent60during processing of superabrasive element10. The amount of gravitational body force exerted on the processing agent60under standard conditions (e.g., standard temperature and pressure) may be dependent, at least in part, on the density of second fluid472and the height H5of second fluid472in elongated portion482of processing container452.

FIG. 11is a perspective view of an exemplary drill bit42according to at least one embodiment. Drill bit42may represent any type or form of earth-boring or drilling tool, including, for example, a rotary drill bit.

As illustrated inFIG. 11, drill bit42may comprise a bit body44having a longitudinal axis51. Bit body44may define a leading end structure for drilling into a subterranean formation by rotating bit body44about longitudinal axis51and applying weight to bit body44. Bit body44may include radially and longitudinally extending blades46with leading faces48and a threaded pin connection50for connecting bit body44to a drill string.

At least one cutting element57may be coupled to bit body44. For example, as shown inFIG. 11, a plurality of cutting elements57may be coupled to blades46. Cutting elements57may comprise any suitable superabrasive cutting elements, without limitation. In at least one embodiment, cutting elements57may be configured according to previously described superabrasive element10and/or superabrasive disc28. For example, each cutting element57may include a superabrasive table65, such as a PCD table, bonded to a substrate67.

Circumferentially adjacent blades46may define so-called junk slots53therebetween. Junk slots53may be configured to channel debris, such as rock or formation cuttings, away from cutting elements57during drilling. Rotary drill bit42may also include a plurality of nozzle cavities55for communicating drilling fluid from the interior of rotary drill bit42to cutting elements57.

FIG. 11depicts an example of a rotary drill bit42that employs at least one cutting element57comprising a superabrasive table65fabricated, structured, or processed in accordance with the disclosed embodiments, without limitation. Rotary drill bit42may additionally represent any number of earth-boring tools or drilling tools, including, for example, core bits, roller-cone bits, fixed-cutter bits, eccentric bits, bicenter bits, reamers, reamer wings, or any other downhole tool including superabrasive cutting elements and discs, without limitation.

The superabrasive elements and discs disclosed herein may also be utilized in applications other than cutting technology. For example, embodiments of superabrasive elements disclosed herein may also form all or part of heat sinks, wire dies, bearing elements, cutting elements, cutting inserts (e.g., on a roller cone type drill bit), machining inserts, or any other article of manufacture as known in the art. Thus, superabrasive elements and discs, as disclosed herein, may be employed in any suitable article of manufacture that includes a superabrasive element, disc, or layer. Other examples of articles of manufacture that may incorporate superabrasive elements as disclosed herein may be found in U.S. Pat. Nos. 4,811,801; 4,268,276; 4,468,138; 4,738,322; 4,913,247; 5,016,718; 5,092,687; 5,120,327; 5,135,061; 5,154,245; 5,460,233; 5,544,713; and 6,793,681, the disclosure of each of which is incorporated herein, in its entirety, by this reference.

In additional embodiments, a rotor and a stator, such as a rotor and a stator used in a thrust bearing apparatus, may each include at least one superabrasive element according to the embodiments disclosed herein. For an example, U.S. Pat. Nos. 4,410,054; 4,560,014; 5,364,192; 5,368,398; and 5,480,233, the disclosure of each of which is incorporated herein, in its entirety, by this reference, disclose subterranean drilling systems that include bearing apparatuses utilizing superabrasive elements as disclosed herein.

FIG. 12is partial cross-sectional perspective view of an exemplary thrust-bearing apparatus63according to at least one embodiment. Thrust-bearing apparatus63may utilize any of the disclosed superabrasive element embodiments (e.g., superabrasive elements processed according to the instant disclosure) as bearing elements70. Thrust-bearing apparatus63may also include bearing assemblies66. Each bearing assembly66may include a support ring68fabricated from a material, such as steel, stainless steel, or any other suitable material, without limitation.

Each support ring68may include a plurality of recesses69configured to receive corresponding bearing elements70. Each bearing element70may be mounted to a corresponding support ring68within a corresponding recess69by brazing, welding, press-fitting, using fasteners, or any another suitable mounting technique, without limitation. One or more of bearing elements70may be configured in accordance with any of the disclosed superabrasive element embodiments. For example, each bearing element70may include a substrate72and a superabrasive table74comprising a PCD material. Each superabrasive table74may form a bearing surface76.

Bearing surfaces76of one bearing assembly66may bear against opposing bearing surfaces76of a corresponding bearing assembly66in thrust-bearing apparatus63, as illustrated inFIG. 12. For example, a first bearing assembly66of thrust-bearing apparatus63may be termed a “rotor.” The rotor may be operably coupled to a rotational shaft. A second bearing assembly66of thrust-bearing apparatus63may be held substantially stationary relative to the first bearing assembly66and may be termed a “stator.”

FIG. 13is a partial cross-sectional perspective view of a radial bearing apparatus78according to another embodiment. Radial bearing apparatus78may utilize any of the disclosed superabrasive element embodiments (e.g., superabrasive elements processed according to the instant disclosure) as bearing elements84and86. Radial bearing apparatus78may include an inner race80positioned generally within an outer race82. Inner race80may include a plurality of bearing elements84affixed thereto, and outer race80may include a plurality of corresponding bearing elements86affixed thereto. One or more of bearing elements84and86may be configured in accordance with any of the superabrasive element embodiments disclosed herein.

Inner race80may be positioned generally within outer race82. Thus, inner race80and outer race82may be configured such that bearing surfaces85defined by bearing elements84and bearing surfaces87defined by bearing elements86may at least partially contact one another and move relative to one another as inner race80and outer race82rotate relative to each other. According to various embodiments, thrust-bearing apparatus63and/or radial bearing apparatus78may be incorporated into a subterranean drilling system.

FIG. 14is a partial cross-sectional perspective view of an exemplary subterranean drilling system88that includes a thrust-bearing apparatus63, as shown inFIG. 12, according to at least one embodiment. Subterranean drilling system88may include a housing90enclosing a downhole drilling motor92(i.e., a motor, turbine, or any other suitable device capable of rotating an output shaft, without limitation) that is operably connected to an output shaft94.

The thrust-bearing apparatus63shown inFIG. 12may be operably coupled to downhole drilling motor92. A rotary drill bit96, such as a rotary drill bit configured to engage a subterranean formation and drill a borehole, may be connected to output shaft94. As illustrated inFIG. 14, rotary drill bit96may be a roller cone bit comprising a plurality of roller cones98. According to additional embodiments, rotary drill bit96may comprise any suitable type of rotary drill bit, such as, for example, a so-called fixed-cutter drill bit. As a borehole is drilled using rotary drill bit96, pipe sections may be connected to subterranean drilling system88to form a drill string capable of progressively drilling the borehole to a greater depth within a subterranean formation.

A first thrust-bearing assembly66in thrust-bearing apparatus63may be configured as a rotor that is attached to output shaft94and a second thrust-bearing assembly66in thrust-bearing apparatus63may be configured as a stator. During a drilling operation using subterranean drilling system88, the rotor may rotate in conjunction with output shaft94and the stator may remain substantially stationary relative to the rotor.

According to various embodiments, drilling fluid may be circulated through downhole drilling motor92to generate torque and effect rotation of output shaft94and rotary drill bit96attached thereto so that a borehole may be drilled. A portion of the drilling fluid may also be used to lubricate opposing bearing surfaces of bearing elements70on thrust-bearing assemblies66.

FIG. 15illustrates an exemplary method1500for processing a polycrystalline diamond material according to at least one embodiment. As shown inFIG. 15, the method for processing a polycrystalline diamond material may include exposing at least a portion of the polycrystalline diamond material to a processing agent for removing at least a portion of an interstitial material from interstitial spaces within the polycrystalline diamond material (step1502).

The polycrystalline diamond material may be exposed to the processing agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the processing agent.

A polycrystalline diamond material may comprise at least a portion of any suitable polycrystalline diamond article. For example, the polycrystalline material may comprise a superabrasive table attached to a tungsten carbide substrate in a superabrasive element or a superabrasive disc (e.g., superabrasive element10and superabrasive disc28inFIGS. 1 and 2, respectively). The polycrystalline diamond material may include bonded diamond grains and interstitial regions between the bonded diamond grains (e.g., grains32and interstitial regions34inFIG. 4). Additionally, the interstitial material may be a metal-solvent catalyst, such as cobalt, nickel, iron, and/or any suitable group VIII element, may be disposed in at least some of the interstitial regions between the bonded diamond grains.

In some embodiments, the processing agent may comprise a leaching agent that removes at least a portion of an interstitial material from the polycrystalline diamond material to form a volume in the polycrystalline diamond material from which an interstitial material has been substantially removed (e.g., first volume30inFIG. 3A).

In various embodiments, the volume of processing agent may comprise a cleaning agent for cleaning the polycrystalline diamond material. Generally, such a cleaning agent may be utilized for removing an interstitial material from the polycrystalline diamond material. For example, following leaching, a leaching agent and compounds (e.g., dissolved therein) or other interstitial materials may be removed from a polycrystalline diamond material after a leaching process by exposing at least a portion of the polycrystalline diamond material to a cleaning agent. Such a cleaning agent may include any material suitable for removing the leaching agent and/or other compounds from interstitial spaces within the polycrystalline diamond material. The polycrystalline diamond material may be exposed to the cleaning agent in any suitable manner, such as, for example, by submerging at least a portion of the polycrystalline diamond material in the cleaning agent.

The method may further include applying a body force to the processing agent while at least the portion of the polycrystalline diamond material is exposed to the processing agent (step1504). The body force may be applied to the processing agent in any suitable manner. For example, a centrifugal body force may be exerted on the processing agent as the polycrystalline diamond material and processing agent are rotated at high speed in a centrifuge. Additionally, a gravitational body force may be exerted on processing agent by, for example, a second volume of fluid. The second volume of fluid may comprise, for example, the processing agent and/or another fluid composition having the same or different density than the processing agent.

The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments described herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. It is desired that the embodiments described herein be considered in all respects illustrative and not restrictive and that reference be made to the appended claims and their equivalents for determining the scope of the instant disclosure.