METHODS OF FABRICATING A POLYCRYSTALLINE DIAMOND COMPACT INCLUDING GASEOUS LEACHING OF A POLYCRYSTALLINE DIAMOND BODY
Embodiments of the invention relate to methods of fabricating polycrystalline diamond compacts (“PDCs”) and applications for such PDCs. In an embodiment, a method of fabricating a PDC includes providing a polycrystalline diamond (“PCD”) table in which a catalyst is disposed throughout, leaching the PCD table with a gaseous leaching agent to remove catalyst from the PCD table and bonding the at least partially leached PCD table to a substrate to form a PDC.
This application is a division of U.S. application Ser. No. 13/324,237 filed on 13 Dec. 2011, the disclosure of which is incorporated herein, in its entirety, by this reference.
BACKGROUNDWear-resistant, superabrasive compacts are utilized in a variety of mechanical applications. For example, polycrystalline diamond compacts (“PDCs”) are used in drilling tools (e.g., cutting elements, gage trimmers, etc.), machining equipment, bearing apparatuses, wire-drawing machinery, and in other mechanical apparatuses.
PDCs have found particular utility as superabrasive cutting elements in rotary drill bits, such as roller cone drill bits and fixed cutter drill bits. A PDC cutting element typically includes a superabrasive diamond layer (also known as a diamond table). The diamond table is formed and bonded to a substrate using an ultra-high pressure, ultra-high temperature (“HPHT”) process. The PDC cutting element may also be brazed directly into a preformed pocket, socket, or other receptacle formed in the bit body. The substrate may be often brazed or otherwise joined to an attachment member, such as a cylindrical backing A rotary drill bit typically includes a number of PDC cutting elements affixed to the bit body. It is also known that a stud carrying the PDC may be used as a PDC cutting element when mounted to a bit body of a rotary drill bit by press-fitting, brazing, or otherwise securing the stud into a receptacle formed in the bit body.
Conventional PDCs are normally fabricated by placing a cemented-carbide substrate into a container or cartridge with a volume of diamond particles positioned adjacent to a surface of the cemented-carbide substrate. A number of such cartridges may be loaded into a HPHT press. The substrates and volume of diamond particles are then processed under HPHT conditions in the presence of a catalyst material that causes the diamond particles to bond to one another to form a matrix of bonded diamond grains defining a polycrystalline diamond (“PCD”) table. The catalyst material is often a metal-solvent catalyst, such as cobalt, nickel, iron, or alloys thereof that is used for promoting intergrowth of the diamond particles.
In one conventional approach for forming a PDC, 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. The cobalt acts as a solvent catalyst to promote intergrowth between the diamond particles, which results in formation of bonded diamond grains. A solvent catalyst may be mixed with the diamond particles prior to subjecting the diamond particles and substrate to the HPHT process.
In another conventional approach for forming a PDC, a sintered PCD table may be separately formed and then leached to remove solvent catalyst from interstitial regions between bonded diamond grains. The leached PCD table may be simultaneously HPHT bonded to a substrate and infiltrated with a non-catalyst material, such as silicon, in a separate HPHT process. The silicon may infiltrate the interstitial regions of the sintered PCD table from which the solvent catalyst has been leached and react with the diamond grains to form silicon carbide.
Despite the availability of a number of different PCD materials, manufacturers and users of PCD materials continue to seek PCD materials that exhibit improved toughness, wear resistance, and/or thermal stability.
SUMMARYEmbodiments of the invention relate to methods of fabricating PDCs and applications for such PDCs. In an embodiment, a method of fabricating a PDC includes providing a PCD table including a plurality of bonded diamond grains defining a plurality of interstitial regions in which a metal-solvent catalyst is disposed. The PCD table may then be leached with a gaseous leaching agent to at least partially remove the metal-solvent catalyst from the PCD table. The at least partially leached PCD table may then be bonded to a substrate to form the PDC.
Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings.
The drawings illustrate several embodiments of the invention, wherein identical reference numerals refer to identical elements or features in different views or embodiments shown in the drawings.
Embodiments of the invention relate to methods of fabricating PDCs and PCD tables in a manner that facilitates removal of metal-solvent catalyst used in the manufacture of PCD tables of such PDCs. The PDC embodiments disclosed herein may be used in a variety of applications, such as rotary drill bits, bearing apparatuses, wire-drawing dies, machining equipment, and other articles and apparatuses.
Referring to
The diamond particle size distribution of the plurality of diamond particles 104 may exhibit a single mode, or may be a bimodal or greater grain size distribution. In an embodiment, the diamond particles 104 may comprise 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 (by any suitable method) that differ by at least a factor of two (e.g., 30 μm and 15 μm). According to various embodiments, the diamond particles 104 may include a portion exhibiting a relatively larger average particle size (e.g., 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 average particle size (e.g., 6 μm, 5 μm, 4 μm, 3 μm, 2 μm, 1 μm, 0.5 μm, less than 0.5 μm, 0.1 μm, less than 0.1 μm). In an embodiment, the diamond particles 104 may include a portion exhibiting a relatively larger average particle size between about 10 μm and about 40 μm and another portion exhibiting a relatively smaller average particle size between about 1 μm and 4 μm. In some embodiments, the diamond particles 104 may comprise three or more different average particle sizes (e.g., one relatively larger average particle size and two or more relatively smaller average particle sizes), without limitation.
The PCD table 124, shown in
Gaseous leaching agents may be used to remove at least a portion of the catalyst from the PCD table 124. The gaseous leaching agent may be selected from at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, hydrogen gas, carbon monoxide gas, an acid gas, and mixtures thereof. For example, a gaseous leaching agent may include mixtures of a halogen gas (e.g., chlorine, fluorine, bromine, iodine, or combinations thereof) and an inert gas (e.g., argon, xenon, neon, krypton, radon, or combinations thereof). Other gaseous leaching agents include mixtures including hydrogen chloride gas, a reducing gas (e.g., carbon monoxide gas), gas from the decomposition of an ammonium salt (such as ammonium chloride which decomposes into chlorine gas, hydrogen gas and nitrogen gas), and mixtures of hydrogen gas and chlorine gas (which will form hydrogen chloride gas, in situ), acid gases such as hydrogen chloride gas, hydrochloric acid gas, hydrogen fluoride gas, and hydrofluoric acid gas. Any combination of any of the disclosed gases may be employed as the gaseous leaching agent. In an embodiment, the reaction chamber 130 may be filled with a gaseous leaching agent of about 10 volume % to about 20 volume % chlorine with the balance being argon and the gaseous leaching agent being at an elevated temperature of at least about 300° C. to about 800° C. In another embodiment, the elevated temperature may be between at least about 600° C. to about 700° C. More specifically, in another embodiment, the elevated temperature may be at least about 650° C. to about 700° C.
In an embodiment, the leaching process may take place in the reaction chamber 130 placed within a box furnace. For example, the reaction chamber 130 may be flushed at room temperature with an inert gas, such as argon. The reaction chamber 130 is heated under a flow of argon at a rate of about 10° C./min, to the desired elevated temperature. According to an embodiment, once the reaction chamber 130 reaches the desired temperature of, for example, 700° C., the gaseous leaching agent is introduced at a flow rate of 900 ml/min (measured at STP, 25° C., and 1 atm) to create the gaseous flow 132 within the reaction chamber 130 as shown in
In an embodiment, a gaseous leaching agent including at least about 0.1% to less than about 100% chlorine gas, with the balance comprised of argon gas may be used at a temperature of 700° C. and a flow rate of 900 ml/min for at least 1 hour. In an embodiment, a gaseous leaching agent comprising 20% carbon monoxide, 20% chlorine and 60% argon may be used at a temperature of 600° C. and a flow rate of 900 ml/min for at least 1 hour. In another embodiment, a gaseous leaching agent comprising 20% chlorine, 20% hydrogen chloride and 60% argon may be used at a temperature of 700° C. and a flow rate of 900 ml/min for at least 1 hour. In yet another embodiment, a gaseous leaching agent comprising 20% chlorine and 80% argon may be used at a temperature of 700° C. and a flow rate of 900 ml/min for at least 1 hour.
The assembly, shown in
In some embodiments, the PDC 210 so-formed may be subjected to a number of different shaping operations. For example, an upper working surface 212 may be planarized and/or polished. Additionally, a peripherally-extending chamfer may be formed that extends between the upper working surface 212 and a side surface of the infiltrated PCD table 214. The shaping operations include lapping, grinding, wire EDM, combinations thereof, or another suitable material-removal process.
As a result of the leaching process used to remove the catalyst, the at least partially leached PCD table 200 shown in
Referring to
In another embodiment, the at least partially leached PCD table 200 may be cleaned using an autoclave under diamond-stable conditions in which heat and pressure is applied at a temperature and pressure sufficient to sublimate at least some of the leaching by-products present in the at least partially leached PCD table 200. Suitable elevated temperature levels used in the autoclave process may range from approximately the boiling point of the leaching agent and/or the leaching by-products to three times the boiling point of the leaching agent and/or the leaching by-products. For example, in an embodiment, the elevated temperature of the autoclave process may be about 90° C. to about 350° C., such as about 175° C. to about 225° C. In other embodiments, the elevated temperature may be up to about 300° C. The pressure of the autoclave process may be selected so that diamond-stable or non-stable conditions are used, such as a pressure of about 0.5 MPa to about 3 GPa (e.g., about 1 GPa to about 2 GPa).
In another embodiment, at least some of the leaching by-products may be removed from the at least partially leached PCD table 200 using a chemical cleaning process. For example, the at least partially leached PCD table 200 may be immersed in hydrofluoric acid. The concentration of the hydrofluoric acid and the immersion time of the at least partially leached PCD table 200 in the hydrofluoric acid may be selected so that at least some of the leaching by-products and, in some embodiments, substantially all of the leaching by-products may be removed from the at least partially leached PCD table 200. In other embodiments, nitric acid, sulfuric acid, hydrochloric acid, hydrogen peroxide, phosphoric acid, perchloric acid, any combination of foregoing acids, or the like, may be selected in place of hydrofluoric acid as a chemical cleaning agent.
In an embodiment of a chemical cleaning process, at least some of the leaching by-products may be removed using an ultrasonic cleaning process. For example, the at least partially leached PCD table 200 of
In another embodiment, following removal of at least some of the leaching by-products, the second interfacial surface 204 of the at least partially leached PCD table 200 may be bonded to a substrate in an HPHT bonding process to form a PDC in the same manner as the at least partially leached PCD table 200 was bonded to form the PDC 210 shown in
Additional details about techniques for cleaning the at least partially leached PCD table 200 may be found in U.S. Pat. No. 7,845,438. U.S. Pat. No. 7,845,438 is incorporated herein, in its entirety, by this reference.
Referring to
Because the at least partially leached PCD table 300 was leached with a gaseous leaching agent and cleaned to remove at least some of the leaching by-products prior to bonding to the substrate 308, the PCD table 322 so-formed is believed to have at least one of improved thermal stability, manufacturability, or performance. In embodiments where the second interfacial surface 302 is substantially planarized, (as shown in
It should be noted that, in some embodiments, the planarization process described in
Referring to
Although not shown, the substrate 206 and selected portions of the infiltrated PCD table 214 may be masked or otherwise protected to limit unintended leaching and damage to the masked portions. In an embodiment selected portions of the infiltrated PCD table 214 may be subjected to a masking treatment to mask areas that are desired to remain unaffected by the leaching process, such as portions of the second volume 406 at and/or near the substrate 206. For example, electrodeposition or plasma deposition of a nickel alloy (e.g., a suitable Inconel® alloy), a suitable metal, or a metallic alloy covering the substrate 206 and the second volume 406 may be used to limit the leaching process to the desired directed area, the first volume 404. In other embodiments, protective leaching trays and cups for protecting portions of the infiltrated PCD table 214 and substrate 206 from leaching solution during leaching may be used. Such methods are disclosed in U.S. Patent Application No. 61/523,659 filed on 15 Aug. 2011, which is incorporated herein, in its entirety, by this reference. In another embodiment, a leaching cup made from a nickel alloy may be placed around a portion of the infiltrated PCD table 214 to serve as a shield to mask or otherwise protect a selected portion of the infiltrated PCD table 214 from the leaching process.
In an embodiment, as shown in
After leaching the infiltrated PCD table 214, the infiltrated PCD table 214 may be treated using any of the previously described cleaning processes, such as thermal or chemical cleaning, to remove some or substantially all leaching by-products therefrom from the first volume 404. It is currently believed that removing at least some of the leaching by-products from the infiltrated PCD table 214 may increase at least one of the thermal stability, manufacturability, or performance. of the leached PCD table.
Any and all of the embodiments of the PDC fabrication methods discussed herein, including the embodiments shown in
The PDCs disclosed herein may also be utilized in applications other than rotary drill bits. For example, the disclosed PDC embodiments may be used in thrust-bearing assemblies, radial bearing assemblies, wire-drawing dies, artificial joints, machining elements, PCD windows, and heat sinks
In use, the bearing surfaces 712 of one of the thrust-bearing assemblies 702 bears against the opposing bearing surfaces 712 of the other one of the bearing assemblies 702. For example, one of the thrust-bearing assemblies 702 may be operably coupled to a shaft to rotate therewith and may be termed a “rotor.” The other one of the thrust-bearing assemblies 702 may be held stationary and may be termed a “stator.”
While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting. Additionally, the words “including,” “having,” and variants thereof (e.g., “includes” and “has”) as used herein, including the claims, shall be open ended and have the same meaning as the word “comprising” and variants thereof (e.g., “comprise” and “comprises”).
Claims
1. A method, comprising:
- forming a polycrystalline diamond table having catalyst distributed therethrough;
- leaching the catalyst from at least a portion of the polycrystalline diamond table using a flow of a gaseous leaching agent;
- infiltrating the polycrystalline diamond table with a metallic infiltrant from a substrate under conditions effective to bond the infiltrated polycrystalline diamond table to the substrate to form a polycrystalline diamond compact; and
- removing at least a portion of the metallic infiltrant from the infiltrated polycrystalline diamond table of the polycrystalline diamond compact by exposing at least one working surface of the infiltrated polycrystalline diamond table to a gaseous leaching agent.
2. The method of claim 1 wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas.
3. The method of claim 1 wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof.
4. The method of claim 1, further comprising:
- prior to the act of infiltrating, heating the at least partially leached polycrystalline diamond table under partial vacuum conditions to remove at least some leaching by-products from the leached polycrystalline diamond table generated during the act of leaching.
5. The method of claim 4 wherein heating the at least partially leached polycrystalline diamond table under partial vacuum conditions comprises:
- heating the at least partially leached polycrystalline diamond table at a temperature sufficient to sublimate the at least some leaching by-products.
6. The method of claim 5 wherein the temperature is above about 500° C. and below about 700° C.
7. The method of claim 1, further comprising:
- prior to the act of infiltrating, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by chemically cleaning the leached polycrystalline diamond table.
8. The method of claim 1, further comprising:
- prior to the act of infiltrating, removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching by using an autoclave under diamond-stable conditions.
9. The method of claim 1, further comprising:
- removing at least some of the leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of removing at least a portion of the metallic infiltrant from the infiltrated polycrystalline diamond table of the polycrystalline diamond compact.
10. The method of claim 1, further comprising reducing a non-planarity of an interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant.
11. The method of claim 10 wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant comprises substantially planarizing the interfacial surface to a flatness of about 0.00050 inch to about 0.0010 inch.
12. The method of claim 10 wherein reducing a non-planarity of the interfacial surface of the at least partially leached polycrystalline diamond table prior to bonding the at least partially leached polycrystalline diamond table to the substrate occurs prior to removing at least some leaching by-products from the leached polycrystalline diamond table.
13. The method of claim 1, further comprising leaching a portion of the metallic infiltrant present in the infiltrated polycrystalline diamond table to a selected leach depth of about 50 μm to about 800 μm.
14. A method, comprising:
- forming a polycrystalline diamond table having catalyst distributed therethrough;
- leaching the catalyst from at least a portion of the polycrystalline diamond table using a gaseous leaching agent;
- infiltrating the polycrystalline diamond table with a metallic infiltrant from a substrate under conditions effective to bond the infiltrated polycrystalline diamond table to the substrate to form a polycrystalline diamond compact;
- protecting the substrate and at least a portion of the polycrystalline diamond table proximate to the substrate to limit unintended leaching; and
- leaching the metallic infiltrant from a portion of the polycrystalline diamond table to define a first volume within the polycrystalline diamond table remote from the substrate and a second volume within the polycrystalline diamond table adjacent to the substrate, wherein the first volume is substantially free of the metallic infiltrant and the second volume is substantially unaffected by the leaching.
15. The method of claim 14 wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas.
16. The method of claim 14 wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof.
17. The method of claim 14, further comprising reducing a non-planarity of an interfacial surface of the at least partially leached polycrystalline diamond table prior to infiltrating the at least partially leached polycrystalline diamond table with the metallic infiltrant.
18. A method of forming a polycrystalline diamond compact, comprising:
- placing a mass of diamond particles adjacent to a substrate including a metal-solvent catalyst therein;
- subjecting the mass of diamond particles and the substrate a high-pressure/high-temperature sintering process to form a polycrystalline diamond table with the metal-solvent distributed therethrough.
- separating the polycrystalline diamond table from the substrate;
- leaching the metal-solvent catalyst from at least a portion of the polycrystalline diamond table using a gaseous leaching agent;
- removing at least some leaching by-products from the at least partially leached polycrystalline diamond table generated during the act of leaching; and
- infiltrating the polycrystalline diamond table with a metallic infiltrant from another substrate using a high-pressure/high-temperature sintering process effective to bond the infiltrated polycrystalline diamond table to the additional substrate.
19. The method of claim 18 wherein the gaseous leaching agent includes a mixture of a halogen and at least one inert gas.
20. The method of claim 18 wherein the gaseous leaching agent includes a gas selected from the group consisting of at least one halide gas, at least one inert gas, a gas from the decomposition of an ammonium halide salt, a hydrogen gas, a reducing gas, an acid gas, a gaseous compound including halogen elements, a hydrogen chloride gas, a hydrogen fluoride gas, a nitrogen gas, and mixtures thereof.
Type: Application
Filed: Sep 22, 2014
Publication Date: Sep 15, 2016
Inventors: Julie Ann Kidd (North Ogden, UT), Michael A. Vail (Genola, UT), Kenneth E. Bertagnolli (Riverton, UT)
Application Number: 14/493,142