Polycrystalline diamond compact cutting elements, earth-boring tools including such cutting elements, and related methods of making and using such cutting elements

Abstract

A method of forming a cutting element includes sintering diamond particles in the absence of a metal solvent catalyst at a temperature of at least about 1400 DEG C and a pressure of at least about 10 GPa to form polycrystalline diamond compacts (PDCs); disposing a barrier material over at least a portion of the PDC; disposing a carbide material and a metal binder comprising at least one transition metal element over the barrier material and the PDC; and performing a second sintering process comprising sintering the carbide material, the metal binder, the barrier material, and the PDC at a temperature of at least about 1400 DEG C and a pressure of at least about 5 GPa to form the cutting element. At least a portion of the exposed outer surface of the PDC proximate to the PDC may be at least substantially free of the metallic binder.

Description

[0001] Priority declaration

[0002] This application claims the benefit of the filing date of U.S. patent application serial number 17 / 816,789, filed on August 2, 2022, for "Polycrystalline Diamond Compact Cutting Elements, Earth-Boring Tools Including Such Cutting Elements, and Related Methods of Making and Using Same," the disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to cutting elements for earth-boring tools and related earth-boring tools and methods. More specifically, the disclosed embodiments relate to techniques for producing cutting elements including thermally stable polycrystalline diamond cutting tables, and to related cutting elements and earth-boring tools. Background Art

[0004] Earth-boring tools for forming wellbores in underground formations may include a plurality of cutting elements fixed to a body. For example, a fixed-cutter earth-boring rotary drill bit (also referred to as a "scraper bit") includes a plurality of cutting elements fixedly attached to a drill bit body of the drill bit. Similarly, a roller-boring earth-boring rotary drill bit includes a roller mounted on a bearing pin extending from a leg of the drill bit body so that each roller can rotate about the bearing pin on which the roller is mounted. A plurality of cutting elements may be mounted to each roller of the drill bit.

[0005] Cutting elements for earth-boring tools typically include polycrystalline diamond compact (PDC) cutters, which are cutting elements containing polycrystalline diamond (PCD) material. Such polycrystalline diamond cutting elements are formed by sintering and bonding relatively small diamond grains or crystals together under high pressure and high temperature conditions, typically in the presence of a metal solvent catalyst (typically containing a transition metal element, such as cobalt, iron or nickel, or an alloy or mixture having such elements), to form a layer of polycrystalline diamond material on a cutting element substrate (e.g., a diamond table, a cutting table, etc.). These processes are typically referred to as high temperature / high pressure ("HPHT") processes. Catalyst materials may be mixed with the diamond grains to reduce the amount of oxidation of the diamond by oxygen and carbon dioxide during the HPHT process and to promote diamond-to-diamond bonding.

[0006] The cutting element substrate may comprise a cermet material (i.e., a particle matrix composite material comprising a hard ceramic particle phase embedded within a metal matrix phase), such as cobalt in combination with tungsten carbide. In such examples, the cobalt (or other catalyst material) in the cutting element substrate may be absorbed into the diamond grains or crystals during sintering and serve as a catalyst material for forming a diamond table from the diamond grains or crystals. In other approaches, a powdered catalyst material may be mixed with the diamond grains or crystals and then the grains or crystals are sintered together in a HPHT process.

[0007] When a diamond table is formed using an HPHT process, catalyst material may remain in the interstices between diamond grains or crystals in the resulting polycrystalline diamond table. The presence of catalyst material in the diamond table may result in thermal damage in the diamond table due to friction at the contact point between the cutting element and the formation when the cutting element is heated during use.

[0008] Conventional PDC manufacturing relies on a catalyst that migrates through the compacted diamond feed during HPHT synthesis. Conventional catalysts are cobalt-based, containing varying amounts of nickel, tungsten and chromium to promote diamond intergrowth between the compacted diamond material. However, in addition to promoting the formation of diamond-to-diamond bonds during HPHT sintering, these catalysts also disadvantageously promote the formation of graphite from diamond at elevated temperatures, such as those that occur when the cutting element is used during drilling operations. The formation of graphite in the PCD material can cause the diamond necking region (i.e., grain boundaries) to rupture due to the approximately 57% volume expansion during the transformation. This phase change is known as "reverse graphitization" or "inverse graphitization" and typically occurs at temperatures in excess of 750°C (which can be reached at and near the cutting edge of the cutting element during drilling applications). This mechanism, coupled with the mismatch in the thermal expansion coefficients and elastic moduli of the metal phase and diamond at temperatures in excess of 600°C, is believed to be a significant contributor to the degradation of a general performance criterion known as "thermal stability." From the experimental wear conditions, “reverse transformation” appears to be the main cause of impaired PCD thermal stability, promoting premature degradation of the diamond table at and near the cutting edge and, therefore, premature degradation of performance.

[0009] In order to reduce the problems associated with different thermal expansion rates and reverse transformation in polycrystalline diamond cutting elements, so-called "thermally stable" polycrystalline diamond (TSD) cutting elements have been developed. TSD cutting elements can be formed by leaching catalyst material (e.g., cobalt) from the interstices between diamond grains in a diamond table using, for example, an acid. Substantially all of the catalyst material can be removed from the diamond table, or only a portion can be removed. TSD cutting elements in which substantially all of the catalyst material has been leached from the diamond table are reported to be thermally stable at temperatures up to about 1,200°C. However, it has been determined that a fully leached diamond table is relatively more brittle and more susceptible to shear, compressive, and tensile stresses than an unleached diamond table. In an effort to provide cutting elements having a diamond table that is more thermally stable relative to an unleached diamond table, but also relatively less brittle and less susceptible to shear, compressive, and tensile stresses relative to a fully leached diamond table, cutting elements have been provided that include a diamond table in which only at least a portion of the catalyst material on the cutting face, and in some cases along the sidewalls, has been leached from the diamond table.

[0010] Thermally stable pure diamond tables formed by sintering and bonding small diamond grains under ultra-high pressure and high temperature conditions in the absence of conventional catalysts have demonstrated comparable to better cutting performance and higher thermal stability than leached diamond tables. However, the absence of any metal components in the diamond table makes it difficult to secure the pure diamond table to a support substrate and drill bit body. Pure diamond tables are also relatively more brittle and more susceptible to shear, compressive and tensile stresses than unleached diamond tables. Summary of the invention

[0011] Some embodiments of the present disclosure include a method of forming a cutting element. The method may include: performing a first sintering process, the first sintering process including sintering discrete diamond particles at a temperature of at least about 1400° C. and a pressure of at least about 10 GPa in the absence of a metal solvent catalyst to form direct diamond-to-diamond bonding between the discrete diamond particles to form a polycrystalline diamond compact; disposing a carbide material and a metal binder comprising at least one transition metal element above the polycrystalline diamond compact; and performing a second sintering process, the second sintering process including sintering the carbide material, the metal binder and the polycrystalline diamond compact at a temperature of at least about 1400° C. and a pressure of at least about 5 GPa to form a support substrate comprising the carbide material and the metal binder attached to the polycrystalline diamond compact. At least a portion of the polycrystalline diamond compact proximate to the exposed outer surface of the polycrystalline diamond compact may be at least substantially free of the metal binder.

[0012] Additional embodiments of the present disclosure include a cutting element for an earth-boring tool. The cutting element may include: a polycrystalline diamond compact comprising interbonded diamond particles having interstitial regions between the interbonded diamond particles; a support substrate comprising a carbide material and a metal binder comprising a metal-solvent catalyst sintered in situ onto the cutting table; and a barrier material located between the support substrate and the cutting table. At least a certain volume of the cutting table adjacent to an outer cutting surface of the cutting table may be at least substantially free of the metal-solvent catalyst in the interstitial region of the volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a detailed understanding of the present disclosure, reference should be made to the following detailed description in conjunction with the accompanying drawings, in which like elements are generally represented by like numerals, and in which:

[0014] Figure 1 is a simplified flow chart depicting a method of forming a cutting element according to an embodiment of the present disclosure;

[0015] FIG. 2A to FIG. 2D is Figure 1 A cross-sectional view of each action of the method of forming a cutting element;

[0016] Figure 3 is a simplified flow chart depicting a method of forming a cutting element according to additional embodiments of the present disclosure;

[0017] Figure 4A and Figure 4B is Figure 3 A cross-sectional view of each action of the method of forming a cutting element;

[0018] Figure 5 is a partially cut-away perspective view of a cutting element according to an embodiment of the present disclosure;

[0019] FIG. 6A to FIG. 6C is a simplified cross-sectional view of a cutting element according to an embodiment of the present disclosure; and

[0020] Figure 7 is a perspective view of an earth-boring tool including one or more cutting elements according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] The following description provides specific details (such as specific shapes, specific sizes, specific material compositions, and specific processing conditions) in order to provide a thorough description of the embodiments of the present disclosure. However, it will be understood by those skilled in the art that the embodiments of the present disclosure may be practiced without adopting these specific details. The embodiments of the present disclosure may be implemented in conjunction with conventional manufacturing techniques employed in the industry. In addition, the description provided below does not form a complete process flow for manufacturing cutting elements or earth-boring tools. Only those process actions and structures necessary for understanding the embodiments of the present disclosure are described in detail below. Additional actions to form a complete cutting element or a complete earth-boring tool from the structures described herein may be performed by conventional manufacturing processes.

[0022] The drawings presented herein are for illustrative purposes only and are not meant to be actual views of any particular material, assembly, structure, device or system. Changes in the shapes shown in the drawings may be expected due to, for example, manufacturing techniques and / or tolerances. Therefore, the embodiments described herein should not be understood to be limited to the specific shapes or regions illustrated, but rather include deviations in shapes, such as those caused by manufacturing. For example, a box-shaped region illustrated or described may have roughness and / or nonlinear features, and a circular region illustrated or described may include some roughness and / or linear features. In addition, the illustrated acute angles may be rounded, and vice versa. Therefore, the regions illustrated in the drawings are schematic in nature, and their shapes are not intended to illustrate the precise shapes of the regions, and do not limit the scope of the present claims. The drawings are not necessarily drawn to scale. In addition, common elements between the drawings may retain the same numerical designations.

[0023] As used herein, the singular forms following “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0024] As used herein, the term "may" with respect to a material, structure, feature, or method act indicates that this is contemplated for use in implementing an embodiment of the present disclosure, and this term is used in preference to the more restrictive term "is" in order to avoid any implication that other compatible materials, structures, features, and methods that may be used in combination therewith should or must be excluded.

[0025] As used herein, the terms "comprising," "including," "having," and their grammatical equivalents are inclusive or open-ended terms that do not exclude additional, unrecited elements or methodological actions, but also include the more restrictive terms "consisting of," and "consisting essentially of," and their grammatical equivalents.

[0026] As used herein, the term "substantially" with respect to a given parameter, characteristic, or condition refers to and includes to the extent that one of ordinary skill in the art will understand that the given parameter, characteristic, or condition is met with a certain degree of variance (such as within an acceptable tolerance). As an example, depending on a particular parameter, characteristic, or condition being substantially met, the parameter, characteristic, or condition may be at least 90.0% met, at least 95.0% met, at least 99.0% met, at least 99.9% met, or even 100.0% met.

[0027] As used herein, the term "about" used with respect to a given parameter is inclusive of the stated value and has the meaning dictated by the context (eg, it includes the degree of error associated with measurement of the given parameter, as well as variations due to manufacturing tolerances, etc.).

[0028] As used herein, the term "earth-boring tool" means and includes any type of drill bit or tool used for drilling during the formation or enlargement of a wellbore, and includes, for example, rotary drill bits, percussion drill bits, coring drill bits, eccentric drill bits, bi-center drill bits, reamers, milling cutters, drag bits, roller cone bits, hybrid drill bits, and other drill bits and tools known in the art.

[0029] As used herein, the term "polycrystalline diamond compact" refers to and includes any structure having polycrystalline diamond material that includes inter-particle bonds formed by a process involving the application of pressure (e.g., compaction) to one or more precursor materials used to form the polycrystalline diamond compact.

[0030] As used herein, the term "particle" refers to and includes any agglomeration of solid matter having an average size of about 500 μm or less. Grains (eg, crystals) and coated grains are types of particles.

[0031] As used herein, the terms "intergranular bonds" and "interbonding" refer to and include any direct atomic bonds (eg, covalent bonds, metallic bonds, etc.) between atoms in adjacent grains of a superabrasive (eg, diamond).

[0032] As used herein, the term "metal-solvent catalyst" refers to and includes transition metal elements (eg, cobalt, iron, nickel, etc.), alloys of transition metal elements, and / or mixtures thereof.

[0033] As used herein, the term "barrier material" means and includes a material that at least substantially limits the penetration (eg, diffusion) of a metal-solvent catalyst into an adjacent material.

[0034] As used herein, the term "leached" when applied to a volume of polycrystalline material (e.g., a polycrystalline diamond compact) means that the volume or at least one region of the volume does not include a substantial amount of catalyst material (e.g., a metal-solvent catalyst) in the interstices between interbonded diamond grains, regardless of whether the catalyst material is removed from the region (by a leaching process or any other removal process). Similarly, as used herein, the term "leached" means and includes the removal of catalyst material from the interstices between interbonded diamond grains of a polycrystalline diamond compact by any technique, not limited to acid leaching.

[0035] As used herein, any relational terms such as "first", "second", "front", "back", etc. are used for clarity and convenient understanding of the present disclosure and the drawings, and do not imply or depend on any particular preference or orientation unless the context clearly indicates otherwise.

[0036] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] Figure 1 A simplified flow chart illustrating a method 100 of forming a cutting element according to an embodiment of the present disclosure is depicted. As described in further detail below, the method includes: at act 102, providing a diamond powder 202; at act 104, subjecting the diamond powder 202 to a first sintering process in the absence of a metal-solvent catalyst to form a polycrystalline diamond compact (PDC); at act 106, providing a barrier material 226 over at least a portion of the PDC; at act 108, providing a precursor material 214 over the PDC and the barrier material 226; and at act 110, subjecting the PDC, the precursor material 214, and the barrier material 226 to a second sintering process to form a support substrate in situ on the PDC to form a cutting element. Because the first sintering process 104 is performed in the absence of a metal-solvent catalyst, at least a portion of the exposed outer surface of the PDC proximate the PDC does not contain a metal-solvent catalyst. The at least portion of the PDC proximate the exposed exterior surface of the PDC is thermally stabilized without having to remove (eg, leach) material from interstices of the PDC proximate the at least portion of the exposed exterior surface of the PDC. FIG. 2A to FIG. 2D In the embodiment according to the present disclosure Figure 1 The various acts of method 100 of forming a cutting element illustrate the method.

[0038] refer to Figure 2A ,refer to Figure 1At act 102 of method 100, diamond powder 202 may be disposed within a container 200, which is sometimes referred to in the industry as a barrel or cup, and which is typically composed of a metal alloy. The container 200 may at least substantially surround the diamond powder 202 and serve to hold it in place during the HPHT sintering process. As shown in FIG. 2 , the container 200 may include: an inner cup 204 in which at least a portion of the diamond powder 202 is disposed; a bottom end piece 206 in which the inner cup 204 may be at least partially disposed; and a top end piece 208 located above the diamond powder 202 and coupled (e.g., swaged) to one or more of the inner cup 204 and the bottom end piece 206. In some embodiments, the bottom end piece 206 may be omitted (e.g., not present). In some embodiments, the inner cup 204 and / or the top end piece 208 may be machined to have a desired topography. For example, the inner cup 204 and / or the top piece 208 may be machined to have a substantially non-planar topography that is complementary to a desired topography (eg, a cutting face topography) of a subsequently formed PDC.

[0039] The diamond powder 202 may be formed of and include discrete diamond particles (e.g., discrete natural diamond particles, discrete synthetic diamond particles, combinations thereof, etc.). The discrete diamond particles may individually present a desired grain size. The discrete diamond particles may include one or more of micron-sized diamond particles and nano-sized diamond particles. For example, the individual grain size of the discrete diamond particles may be in the range of about 5 nanometers (nm) to about 100 micrometers (μm), such as in the range of about 50nm to about 50μm, about 100nm to about 30μm, about 500nm to about 20μm, or about 700nm to about 10μm. In some embodiments, the grain size of the discrete diamond particles includes a collection of two or more unimodal grain size distributions. In addition, each discrete diamond particle in the discrete diamond particles may individually present a desired shape, such as at least one of a spherical, hexahedral, elliptical, cylindrical, conical, or irregular shape. In some embodiments, each of the discrete diamond particles in the diamond powder exhibits a substantially spherical shape. The discrete diamond particles may be monodisperse, wherein each discrete diamond particle exhibits substantially the same material composition, size, and shape, or may be polydisperse, wherein at least one of the discrete diamond particles exhibits one or more of a different material composition, a different particle size, and a different shape than at least another discrete diamond particle of the discrete diamond particles.

[0040] In some embodiments, the diamond powder 202 includes a temporary binder that binds discrete diamond particles together to form a green body. The green body may have any desired size, shape, and morphology corresponding to the desired size, shape, and morphology of the subsequently formed PDC. In some embodiments, the green body may be formed from multiple portions of the diamond powder 202 and the temporary binder. The multiple portions of the diamond powder 202 and the temporary binder may be arranged in any suitable manner to form the desired size, shape, and morphology of the subsequently formed PDC. The green body may be formed by any suitable method, such as, for example, an additive manufacturing process, a deposition process, a spray drying process, a vacuum drying process, a molding process, a tape casting process, or a combination thereof. Figure 1 Method 100 of forming a cutting element and / or Figure 3 During the method 300 of forming a cutting element, the temporary binder may be removed during a subsequent sintering process to which the green compact is exposed.

[0041] Next reference Figure 2B ,refer to Figure 1 In act 104, the diamond powder 202 may be subjected to an ultra-high pressure / high temperature (UHPHT) treatment (e.g., a first sintering process) to form a polycrystalline diamond compact (PDC) 210 (e.g., a cutting table). The UHPHT treatment is performed in the absence of a metal solvent catalyst (e.g., a metal binder). The UHPHT treatment may include subjecting the diamond powder 202 to an elevated temperature and elevated pressure in a direct pressurization and / or indirect heating unit for a sufficient time to transform discrete diamond particles of the diamond powder 202 into inter-bonded diamond particles. During the UHPHT treatment, the temperature within the pressurization and heating unit (e.g., the sintering temperature) may be greater than or equal to about 1400° C., such as, for example, greater than or equal to about 1500° C., greater than or equal to about 1700° C., or greater than or equal to about 1900° C. During the UHPHT treatment, the pressure within the pressurized heating unit may be greater than or equal to about 10.0 GPa, such as, for example, greater than or equal to about 12.0 GPa, greater than or equal to about 14.0 GPa, greater than or equal to about 18.0 GPa, or greater than or equal to about 20.0 GPa. The diamond powder 202 may be maintained at such temperature and pressure for a sufficient amount of time, such as a time period such as between about 30 seconds and about 1 hour, to promote mutual bonding of discrete diamond particles of the diamond powder 202. In some embodiments, the diamond powder 202 is maintained at such temperature for a time period of about 30 seconds to about 15 minutes. In some embodiments, the diamond powder 202 is maintained at such pressure for a time period of between about 5 minutes to about 30 minutes. Since the UHPHT treatment is performed in the absence of a metal-solvent catalyst, the PDC 210 does not include a metal-solvent catalyst.

[0042] After subjecting the diamond powder 202 to the UHPHT treatment, the container 200 may be removed, for example, by one or more machining processes to expose the PDC 210. The PDC 210 may be formed in the container 200 to exhibit any desired size and any desired shape. The desired size and shape of the PDC 210 may depend, at least in part, on the desired size and desired shape of a subsequently formed cutting element including the PDC 210. In some embodiments, the PDC 210 is formed to exhibit a cylindrical column shape. The PDC 210 may be formed to exhibit any desired lateral cross-sectional shape, including, but not limited to, a circular, elliptical, oval, polygonal, or irregular shape.

[0043] refer to Figure 2C , the PDC 210 may be disposed in a container 212. The container 212 and its components may be at least substantially similar to the container 200 and its components previously described with reference to FIG. Figure 1 At act 106, barrier material 226 may be disposed over at least a portion of PDC 210 within container 212. Figure 1 At act 108, the precursor material 214 may be disposed on the PDC 210 in the container 212. The container 212 may at least substantially surround and retain the PDC 210, the barrier material 226, and the precursor material 214. Figure 2C As shown, the container 212 may include an inner cup 216 in which the PDC 210, the barrier material 226, and at least a portion of the precursor material 214 may be disposed, a bottom end piece 218 in which the inner cup 216 may be at least partially disposed, and a top end piece 220 that surrounds at least a portion of the precursor material 214 and is coupled (e.g., swaged) to one or more of the inner cup 216 and the bottom end piece 218. In some embodiments, the bottom end piece 218 is omitted (e.g., not present).

[0044] The barrier material 226 may include a powder or a coating disposed between the PDC 210 and the precursor material 214. In some embodiments, the barrier material 226 is deposited on the PDC 210 and / or the precursor material 214 adjacent to an interface region between the PDC 210 and the precursor material 214. The barrier material 226 may extend between the PDC 210 and the precursor material 214 over at least a portion of a surface of the PDC 210. In some embodiments, the barrier material 226 extends at least substantially along the entire interface region between the PDC 210 and the precursor material 214. In some embodiments, the barrier material 226 may be a coating disposed on the precursor material 214. In some embodiments, the barrier material 226 is deposited on the PDC 210 and / or the precursor material 214 adjacent to the interface region between the PDC 210 and the precursor material 214 by a coating process such as, by way of non-limiting example, a thermal spray coating process, a chemical vapor deposition (CVD) process, or an electrochemical deposition process. The barrier material 226 may extend at least partially into the PDC 210 and / or the precursor material 214, thereby forming at least one transition region adjacent to the barrier material 226. The at least one transition region may include the barrier material 226 in an amount ranging from about 5 volume percent (vol%) to about 95 vol%. The barrier material 226 may at least substantially limit the penetration (e.g., diffusion) of a metal binder of the precursor material 214 into the PDC 210. In some embodiments, the barrier material 226 at least substantially prevents the penetration of a metal binder of the precursor material 214 into the PDC 210. The barrier material 226 may include one or more of tantalum, rhenium, tungsten, iridium, hafnium, niobium, molybdenum, titanium, zirconium, platinum, copper, lead, silver, and gold. In some embodiments, the barrier material 226 includes a non-catalytic material. The barrier material 226 may have a Figure 1 Method 100 of forming a cutting element and / or Figure 3 The processing temperature (eg, sintering temperature) to which the barrier material 226 is exposed during the method 300 of forming a cutting element is higher than the melting temperature.

[0045] The precursor material 214 may include a carbide material and a metal binder (e.g., a metal solvent catalyst). The precursor material 214 may include a metal binder in a range of about 5 weight percent (wt%) to about 20 wt%. In some embodiments, the metal binder is omitted (e.g., absent) from the precursor material 214. The carbide material may include, for example, one or more of tungsten carbide, titanium carbide, vanadium carbide, silicon carbide, and tantalum carbide. In some embodiments, the carbide material is tungsten carbide. In some embodiments, the metal binder includes one or more transition metal elements (e.g., iron, cobalt, nickel, manganese, etc.) and / or one or more transition metal element alloys. The precursor material 214 may include one or more of discrete carbide particles and / or sintered carbide particles, which include carbide particles bonded together by a metal binder (e.g., a cermet material). The precursor material 214 may also include one or more additional additives. In some embodiments, the precursor material 214 includes a temporary binder that binds the carbide material and the metal binder together to form a green body. The green body can have any desired size, shape, and morphology corresponding to the desired size, shape, and morphology of the subsequently formed support substrate. Figure 1 Method 100 of forming a cutting element and / or Figure 3 During the method 300 of forming a cutting element, the temporary binder may be removed during a subsequent sintering process to which the green compact is exposed.

[0046] Next reference Figure 2D ,refer to Figure 1In act 110, the PDC 210 and the precursor material 214 may be subjected to a high pressure / high temperature (HPHT) treatment (e.g., a second sintering process) to form a support substrate 224 in situ on the PDC 210. The support substrate 224 combined with the PDC 210 forms a cutting element 222. The cutting element 222 may include a barrier material 226 between the PDC 210 and the support substrate 224. The HPHT treatment may include subjecting the PDC 210, the precursor material 214, and the barrier material 226 to elevated temperatures and elevated pressures in a direct pressurization and / or indirect heating unit for a sufficient time to transform (e.g., consolidate) the precursor material 214 into the support substrate 224. During the HPHT treatment, the temperature within the pressurization and heating unit (e.g., the sintering temperature) may be greater than or equal to 1400° C., such as, for example, greater than or equal to about 1500° C., greater than or equal to about 1600° C., or greater than or equal to about 1700° C. During the HPHT treatment of the PDC 210, the barrier material 226, and the precursor material 214, the temperature within the pressurized heating unit may be lower than the temperature within the pressurized heating unit during the UHPHT treatment of the diamond powder 202. During the HPHT treatment, the pressure within the pressurized heating unit may be greater than or equal to about 5.0 GPa, such as, for example, greater than or equal to about 6.0 GPa, greater than or equal to about 7.0 GPa, or greater than or equal to about 8.0 GPa. In some embodiments, during the HPHT treatment, the pressure within the pressurized heating unit is in the range of about 5.0 GPa to about 9.0 GPa. During the HPHT treatment of the PDC 210, the barrier material 226, and the precursor material 214, the pressure within the pressurized heating unit may be lower than the pressure within the pressurized heating unit during the UHPHT treatment of the diamond powder 202. The PDC 210, barrier material 226, and precursor material 214 may be maintained at such temperature and pressure for a sufficient amount of time, such as a period of time between about 30 seconds to about 30 minutes, to promote consolidation of the precursor material 214, thereby forming the support substrate 224. In some embodiments, the PDC 210, barrier material 226, and precursor material 214 are maintained at such temperature for a period of time between about 30 seconds to about 15 minutes. In some embodiments, the PDC 210, barrier material 226, and precursor material 214 are maintained at such pressure for a period of time between about 5 minutes to about 30 minutes.

[0047] In some embodiments, during the HPHT treatment, at least a portion of the metal binder of the support substrate 224 is migrated (e.g., mass transported, diffused) into interstices in only a portion of the PDC 210 adjacent to the support substrate 224. However, because the PDC 210 is formed in the absence of a metal-solvent catalyst, at least a portion of the PDC 210 proximate the exposed outer surface of the PDC 210 does not contain a metal binder and is thermally stable without having to remove (e.g., leach) material from the interstices of the portion of the PDC 210 proximate the exposed outer surface of the PDC 210. After subjecting the PDC 210, the barrier material 226, and the precursor material 214 to the HPHT treatment, the container 212 may be removed to expose the cutting element 222, for example, by one or more machining processes.

[0048] Figure 3 A simplified flow chart illustrating a method 300 of forming a cutting element according to an embodiment of the present disclosure is depicted. As described in further detail below, the method includes: at action 302, disposing diamond powder 402; at action 304, disposing barrier material 404 above at least a portion of diamond powder 402; at action 306, disposing precursor material 406 above barrier material 404; and at action 308, subjecting diamond powder 402, barrier material 404, and precursor material 406 to a sintering process to form a support substrate in situ on a PDC with barrier material 404 located between the PDC and the support substrate. The support substrate, barrier material 404, and PDC combined together form a cutting element. Figure 4A and Figure 4B The embodiment according to the present disclosure is illustrated Figure 3 The different process acts of method 300 of forming a cutting element.

[0049] refer to Figure 4A ,refer to Figure 3 In actions 302 to 306 of method 300, diamond powder 402, barrier material 404, and precursor material 406 may be disposed within container 400. Diamond powder 402, barrier material 404, precursor material 406, and container 400 and components thereof may be at least substantially similar to those previously described with reference to FIG. 2A to FIG. 2D The diamond powder 202, barrier powder 226, precursor material 214, and container 200 and its components are shown. Barrier material 404 may be disposed over at least a portion of diamond powder 402. Precursor material 406 may be disposed over barrier material 404. In some embodiments, barrier material 404 extends at least substantially along the entire interface region between diamond powder 402 and precursor material 406.

[0050] The barrier material 404 may include a powder or a coating disposed between the diamond powder 402 and the precursor material 406. In some embodiments, the barrier material 404 may be a coating disposed on the precursor material 406. In some embodiments, the barrier material 404 is deposited on the diamond powder 402 and / or the precursor material 406 adjacent to an interface region between the diamond powder 402 and the precursor material 406 by a coating process such as, by way of non-limiting example, a thermal spray coating process, a chemical vapor deposition (CVD) process, or an electrochemical deposition process. The barrier material 404 may at least partially extend into the diamond powder 402 and / or the precursor material 406, thereby forming at least one transition region adjacent to the barrier material 404. The at least one transition region may include the barrier material 404 in an amount in a range of about 5 mass % (mass %) to about 95 mass %. The barrier material 404 may at least substantially limit the infiltration (e.g., diffusion) of the metal binder of the precursor material 406 into the diamond powder 402 and / or a subsequently formed PDC. In some embodiments, the barrier material 404 at least substantially prevents the metal binder of the precursor material 406 from infiltrating into the diamond powder 402 and / or a subsequently formed PDC.

[0051] The container 400 may at least substantially surround and retain the diamond powder 402, the barrier material 404, and the precursor material 406. Figure 4A As shown, the container 400 may include an inner cup 408 in which the diamond powder 402, the barrier material 404, and at least a portion of the precursor material 406 may be disposed, a bottom end piece 410 in which the inner cup 408 may be at least partially disposed, and a top end piece 412 surrounding at least a portion of the precursor material 406 and coupled (e.g., swaged) to one or more of the inner cup 408 and the bottom end piece 410. In some embodiments, the bottom end piece 410 is omitted (e.g., not present).

[0052] Next reference Figure 4B ,refer to Figure 3In act 308 of method 300, diamond powder 402, barrier material 404, and precursor material 406 may be subjected to UHPHT treatment (e.g., a sintering process) to form a support substrate 418 in situ on a PDC 416 (e.g., a cutting table). The support substrate 418 in combination with the PDC 416 forms the cutting element 414. The barrier material 404 may be disposed between the PDC 416 and the support substrate 418. The UHPHT treatment may include subjecting the diamond powder 402, barrier material 404, and precursor material 406 to elevated temperatures and elevated pressures in a direct pressurization and / or indirect heating unit for a sufficient time to convert discrete diamond particles of the diamond powder 402 into inter-bonded diamond particles. During the UHPHT process, the temperature (e.g., sintering temperature) within the pressurized heating unit may be greater than or equal to about 1400° C., such as, for example, greater than or equal to about 1500° C., greater than or equal to about 1700° C., or greater than or equal to about 1900° C. During the UHPHT process, the pressure within the pressurized heating unit may be greater than or equal to about 10.0 GPa, such as, for example, greater than or equal to about 12.0 GPa, greater than or equal to about 14.0 GPa, greater than or equal to about 18.0 GPa, or greater than or equal to about 20.0 GPa. The diamond powder 202 may be maintained at such temperature and pressure for a sufficient amount of time, such as a period of time between about 30 seconds to about 1 hour, to promote mutual bonding of discrete diamond particles of the diamond powder 202. In some embodiments, the diamond powder 402, the support substrate 418, and the barrier material 404 are maintained at such temperatures for a period of time between about 30 seconds to about 15 minutes. In some embodiments, the diamond powder 402, support substrate 418, and barrier material 404 are maintained at such pressure for a period of time between about 5 minutes to about 1 hour.

[0053] During UHPHT processing, the barrier material 404 may at least substantially restrict the infiltration (e.g., diffusion) of the metallic binder of the precursor material 406 into the diamond powder 402 and / or the PDC 416. In some embodiments, at least a portion of the metallic binder of the precursor material 406 and the support substrate 418 is migrated (e.g., diffused, transported) into only a portion of the PDC 416 adjacent to the support substrate 418. At least a portion of the PDC 416 proximate the exposed outer surface of the PDC 416 is at least substantially free of the metallic binder, thereby rendering the at least a portion of the PDC 416 proximate the exposed outer surface of the PDC 416 thermally stable without having to remove (e.g., leach) material from the at least a portion of the PDC 416 proximate the exposed outer surface of the PDC 416. When the metallic binder is present in the at least a portion of the PDC 416 adjacent to the support substrate 418, the at least a portion of the PDC 416 adjacent to the support substrate 418 is less susceptible to shear, compressive, and tensile stresses.

[0054] After subjecting the diamond powder 402, the barrier material 404, and the precursor material to UHPHT treatment, the container 400 may be removed, for example, by one or more machining processes to expose the cutting element 414. The PDC 416 and the support substrate 418 may be formed to exhibit any desired size and any desired shape. The desired size and shape of the PDC 416 and the support substrate 418 may depend, at least in part, on the desired size and desired shape of the cutting element 414. In some embodiments, the PDC 416 and the support substrate 418 are formed to each exhibit a cylindrical column shape.

[0055] Figure 5 A partially cutaway perspective view of a cutting element 500 according to an embodiment of the present disclosure is depicted. The cutting element 500 may be constructed according to the previously described Figures 1 to 4B The cutting element 500 is formed by at least one of the methods described. In some embodiments, the cutting table 502 is formed in the absence of a metal solvent catalyst during a UHPHT process (e.g., a first sintering process), and thereafter, the support substrate 504 is formed in situ on the cutting table 502 during a subsequent HPHT process (e.g., a second sintering process). The barrier material 514 may be disposed above the cutting table 502 (e.g., a PDC) between the UHPHT process and the subsequent HPHT process. In other embodiments, the support substrate 504 is formed on the cutting table 502 by subjecting diamond powder (e.g., discrete diamond particles) and a precursor material to a single UHPHT process (e.g., a sintering process), and the barrier material 514 is disposed between the diamond powder and the precursor material. The support substrate 504 combined with the cutting table 502 and the barrier material 514 located between the support substrate 504 and the cutting table 502 form the cutting element 500.

[0056] Cutting element 500 Figure 5 However, in some embodiments, cutting element 500 may have a different shape, such as, for example, a dome, a cone, a truncated cone, a rectangular cylinder, a pyramid, a truncated pyramid, a fin, a strut, a stud, or an irregular shape. Interface region 506 is Figure 5506 is depicted as being at least substantially planar. However, in some embodiments, the interface region 506 is at least substantially non-planar (e.g., convex, concave, ridged, sinusoidal, angled, serrated, V-shaped, U-shaped, irregularly shaped, etc.). For example, the support substrate 504 may include one or more protrusions and / or one or more recesses at the interface region 506, and the cutting table 502 may include one or more corresponding complementary recesses and / or corresponding complementary protrusions at the interface region 506. In some embodiments, the support substrate 504 includes a sidewall extending from the support substrate 504 toward an exposed cutting surface (e.g., a cutting face, a cutting edge) of the cutting table 502. The sidewall of the support substrate 504 may at least substantially surround at least a portion of the cutting table 502. In other embodiments, the cutting table 502 includes a sidewall extending from the cutting table 502 toward an exposed major surface of the support substrate 504. The sidewall of the cutting table 502 may at least substantially surround at least a portion of the support substrate 504. In some embodiments, the thickness of the cutting table 502 and / or the thickness of the supporting substrate 504 varies along the interface region 506 .

[0057] The thickness (e.g., height) extending from the exposed major surface of the support substrate 504 to the cutting face 510 of the cutting element 500 may be in the range of about 5 millimeters (mm) to about 25 mm (such as, for example, about 7 mm to about 20 mm or about 10 mm to about 15 mm). When the cutting element 500 is cylindrical, the ratio of the thickness of the cutting element 500 to the outer diameter of the cutting element 500 may be in the range of about 0.01 to about 5 (such as, for example, about 0.1 to 2). The thickness of the cutting face 510 extending from the interface region 506 to the cutting table 502 may be in the range of about 0.3 mm to about 10 mm (such as, for example, about 1 mm to about 5 mm or about 1.5 mm to about 4 mm). The thickness extending from the interface region 506 to the exposed major surface of the support substrate 504 may be in the range of about 0.7 mm to about 15 mm (such as, for example, about 1 mm to about 10 mm or about 3 mm to about 7 mm). The thickness extending from the interface region 506 to the exposed major surface of the support substrate 504 along the exposed outer edge of the support substrate can be greater than or equal to about 3 mm, such as, for example, greater than or equal to about 4 mm or greater than or equal to about 5 mm. The ratio of the thickness of the cutting table 502 to the thickness of the support substrate 504 can be in the range of about 0.05 to about 5, such as, for example, about 0.1 to 2. The ratio of the thickness of the cutting table 502 to the corresponding thickness of the support substrate 504 can vary along the interface region 506 between the cutting table 502 and the support substrate 504 in the range of about 0.05 to about 5.

[0058] The support substrate 504 may be a substrate comprising Figures 2C to 4BThe support substrate 504 is a solidified structure of the precursor materials 214 and 406. In some embodiments, the support substrate 504 is formed in situ on the cutting table 502 during the HPHT process. For example, the support substrate 504 can be a solidified structure comprising a carbide material dispersed in a metal binder. In some embodiments, the support substrate 504 does not include a metal binder. Figure 5 However, support base 504 may have any suitable shape relative to the shape of cutting element 500.

[0059] Cutting table 502 Figure 5 506, and at least one cutting edge 512 at the periphery of the cutting face 510. The surfaces of the cutting table 502 adjacent to the cutting edge 512 (e.g., at least one side surface 508, the cutting face 510) may each be substantially planar, or one or more of the surfaces of the cutting table 502 adjacent to the cutting edge 512 may be at least partially non-planar. Each of the surfaces of the cutting table 502 may be polished, or one or more of the surfaces of the cutting table 502 may be at least partially unpolished. The cutting edge 512 of the cutting table 502 may be at least partially (e.g., substantially) chamfered (e.g., beveled), at least partially (e.g., substantially) rounded (e.g., arcuate), at least partially chamfered and partially rounded, or may be non-chamfered and non-rounded. In some embodiments, the cutting edge 512 is chamfered, such as Figure 5 The cutting edge 512 may include a single chamfer or may include multiple (eg, more than one) chamfers.

[0060] The cutting table 502 is a PDC formed of inter-bonded diamond particles. In some embodiments, the cutting table 502 is formed by subjecting diamond powder to a UHPHT process in the absence of a metal solvent catalyst to convert discrete diamond particles of the diamond powder into inter-bonded diamond particles. At least a portion (e.g., at least a certain volume) of the cutting table 502 proximate an exposed outer surface of the cutting table 502 (e.g., at least one side surface 508, the cutting face 510, the cutting edge 512) is at least substantially free of a metal binder of the support substrate 504. In some embodiments, a portion of the cutting table 502 adjacent to the support substrate 504 includes at least a portion of the metal binder. In other embodiments, the entire cutting table 502 is at least substantially free of a metal binder. The at least a portion of the cutting table 502 proximate the exposed outer surface of the cutting table 502 is thermally stable without having to remove (e.g., leach) material from the at least a portion of the cutting table 502 proximate the exposed outer surface of the cutting table 502. When the metallic binder is present in the at least a portion of the cutting table 502 adjacent to the support substrate 504, the cutting table 502 is less brittle and less susceptible to shear, compressive, and tensile stresses than a conventional fully leached cutting table.

[0061] The barrier material 514 is at least substantially similar to the previously described Figures 1 to 4B The barrier materials (eg, barrier materials 226, 404) described in detail. The material type, properties, configuration, etc. of the barrier material 514 are as described above with respect to Figures 1 to 4B The barrier material 514 extends along at least a portion of the interface region 506 between the support substrate 504 and the cutting table 502. In some embodiments, the barrier material 514 extends along the entire interface region 506 between the support substrate 504 and the cutting table 502, such as Figure 5 The barrier material 514 can be at least substantially planar or at least substantially non-planar. In some embodiments, the barrier material 514 conforms to the topography of the interface region 506.

[0062] FIG. 6A to FIG. 6C Simplified cross-sectional views of cutting elements 600, 700, and 800, respectively, formed in accordance with embodiments of the present disclosure are depicted. Cutting elements 600, 700, and 800 are at least substantially similar to reference 1. Figure 5 The cutting elements 500 are described, and each includes a cutting table 602, 702, and 802 on a supporting substrate 604, 704, and 804, respectively. Unless otherwise specified, the material composition and properties of the cutting elements 600, 700, and 800 and their components are as described above for Figure 5 The cutting elements 600, 700 and 800 each include a non-planar interface region 606, 706 and 806, respectively. Figure 7 A to Figure 7 C. Cutting elements 600, 700, and 800 each include a barrier material 614, 712, and 808, respectively, located between cutting tables 602, 702, and 802 and support substrates 604, 704, and 804. Barrier materials 614, 712, and 808 are at least substantially similar to those previously described with reference to Figures 1 to 5 The barrier material (e.g., barrier material 226, 404, 516) is described above with respect to the material type, characteristics, configuration, etc. of the barrier material. Figures 1 to 5 described.

[0063] In some embodiments, the cutting table 602, 702, and 802 is formed in the absence of a metal-solvent catalyst during a UHPHT process (e.g., a first sintering process), and thereafter, a support substrate 604, 704, and 804 is formed in situ on the cutting table 602, 702, and 802 during a subsequent HPHT process (e.g., a second sintering process). A barrier material 614, 712, and 808 may be disposed above the cutting table 602, 702, and 802 (e.g., a PDC), respectively, between the UHPHT process and the subsequent HPHT process. In other embodiments, the cutting table 602, 702, and 802 and the support substrate 604, 704, and 804 are formed during a single UHPHT process (e.g., a sintering process), and include a barrier material 614, 712, and 808, respectively, located between the cutting table 602, 702, and 802 and the support substrate 604, 704, and 804. Support substrates 604, 704, and 804 in combination with cutting tables 602, 702, and 802 and barrier materials 614, 712, and 808 located between the support substrates 604, 704, and 804 and the cutting tables 602, 702, and 802 form cutting elements 600, 700, and 800, respectively.

[0064] In some embodiments, cutting stations 602, 702, and 802 are formed at least substantially similar to reference Figure 2A The container 200 is a container. The container may be made of metal or metal alloy. The container may include an inner cup, a bottom end piece and a top end piece, as described above with reference to Figure 2A The inner cup and / or the top piece may, for example, be machined to have a topography that is complementary to the desired topography of the interface region 606, 706, and 806 and / or the desired topography of the cutting table 602, 702, and 802. Thus, the cutting table 602, 702, and 802 may be formed to exhibit the desired topography during the UHPHT process. The support substrate 604, 704, and 804 formed in situ on the cutting table 602, 702, and 802, respectively, may be formed to exhibit a complementary topography during a subsequent HPHT process, thereby forming the non-planar interface region 606, 706, and 806.

[0065] In some embodiments, the cutting table 602, 702, and 802 and / or the supporting substrate 604, 704, and 804 are formed from a green body to exhibit a desired topography of the cutting table 602, 702, and 802 and / or a desired complementary topography of the supporting substrate 604, 704, and 804. Thus, the cutting table 602, 702, and 802 and the supporting substrate 604, 704, and 804 may be formed to exhibit a desired topography and / or a desired complementary topography during a UHPHT process and / or a HPHT process to form the non-planar interface region 606, 706, and 806. The barrier materials 614, 712, and 808 may be conformally formed and may exhibit a topography corresponding to the topography of the non-planar interface region 606, 706, and 806, respectively.

[0066] refer to Fig. 6A , the cutting element 600 includes a cutting table 602 attached to a support base 604. The cutting table 602 includes a protrusion 608 at least substantially surrounded by a side wall 610 of the support base 604. The side wall 610 can extend from the support base 604 toward a cutting face 612 of the cutting table 602, such as Fig. 6A The thickness of the cutting table 602 and the thickness of the supporting substrate 604 vary along the non-planar interface region 606, as shown in FIG. Fig. 6A In some embodiments, the cutting table 602 includes at least one (e.g., one or more than one) protrusion and / or at least one depression, and the support substrate includes at least one complementary corresponding depression and / or at least one complementary corresponding protrusion. The barrier material 614 can present a topography corresponding to the topography of the cutting table 602 and / or the support substrate 604.

[0067] Next reference Figure 6B , the cutting element 700 includes a cutting table 702 attached to a support base 704. The support base 704 includes a sidewall 708 that at least substantially surrounds at least a portion of the cutting table 702. The sidewall 708 can extend from the support base 704 toward a cutting face 710 of the cutting table 702, such as Figure 7 B. The thickness of the cutting table 702 and the thickness of the supporting substrate 704 vary along the non-planar interface region 706, as shown in FIG. Figure 7 B. The cutting table 702 may include at least one protrusion and / or at least one recess, and the support substrate 704 may include at least one corresponding complementary recess and / or at least one corresponding complementary protrusion. The at least one protrusion and / or the at least one recess of the cutting table 702 may be configured to interlock with the at least one corresponding complementary recess and / or the at least one corresponding complementary protrusion of the support substrate 704. The barrier material 712 may present a topography corresponding to the topography of the cutting table 702 and / or the support substrate 704.

[0068] refer to Figure 6C , the cutting element 800 includes a cutting table 802 attached to a supporting substrate 804. The thickness of the cutting table 802 and the thickness of the supporting substrate 804 vary along an interface region 806, such as Figure 7 C. The cutting table 802 may include at least one protrusion and / or at least one recess, and the support substrate 804 may include at least one corresponding complementary recess and / or at least one corresponding complementary protrusion. The at least one protrusion and / or the at least one recess of the cutting table 802 may be configured to interlock with the at least one corresponding complementary recess and / or the at least one corresponding complementary protrusion of the support substrate 804. The barrier material 808 may present a topography corresponding to the topography of the cutting table 802 and / or the support substrate 804.

[0069] Figure 7 8 is a perspective view of an earth-boring tool 900 including one or more cutting elements 902 (e.g., cutting elements 222, 414, 500, 600, 700, 800) according to the present disclosure. The earth-boring tool 900 may include a body 904 to which the cutting elements 902 may be secured. The earth-boring tool 900 specifically depicted in FIG. 8 is configured to function as a fixed cutter earth-boring drill bit including blades 906 that protrude outwardly from the remainder of the body 904 and define chip flutes 908 between adjacent rotating blades 906. In such embodiments, the cutting elements 902 may be partially secured within pockets 910 in one or more blades extending into the blades 906 (e.g., portions proximate to the blades 906 that rotate leading as primary cutting elements 902, portions that rotate following as backup cutting elements 902, or both). However, the cutting elements 902 as described herein may be incorporated into and used on other types of earth-boring tools, including, for example, roller cone drill bits, impact drill bits, coring drill bits, eccentric drill bits, bi-center drill bits, reamers, expandable reamers, milling cutters, hybrid drill bits, and other drill bits and tools known in the art.

[0070] Embodiments of the present disclosure also include:

[0071] Embodiment 1. A method of forming a cutting element, the method comprising: performing a first sintering process, the first sintering process comprising sintering discrete diamond particles at a temperature of at least about 1400° C. and a pressure of at least about 10 GPa in the absence of a metal solvent catalyst to form direct diamond-to-diamond bonds between the discrete diamond particles to form a polycrystalline diamond compact; disposing a barrier material over at least a portion of the polycrystalline diamond compact; disposing a carbide material and a metal binder comprising at least one transition metal element between the barrier material and the polycrystalline diamond compact; and performing a second sintering process, the second sintering process comprising sintering the carbide material, the metal binder, the barrier material and the polycrystalline diamond compact at a temperature of at least about 1400° C. and a pressure of at least about 5 GPa to form a support substrate comprising the carbide material and the metal binder attached to the polycrystalline diamond compact, the binder material being located between the polycrystalline diamond compact and the support substrate, wherein at least a portion of the polycrystalline diamond compact proximate an exposed outer surface of the polycrystalline diamond compact is at least substantially free of the metal binder.

[0072] Embodiment 2. A method according to Embodiment 1, wherein disposing the barrier material above at least a portion of the polycrystalline diamond compact comprises depositing the barrier material above at least the portion of the polycrystalline diamond compact by a thermal spray coating process, a chemical vapor deposition process, and / or an electrochemical deposition process.

[0073] Embodiment 3. A method according to embodiment 2, wherein the barrier material comprises one or more of tantalum, rhenium, tungsten, iridium, hafnium, niobium, molybdenum, titanium and zirconium, wherein the barrier material at least substantially prevents the catalytic binder from penetrating into the cutting table.

[0074] Embodiment 4. The method of embodiment 2, wherein the barrier material comprises a non-catalytic material comprising one or more of platinum, copper, lead, silver, and gold.

[0075] Embodiment 5. The method of any one of Embodiments 1 to 4, wherein the entire polycrystalline diamond compact is at least substantially free of the metal binder.

[0076] Embodiment 6. A method according to any one of Embodiments 1 to 4, wherein during the second sintering process, at least a portion of the metal binder infiltrates gaps in at least a portion of the polycrystalline diamond compact on a side of the polycrystalline diamond compact adjacent to the carbide material.

[0077] Embodiment 7. A method according to any one of Embodiments 1 to 6, wherein the carbide material comprises one or more of discrete carbide particles and / or sintered carbide particles, and the sintered carbide particles include carbide particles bonded together by the metal binder.

[0078] Embodiment 8. The method of any one of Embodiments 1 to 7, wherein the thickness of the polycrystalline diamond compact and the thickness of the supporting substrate vary along an interface region between the polycrystalline diamond compact and the supporting substrate.

[0079] Embodiment 9. A cutting element for an earth-boring tool, the cutting element comprising: a cutting table, the cutting table comprising a polycrystalline diamond composite sheet, the polycrystalline diamond composite sheet comprising diamond particles bonded to each other, wherein the diamond particles bonded to each other have gap regions therebetween, at least a certain volume of the cutting table adjacent to an outer cutting surface of the cutting table is at least substantially free of a metal solvent catalyst in the gap regions of the volume; a supporting substrate, the supporting substrate comprising a carbide material and a metal binder, the metal binder comprising a metal solvent catalyst sintered in situ to the cutting table; and a barrier material, the barrier material being located between the supporting substrate and the cutting table.

[0080] Embodiment 10. A cutting element according to Embodiment 9, wherein the interface region between the support substrate and the cutting table is non-planar.

[0081] Embodiment 11. A cutting element according to Embodiment 10, wherein the support substrate includes one or more protrusions at the interface region and the cutting table includes one or more corresponding complementary recesses at the interface region.

[0082] Embodiment 12. A cutting element according to any one of Embodiments 9 to 11, wherein the support substrate includes a sidewall that at least substantially surrounds at least a portion of the cutting table, or wherein the cutting table includes a sidewall that at least substantially surrounds at least a portion of the support substrate.

[0083] Embodiment 13. The cutting element of any one of Embodiments 9 to 12, wherein a ratio of a thickness of the cutting table to a thickness of the supporting substrate is in a range extending from about 0.05 to about 5.

[0084] Embodiment 14. The cutting element of any one of Embodiments 9 to 13, wherein the barrier material extends at least substantially along the entire interface region between the cutting table and the supporting substrate.

[0085] Embodiment 15. An earth-boring tool comprising: a tool body; and a cutting element according to any one of Embodiments 9 to 14, the cutting element being fixed to the tool body.

[0086] The embodiments of the present disclosure described above and illustrated in the accompanying drawings do not limit the scope of the present disclosure, which is covered by the scope of the attached claims and their legal equivalents. Any equivalent embodiments are within the scope of the present disclosure. In fact, various modifications of the present disclosure other than those shown and described herein (such as alternative useful combinations of the described elements) will be apparent to those skilled in the art from the description. Such modifications and embodiments also fall within the scope of the attached claims and equivalents.

Claims

1. A method for forming a polycrystalline diamond compact, the method comprising: performing a first sintering process, the first sintering process comprising sintering discrete diamond particles at a temperature of at least about 1400° C. and a pressure of at least about 10 GPa in the absence of a metal solvent catalyst to form direct diamond-to-diamond bonds between the discrete diamond particles to form a polycrystalline diamond compact; disposing a barrier material over at least a portion of the polycrystalline diamond compact; disposing a carbide material and a metal binder comprising at least one transition metal element over the barrier material and the polycrystalline diamond compact; as well as performing a second sintering process, the second sintering process comprising sintering the carbide material, the metal binder, the barrier material, and the polycrystalline diamond compact at a temperature of at least about 1400° C. and a pressure of at least about 5 GPa to form a support substrate comprising the carbide material and the metal binder attached to the polycrystalline diamond compact, the binder material being located between the polycrystalline diamond compact and the support substrate, Wherein at least a portion of the polycrystalline diamond compact proximate an exposed outer surface of the polycrystalline diamond compact is at least substantially free of the metal binder.

2. The method of claim 1 , wherein disposing the barrier material over at least a portion of the polycrystalline diamond compact comprises depositing the barrier material over at least the portion of the polycrystalline diamond compact by a thermal spray coating process, a chemical vapor deposition process, and / or an electrochemical deposition process.

3. The method of claim 2, wherein the barrier material comprises one or more of tantalum, rhenium, tungsten, iridium, hafnium, niobium, molybdenum, titanium, and zirconium, and wherein the barrier material at least substantially prevents the metallic binder from penetrating into the cutting table.

4. The method of claim 2, wherein the barrier material comprises a non-catalytic material comprising one or more of platinum, copper, lead, silver, and gold.

5. The method according to any one of claims 1 to 4, wherein all of the polycrystalline diamond compacts are at least substantially free of the metal binder.

6. The method according to any one of claims 1 to 4, wherein during the second sintering process, at least a portion of the metal binder infiltrates gaps in at least a portion of the polycrystalline diamond compact on a side of the polycrystalline diamond compact adjacent to the carbide material.

7. The method of any one of claims 1 to 4, wherein the carbide material comprises one or more of discrete carbide particles and / or cemented carbide particles, the cemented carbide particles comprising carbide particles bonded together by the metallic binder.

8. The method of any one of claims 1 to 4, wherein the thickness of the polycrystalline diamond compact and the thickness of the support substrate vary along an interface region between the polycrystalline diamond compact and the support substrate.

9. A cutting element for an earth-boring tool, the cutting element comprising: a cutting table comprising a polycrystalline diamond compact comprising inter-bonded diamond particles with interstitial regions therebetween, at least a volume of the cutting table adjacent an outer cutting surface of the cutting table being at least substantially free of a metal solvent catalyst in the interstitial regions of the volume; a support substrate comprising a carbide material and a metal binder comprising a metal-solvent catalyst sintered in situ onto the cutting table; and A barrier material is disposed between the support substrate and the cutting table.

10. The cutting element of claim 9, wherein an interface region between the support substrate and the cutting table is non-planar.

11. The cutting element of claim 10, wherein the support base includes one or more protrusions at the interface region and the cutting table includes one or more corresponding complementary recesses at the interface region.

12. The cutting element of any one of claims 9 to 11, wherein the support substrate comprises a sidewall at least substantially surrounding at least a portion of the cutting table, or wherein the cutting table comprises a sidewall at least substantially surrounding at least a portion of the support substrate.

13. The cutting element of any one of claims 9 to 11, wherein a ratio of a thickness of the cutting table to a thickness of the supporting substrate is within a range extending from about 0.05 to about 5.

14. The cutting element of any one of claims 9 to 11, wherein the barrier material extends at least substantially along the entire interface region between the cutting table and the support substrate.

15. An earth-boring tool, comprising: Tool body; and A cutting element according to any one of claims 9 to 11, the cutting element being fixed to the tool body.

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