CUTTING ELEMENTS, EARTH-BORING TOOLS INCLUDING SUCH CUTTING ELEMENTS, AND RELATED METHODS OF MAKING AND USING SAME

TECHNICAL FIELD

This disclosure relates generally to cutting elements for earth-boring tools and related earth-boring tools and methods. More specifically, disclosed embodiments relate to techniques for producing a cutting element including a supporting substrate including a mixture of relatively larger particles and relatively smaller particles of a carbide material and to related cutting elements.

BACKGROUND

Earth boring tools for forming wellbores in subterranean earth formations may include a plurality of cutting elements secured to a body. For example, fixed cutter earth boring rotary drill bits (also referred to as “drag bits”) include a plurality of cutting elements that are fixedly attached to a bit body of the drill bit. Similarly, roller cone earth boring rotary drill bits include cones that are mounted on bearing pins extending from legs of a bit body such that each cone is capable of rotating about the bearing pin on which the cone is mounted. A plurality of cutting elements may be mounted to each cone of the drill bit.

The cutting elements used in earth boring tools often include polycrystalline diamond compact (often referred to as “PDC”) cutters, which are cutting elements that include a polycrystalline diamond (PCD) material. Such polycrystalline diamond cutting elements are formed by sintering and bonding together relatively small diamond grains or crystals under conditions of high pressure and high temperature, typically in the presence of a catalyst material (typically including a Group VIII element, such as cobalt (Co), iron (Fe), or nickel (Ni), or an alloy or mixture having such elements), to form a layer of polycrystalline diamond material (e.g., a diamond table) on a cutting element substrate. These processes are often referred to as high-pressure/high-temperature (or “HPHT”) processes. Catalyst material is typically mixed with the diamond grains to reduce the amount of oxidation of diamond by oxygen and carbon dioxide during an HPHT process and to promote diamond to diamond bonding.

The cutting element substrate may include a cermet material (i.e., a ceramic metal composite material) such as cobalt cemented tungsten carbide. In such instances, the cobalt (or other catalyst material) in the cutting element substrate may be drawn 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 methods, powdered catalyst material may be mixed with the diamond grains or crystals prior to sintering the grains or crystals together in an HPHT process.

Conventional cutting element substrates may include a carbide material, such as tungsten carbide, exhibiting a monomodal grain size distribution. The monomodal grain size distribution results in tight pore throats and an uneven pore distribution that requires an increased pressure for the catalyst material to flow through the pores to the diamond grains or crystals during an HPHT process. The increased pressure (e.g., pressure build-up) required for the catalyst material to flow during an HPHT process results in fracturing of the pore throats and eruptions of the catalyst material through the cutting element substrate and into the diamond grains or crystals. The eruptions of catalyst material result in a cutting element substrate that is heavily depleted of the catalyst material proximate the eruptions and exhibits poor durability. The eruptions of catalyst material may also result in macro-sized intrusions of the catalyst material within the diamond table, disrupting the diamond structure and decreasing the strength and quality of the diamond table.

BRIEF SUMMARY

Some embodiments of the present disclosure include a method of forming a cutting element. The method of forming a cutting element may include forming a supporting substrate comprising a homogenized binder and a mixture of coarse tungsten carbide (WC) particles and fine WC particles, depositing discrete diamond particles on the supporting substrate, and sintering the supporting substrate and the diamond particles to form a cutting table comprising inter-bonded diamond particles attached to the supporting substrate. A ratio of a particle size of the coarse WC particles to a particle size of the fine WC particles may be within a range of from about 2:1 to about 50:1. The mixture of coarse WC particles and fine WC particles may include between about 60% by volume (vol %) and 95 vol % coarse WC particles and between about 5 vol % and 40 vol % fine WC particles.

In some embodiments, the sintering of the supporting substrate includes sintering the supporting substrate at a pressure ranging from about 5 GPa to about 9 GPa.

In some embodiments, the sintering of the supporting substrate includes sintering the supporting substrate at a temperature equal to or higher than 1350° C.

In some embodiments, the coarse WC particles or the fine WC particles include cobalt cemented tungsten carbide particles.

In some embodiments, the homogenized binder includes one or more of cobalt (Co), iron (Fe), nickel (Ni) or an alloy thereof.

In some embodiments, the homogenized binder further comprises one or more additional transition metals.

In some embodiments, forming the supporting substrate further includes consolidating a precursor composition of the homogenized binder, the mixture of coarse tungsten carbide (WC) particles and fine WC particles, and a binding agent.

In some embodiments, the method further comprises removing the binding agent after consolidating the precursor composition.

In some embodiments, the consolidating of the precursor composition includes consolidating the precursor composition at a pressure ranging from about 10 MPa to about 1 GPa.

Additional embodiments include a cutting element for an earth-boring tool. The cutting element may include a supporting substrate comprising a homogenized binder and a mixture of coarse WC particles and fine WC particles, and a cutting table attached to the supporting substrate, the cutting table comprising inter-bonded diamond particles. A size of the coarse WC particles may be between about 1 μm and about 5 μm. A size of the fine WC particles may be between about 20 nm (0.02 μm) and about 2.5 μm. A ratio of an amount of the coarse WC particles to an amount of the fine WC particles in the mixture may be between about 95:5 and about 60:40 by volume.

In some embodiments, a ratio of a particle size of the coarse WC particles to a particle size of the fine WC particles is within a range extending from about 2:1 to about 50:1.

In some embodiments, the coarse WC particles or the fine WC particles include cobalt cemented tungsten carbide particles.

In some embodiments, the homogenized binder includes one or more of cobalt (Co), iron (Fe), nickel (Ni) or an alloy thereof.

In some embodiments, the homogenized binder further includes one or more additional transition metals.

In some embodiments, the supporting substrate is porous and comprises an at least substantially uniform distribution of pores connected by pore throats, the pores having a size in a range extending from about 10 nm to about 3 μm, wherein a size distribution of the pores is substantially uniform.

In some embodiments, the pores have a size in a range extending from about 10 nm to about 3 μm, and the pore throats have a size in a range extending from about 1 nm to about 3 μm.

In some embodiments, the supporting substrate is configured to exhibit a substantially uniform capillary pressure profile during a sintering process.

In some embodiments, a thickness of the cutting table is between about 5 mm and about 25 mm.

In some embodiments, a volume of the inter-bonded diamond particles comprises interstitial spaces between the inter-bonded diamond particles, the interstitial spaces comprising the homogenized binder.

In some embodiments, at least a portion of the cutting table is leached.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed understanding of the present disclosure, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements have generally been designated with like numerals, and wherein:

FIG. 1 is a micrograph of a portion of a prior art conventional cutting element;

FIGS. 2A through 2B are cross-sectional schematic views of an assembly at various acts of a method of forming a cutting element, in accordance with embodiments of the disclosure;

FIG. 3 is a partial cut-away perspective view of a schematically illustrated cutting element, in accordance with embodiments of the disclosure;

FIG. 4 is an enlarged cross-sectional schematical illustration of a portion of the cutting clement depicted in FIG. 3; and

FIG. 5 is a perspective view of a schematically illustrated earth-boring tool including one or more cutting elements, in accordance with embodiments of the disclosure.

DETAILED DESCRIPTION

The illustrations presented herein are not actual views of any particular cutting elements or earth-boring tools, but are merely idealized representations that are employed to describe example embodiments of the present disclosure. Additionally, elements common between figures may retain the same numerical designation.

The cutting elements, earth-boring tools, and methods of the present disclosure include combining relatively larger and relatively smaller particles of tungsten carbide (WC) to form a supporting substrate for a cutting element. The relatively smaller particles of WC support (e.g., prop) the relatively larger particles of WC to provide an at least substantially uniform distribution of pores and an at least substantially uniform distribution of pore throat sizes throughout the supporting substrate. The at least substantially uniform distribution of pores and the at least substantially uniform distribution of pore throat sizes provide an at least substantially uniform capillary pressure profile, allowing a binder material to uniformly flow through the supporting substrate and into a diamond powder during a sintering process to form a cutting table on the supporting substrate. Uniform flow of the binder material into the diamond powder decreases and/or prevents eruptions of the binder material through the pore throats and intrusions of the binder material into a diamond structure of the cutting table, improving the quality, wear resistance, reliability, and toughness of a cutting element formed with the supporting substrate having the mixture of relatively larger and relatively smaller particles of WC.

As used herein, the term “particle” means and includes any coherent volume of solid matter having an average dimension of about 500 μm or less. Grains (i.e., crystals) and coated grains are types of particles.

As used herein, the term “polycrystalline diamond compact” means and includes any structure including a polycrystalline diamond material including inter-granular diamond-to-diamond bonds formed by a process that involves application of pressure (e.g., compaction) to the precursor material or materials used to form the polycrystalline diamond material.

As used herein, the term “leached,” when used in relation to a volume of polycrystalline hard material (e.g., a polycrystalline diamond table), means that the volume or at least a region of the volume does not include metal-solvent catalyst material in interstitial spaces between inter-bonded diamond grains, regardless of whether or not metal-solvent catalyst material was removed from that region (by a leaching process or any other removal process). Similarly, as used herein the term “leaching” means and includes removal of a metal-solvent catalyst material from interstitial spaces between inter-bonded diamond grains of a polycrystalline diamond table by any technique, without limitation to acid leaching.

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

As used herein, the terms “comprising,” “including,” “containing,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, un-recited elements or method steps, but also include the more restrictive terms “consisting of,” “consisting essentially of,” and grammatical equivalents thereof.

As used herein, the term “may” with respect to a material, structure, feature, or method act indicates that such is contemplated for use in implementation of an embodiment of the disclosure, and such term is used in preference to the more restrictive term “is” so as to avoid any implication that other compatible materials, structures, features, and methods usable in combination therewith should or must be excluded.

As used herein, the term “configured” refers to a size, shape, material composition, and arrangement of one or more of at least one structure and at least one apparatus facilitating operation of one or more of the structure and the apparatus in a predetermined way.

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.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

As used herein, the term “substantially” in reference to a given parameter, property, or condition means and includes to a degree that one skilled in the art would understand that the given parameter, property, or condition is met with a small degree of variance, such as within acceptable manufacturing or measurement tolerances. For example, a parameter that is substantially met may be at least about 90% met, at least about 95% met, at least about 99% met, or even about 100% met.

As used herein, the term “about,” when used in reference to a given parameter, is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the given parameter).

FIG. 1 is a micrograph of a portion of a prior art conventional cutting element 10 including a supporting substrate 12 and a PDC 14. The conventional cutting element 10 comprises tungsten carbide (WC) particles exhibiting a monomodal particle size distribution. As shown in FIG. 1, the conventional cutting element 10 includes a binder eruption 12 of a solid binder material from the supporting substrate 12 into the PDC 14. The PDC 14 further includes macro-sized intrusions 18 of the solid binder material within the diamond structure of the PDC 14. The binder eruption 16 and the macro-sized intrusions 18 weaken and lower the quality, reliability, and wear resistance of the PDC 14.

FIGS. 2A and 2B depict a method of forming a cutting element 108, in accordance with embodiments of the present disclosure. As described in further detail below, the method includes forming a supporting substrate 102 including a carbide material and a homogenized metal binder, providing the supporting substrate 102 on a diamond powder 104, and subjecting the supporting substrate 102 and the diamond powder 104 to a sintering process to form a PDC 106 in situ on the supporting substrate 102 to form a cutting element 108.

The supporting substrate 102 may include a consolidated structure including particles of the carbide material dispersed within the homogenized metal binder. By way of non-limiting example, total weight of the particles of the carbide material of the consolidated structure may include from about 80% by weight (wt %) to about 95 wt % particles of the carbide material and from about 5 wt % to about 20 wt % homogenized metal binder. The consolidated structure of the supporting substrate 102 may be formed by subjecting a precursor composition to a consolidation process. The precursor composition may include the carbide material, a metal binder (e.g., metal-solvent catalyst), a binding agent, and, optionally, one or more additive(s).

The carbide material may be formed of and include discrete tungsten carbide (WC) particles. Each of the discrete WC particles may individually exhibit a desired shape, such as one or more of a spherical shape, a hexahedral shape, an ellipsoidal shape, a cylindrical shape, a conical shape, or an irregular shape. Particle (e.g., grain) sizes of the discrete WC particles may include a mixture of two or more monomodal particle size distributions. In some embodiments, particle sizes of the discrete WC particles include a mixture of two monomodal particle size distributions. The discrete WC particles may include a combination of coarse (e.g., relatively larger) WC particles and fine (e.g., relatively smaller) WC particles. The coarse WC particles may individually exhibit a particle size within a range of from about 1 μm to about 5 μm, such as, for example, within a range of from about 1 μm to about 4 μm, from about 2 μm to about 4 μm, from about 2 μm to about 3 μm, or from about 3 μm to about 4 μm, measured according to ASTM Standard E112 or international standard ISO 4499. The fine WC particles may individually exhibit a particle size within a range of from about 20 nm (0.02 μm) to about 2.5 μm, such as, for example, within a range of from about 100 nm (0.1 μm) to about 2.5 μm, from about 200 nm (0.2 μm) to about 2.3 μm, from about 500 nm (0.5 μm) to about 2 μm, from about 750 nm (0.75 μm) to about 1.5 μm, or from about 1 μm to about 2 μm, measured according to ASTM Standard E112 or international standard ISO 4499. In some embodiments, the coarse WC particles individually exhibit a particle size of about 2 μm and the fine WC particles individually exhibit a particle size of about 250 nm (0.25 μm), measured according to ASTM Standard E112 or international standard ISO 4499. In some embodiments, a ratio of the particle size of the coarse WC particles to the particle size of the fine WC particles is within a range of from about 2:1 to about 50:1, such as, for example, within a range of from about 5:1 to about 45:1, from about 10:1 to about 40:1, from about 15:1 to about 35:1, or from about 20:1 to about 30:1. In some embodiments, the ratio of the particle size of the coarse WC particles to the particle size of the fine WC particles is about 8:1. In some embodiments, the discrete WC particles may be replaced with and/or combined with discrete particles of one or more of vanadium carbide, silicon carbide, and tantalum carbide.

The discrete WC particles may include from about 60% by volume (vol %) to about 95 vol % coarse WC particles and from about 5 vol % to about 40 vol % fine WC particles. In some embodiments, the carbide material includes from about 80 vol % to about 90 vol % coarse WC particles and from about 10 vol % to about 20 vol % fine WC particles. The coarse WC particles and the fine WC particles may each be at least substantially homogeneously mixed. In other words, the coarse WC particles and the fine WC particles may be at least substantially evenly dispersed throughout the precursor composition and the subsequently formed supporting substrate 102.

The metal binder (e.g., metal-solvent catalyst) includes at least one of cobalt (Co), iron (Fe), nickel (Ni), and alloys of Co, Fe, and/or Ni. The metal binder may include one or more additional transition metal elements (e.g., manganese (Mn), rhenium (Re), chromium (Cr), etc.), one or more alloys of transition metal elements, aluminum (Al), and/or silicon (Si). In some embodiments, the metal binder includes one or more of Co and alloys containing Co, such as, for example, Co, Co—Ni, Co—Ni—Cr, Co—Cr, Co—Al—C, Co—Re—Al—C, Co—Ni—Re—Al—C, Co—Re, Co—Ru, and Co—Si. In some embodiments, the metal binder includes Re, which may form a solid solution with the discrete WC particles (e.g., W(Re)C). The metal binder may include discrete elemental particles and/or discrete alloy particles. The metal binder, and the homogenized metal binder subsequently formed from the metal binder, may be used to convert discrete diamond particles and/or diamond containing agglomerates of the diamond powder 104 into inter-bonded diamond particles to form the PDC 106.

The binding agent may comprise any material permitting the precursor composition to retain a desired shape during subsequent processing, and which may be removed (e.g., volatilized off) during the subsequent processing. By way of non-limiting example, the binding agent may comprise an organic compound, such as a wax (e.g., a paraffin wax). In some embodiments, the binding agent of the precursor composition is a paraffin wax.

The additive(s), if present, may include any material(s) formulated to impart the consolidated structure (e.g., supporting substrate) subsequently formed from the precursor composition with one or more desirable material properties (e.g., fracture toughness, strength, hardness, hardenability, wear resistance, coefficient of thermal expansions, thermal conductivity, corrosion resistance, oxidation resistance, ferromagnetism, etc.), and/or that impart a homogenized metal binder of the subsequently formed consolidated structure with a material composition facilitating the formation of a compact structure (e.g., a cutting table, such as a PDC table) having desired properties (e.g., wear resistance, impact resistance, thermal stability, etc.) using the consolidated structure. By way of non-limiting example, the additive(s) may comprise one or more elements of one or more of Group IIIA (e.g., boron (B), aluminum (Al)); Group IVA (e.g., carbon (C), silicon (Si), germanium (Ge), tin (Sn)); Group IVB (e.g., titanium (Ti), zirconium (Zr), hafnium (Hf)); Group VB (e.g., vanadium (V), niobium (Nb), tantalum (Ta)); Group VIB (e.g., chromium (Cr), molybdenum (Mo), tungsten (W)); Group VIIB (e.g., manganese (Mn)); Group VIIIB (e.g., iron (Fe), ruthenium (Ru), cobalt (Co), rhodium (Rh), iridium (Ir), nickel (Ni)); Group IB (e.g., copper (Cu), Silver (Ag), gold (Au)); and Group IIB (e.g., zinc (Zn), cadmium (Cd)) of the Periodic Table of Elements. In some embodiments, the additive(s) comprise one or more of vanadium carbide (VC), chromium carbide (Cr₃C₂), tantalum carbide (TaC), molybdenum carbide (Mo₂C), titanium carbide (TiC), and niobium carbide (NbC). The additive(s) comprising one or more of VC, Cr₃C₂, TaC, Mo₂C, TiC, and NbC may be configured to act as a grain growth inhibitor and may preserve the particle sizes of the discrete WC particles (e.g., the mixture of two or more monomodal particle size distributions). In some embodiments, the additive(s) comprise discrete particles each individually including one or more of B, Al, C, Si, Ge, Sn, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Re, Mn, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au, Zn, and Cd. In some embodiments, the additive(s) are present in the precursor composition at an amount of less than about 5 wt %.

The consolidation process may include forming the precursor composition into a green structure having a shape generally corresponding to the shape of the consolidated structure, subjecting the green structure to at least one densification process (e.g., a sintering process, a hot isostatic pressing (HIP) process, a sintered-HIP process, a hot pressing process, etc.) to form a consolidated structure including particles of the carbide material dispersed within an at least partially (e.g., substantially) homogenized metal binder, and, optionally, subjecting the consolidated structure to at least one supplemental homogenization process to further homogenize the at least partially homogenized metal binder. As used herein, the term “green” means unsintered. Accordingly, as used herein, a “green structure” means and includes an unsintered structure comprising a plurality of particles, which may be held together by interactions between one or more materials of the plurality of particles and/or another material (e.g., a binder).

The precursor composition may be formed into the green structure through conventional processes, which are not described in detail herein. For example, the precursor composition may be provided into a cavity of a container (e.g., canister, cup, etc.) having a shape complementary to a desired shape (e.g., a cylindrical column shape) of the consolidated structure, and then the precursor composition may be subjected to at least one pressing process (e.g., a cold pressing process, such as a process wherein the precursor composition is subjected to compressive pressure without substantially heating the precursor composition) to form the green structure. The pressing process may, for example, subject the precursor composition within the cavity of the container to a pressure greater than or equal to about 10 tons per square inch (tons/in²), such as within a range of from about 10 tons/in²to about 30 tons/in².

Following the formation of the green structure, the binding agent may be removed from the green structure. For example, the green structure may be dewaxed by way of vacuum or flowing hydrogen at an elevated temperature. The resulting (e.g., dewaxed) structure may then be subjected to a partial sintering (e.g., pre-sintering) process to form a brown structure having sufficient strength for the handling thereof.

Following the formation of the brown structure, the brown structure may be subjected to a densification process (e.g., a sintering process, a hot isostatic pressing (HIP) process, a sintered-HIP process, a hot pressing process, etc.) that applies sufficient heat and sufficient pressure to the brown structure to form the consolidated structure including the particles of carbide material dispersed in the at least partially homogenized metal binder. By way of non-limiting example, the brown structure may be wrapped in a sealing material (e.g., graphite foil), and may then be placed in a container made of a high temperature, self-scaling material. The container may be filled with a suitable pressure transmission medium (e.g., glass particles, ceramic particles, graphite particles, salt particles, metal particles, etc.), and the wrapped brown structure may be provided within the pressure transmission medium. The container, along with the wrapped brown structure and pressure transmission medium therein, may then be heated to a consolidation temperature facilitating the formation of the homogenized metal binder under isostatic (e.g., uniform) pressure applied by a press (e.g., a mechanical press, a hydraulic press, etc.) to at least partially (e.g., substantially) consolidate the brown structure and form the consolidated structure. The consolidation temperature may be a temperature greater than the solidus temperature of at least the components of the metal binder of the precursor composition used to form the brown structure (e.g., a temperature greater than or equal to the liquidus temperature of the components of the metal binder, a temperature between the solidus temperature and the liquidus temperature of the components of the metal binder, etc.), and the applied pressure may be greater than or equal to about 10 megapascals (MPa) (e.g., greater than or equal to about 50 MPa, greater than or equal to about 100 MPa, greater than or equal to about 250 MPa, greater than or equal to about 500 MPa, greater than or equal to about 750 MPa, greater than or equal to about 1.0 gigapascals (GPa), etc.).

As previously mentioned, following formation, the consolidated structure may be subjected to a supplemental homogenization process to further homogenize the at least partially homogenized metal binder thereof. If performed, the supplemental homogenization process may heat the consolidated structure to one or more temperatures above the liquidus temperature of the at least partially homogenized metal binder thereof for a sufficient period of time to reduce (e.g., substantially eliminate) macrosegregation within the at least partially homogenized metal binder and provide the resulting at least substantially homogenized metal binder with a single (e.g., only one) melting temperature. In some embodiments, such as in embodiments wherein the precursor composition employed to form the consolidated structure comprises discrete elemental particles (e.g., discrete elemental particles of one or more transition metal elements (e.g., Fe, Co, Ni, Mn, Re, Cr, etc.), Al, and/or Si) the at least partially homogenized metal binder of the consolidated structure may have multiple (e.g., at least two) melting temperatures following the densification process due to one or more regions of at least partially homogenized metal binder exhibiting different material composition(s) than one or more other regions of at least partially homogenized metal binder. Such different regions may, for example, form as a result of efficacy margins in source powder mixing and cold consolidation. In such embodiments, the supplemental homogenization process may substantially melt and homogenize the at least partially homogenized metal binder to remove the regions exhibiting different material composition(s) and provide the further homogenized metal binder with only one melting point. Providing the homogenized metal binder of the consolidated structure with only one melting point may be advantageous for the subsequent formation of a cutting table using the consolidated structure, as described in further detail below. In additional embodiments, such as in embodiments wherein the at least partially homogenized metal binder of the consolidated structure is already at least substantially homogeneous (e.g., does not include regions exhibiting different material composition(s) than other regions thereof) following the densification process, the supplemental homogenization process may be omitted.

The supporting substrate 102 may be formed to exhibit any desired dimensions and any desired shape. The dimensions and shape of the supporting substrate 102 may at least partially depend upon desired dimensions and desired shapes of a compact structure (e.g., a cutting table, such as the PDC 106) to subsequently be formed on and/or attached to the supporting substrate 102, as described in further detail below. In some embodiments, the supporting substrate 102 is formed to exhibit a cylindrical column shape. In additional embodiments, the supporting substrate 102 is formed to exhibit a different shape, such as a dome shape, a conical shape, a frusto-conical shape, a rectangular column shape, a pyramidal shape, a frusto pyramidal shape, a fin shape, a pillar shape, a stud shape, or an irregular shape. Accordingly, the supporting substrate 102 may be formed to exhibit any desired lateral cross-sectional shape including, but not limited to, a circular shape, a semicircular shape, an ovular shape, a tetragonal shape (e.g., square, rectangular, trapezium, trapezoidal, parallelogram, etc.), a triangular shape, an elliptical shape, or an irregular shape.

The supporting substrate 102 includes the discrete WC particles having particle sizes including a mixture of two or more monomodal particle size distributions. The fine WC particles and the coarse WC particles of the discrete WC particles may each be at least substantially evenly (e.g., homogeneously) distributed within the homogenized metal binder of the supporting substrate 102. The fine WC particles may support (e.g., prop) the coarse WC particles to provide an at least substantially uniform distribution of pores (e.g., interstitial spaces, capillaries) and an at least substantially uniform distribution pore throat sizes throughout the supporting substrate 102. The supporting substrate 102 may exhibit an at least substantially uniform capillary pressure profile across the entirety of the supporting substrate 102 due to the at least substantially uniform distribution of pores and the at least substantially uniform distribution of pore throat sizes. By way of non-limiting example, the pores may exhibit a size (e.g., a diameter of a sphere that can fit within the pore) within a range of from about 10 nm (0.01 μm) to about 3 μm, such as, for example, from about 50 nm (0.05 μm) to about 2.75 μm, from about 100 nm (0.1 μm) to about 2.5 μm, from about 500 nm (0.5 μm) to about 2.25 μm, from about 750 μm (0.75 μm) to about 2 μm, or from about 1 μm to about 1.5 μm. By way of non-limiting example, the pore throats of the pores may exhibit a size (e.g., a diameter of a circle perpendicular to a fluid flow direction out of the tightest spot in the pore) within a range of from about 1 nm (0.001 μm) to about 3 μm, such as, for example, from about 10 nm (0.01 μm) to about 2.75 μm, from about 50 nm (0.05 μm) to about 2.5 μm, from about 100 nm (0.1 μm) to about 2.25 μm, from about 500 nm (0.5 μm) to about 2 μm, from about 750 nm (0.75 μm) to about 1.5 μm, or from about 1 μm to about 1.5 μm. Since the fine WC particles support the coarse WC particles, a distribution of pore throat sizes between the discrete WC particles of the supporting substrate 102 may be relatively smaller (e.g., thinner, less wide) and more uniform (e.g., balanced, symmetrical) than a distribution of pore throat sizes observed in conventional supporting substrates formed of carbide particles exhibiting a monomodal size distribution. Furthermore, sizes of the smallest pore throats of the pores between the discrete WC particles of the supporting substrate 102 may be relatively larger than the smallest pore throat sizes observed in conventional supporting substrates formed of carbide particles exhibiting a monomodal size distribution. The homogenized metal binder within the pores between the discrete WC particles may be at least substantially evenly (e.g., homogenously) distributed throughout the entirety of the supporting substrate 102. The at least substantially uniform capillary pressure profile of the supporting substrate 102 enables the homogenized metal binder having any desired composition to uniformly flow into the diamond powder 104 during formation of the cutting element 108.

Referring to FIG. 2A, the diamond powder 104 may be provided within a container 110, sometimes referred to in the industry as a cartridge or a cup, that is typically comprised of a metal alloy. The supporting substrate 102 may be provided on the diamond powder 104 within the container 110. In some embodiments, the supporting substrate 102 is provided directly on the diamond powder 104. The container 110 may at least substantially surround and is used to hold the diamond powder 104 and the supporting substrate 102 in position during an HPHT sintering process. As shown in FIG. 2A, the container 110 may include an inner cup 112 in which the diamond powder 104 and at least a portion of the supporting substrate 102 is disposed, a bottom end piece 114 in which the inner cup 112 may be at least partially disposed, and a top end piece 116 over and at least partially surrounding the supporting substrate 102 and coupled (e.g., swage bonded) to one or more of the inner cup 112 and the bottom end piece 114. In some embodiments, the bottom end piece 114 is omitted (e.g., absent).

The diamond powder 104 may be formed of and include discrete diamond particles (e.g., discrete natural diamond particles, discrete synthetic diamond particles, combinations thereof, etc.) and/or diamond-containing agglomerates. The discrete diamond particles may individually exhibit a desired grain size. The discrete diamond particles may comprise one or more of micro-sized diamond particles and nano-sized diamond particles. For example, an individual grain size of the discrete diamond particles may be within a range of from about 5 nanometers (nm) to about 100 microns (μm), such as within a range of from about 50 nm to about 50 μm, from about 100 nm to about 30 μm, from about 500 nm to about 20 μm, or from about 700 nm to about 10 μm. In some embodiments, grain sizes of the discrete diamond particles comprise a mixture of two or more monomodal grain size distributions. In addition, each of the discrete diamond particles may individually exhibit a desired shape, such as at least one of a spherical shape, a hexahedral shape, an ellipsoidal shape, a cylindrical shape, a conical shape, or an irregular shape. In some embodiments, each of the discrete diamond particles of the diamond powder exhibits a substantially spherical shape. The discrete diamond particles may be monodisperse, wherein each of the discrete diamond particles 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 one other of the discrete diamond particles.

Referring next to FIG. 2B, the diamond powder 104 and the supporting substrate 102 may be subjected to HPHT processing (e.g., a sintering process) to form the PDC 106 (e.g., a cutting table) on the supporting substrate 102. The supporting substrate 102 with the PDC 106 bonded thereto form the cutting element 108. The HPHT processing may include subjecting the diamond powder 104 and the supporting substrate 102 to elevated temperature and elevated pressures in a directly pressurized and/or indirectly heated cell for a sufficient time to convert the discrete diamond particles of the diamond powder 104 into inter-bonded diamond particles. Operating parameters (e.g., temperatures, pressures, durations, etc.) of the HPHT processing at least partially depend on the material compositions of the supporting substrate 102 and the diamond powder 104. Temperatures (e.g., sintering temperatures) within the pressurized, heated cell during the HPHT processing may be greater than or equal to about 1350° 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. In some embodiments, temperatures within the heated, pressurized cell may be greater than a solidus temperature (e.g., greater than the solidus temperature and less than or equal to the liquidus temperature, greater than or equal to the liquidus temperature, etc.) of the homogenized metal binder of the supporting substrate 102. Pressures within the pressurized, heated cell during the HPHT processing 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, pressures within the pressurized, heated cell during the HPHT processing are within a range of from about 5.0 GPa to about 9.0 GPa. The diamond powder 104 and the supporting substrate 102 may be held at such temperatures and pressures for a sufficient amount of time to facilitate the inter-bonding of the discrete diamond particles of the diamond powder 104 to form the PDC 106, such as, for example, a period of time between about 30 seconds to about 30 minutes.

During the HPHT processing, the homogenized metal binder of the supporting substrate 102 melts and at least a portion thereof is swept (e.g., mass transported, diffused) into the diamond powder 104. The homogenized metal binder received by the diamond powder 104 catalyzes the formation of inter-granular bonds between the discrete diamond particles of the diamond powder 104. The types, amounts, and distributions of individual elements of the homogenized metal binder swept into the diamond powder 104 during the HPHT processing may be at least substantially the same as the types, amounts, and distributions of individual elements of the homogenized metal binder of the supporting substrate 102. In other words, the material composition of the homogenized metal binder diffused into the diamond powder 104 during the HPHT processing to form the PDC 106 is at least substantially the same as the material composition of the homogenized metal binder of the supporting substrate 102 prior to the HPHT processing. Providing the supporting substrate 102 directly on the diamond powder 104 may ensure that desired and predetermined chemistries of the homogenized metal binder are swept into the diamond powder 104 during the HPHT processing.

The homogenized metal binder received by the diamond powder 104 promotes the formation of the inter-bonded diamond particles of the PDC 106. Depending on the types, amounts, and distributions of individual elements of the homogenized metal binder, substantially all of the homogenized metal binder swept into the diamond powder 104 may be reacted during the formation of the PDC 106. The material composition of the homogenized metal binder of the supporting substrate 102 may be selected to control the amount of the homogenized metal binder that remains following the formation of the PDC 106.

Since the supporting substrate 102 exhibits an at least substantially uniform capillary pressure profile due to the at least substantially uniform distribution of pores and the at least substantially uniform distribution of pore throat sizes, the homogenized metal binder may be at least substantially uniformly swept (e.g., mass-transported, diffused) into the diamond powder 104 during HPHT processing. In other words, the homogenized metal binder may at least substantially uniformly flow across the supporting substrate 102 and infiltrate the diamond powder 104 during HPHT processing. Since sizes of the smallest pore throats of the pores of the supporting substrate 102 are relatively larger than the smallest pore throats of pore throat sizes observed in conventional supporting substrates and since the supporting substrate 102 exhibits an at least substantially uniform capillary pressure profile resulting in at least substantially uniform flow of the homogenized metal binder, fracturing of the pore throats and subsequent eruptions of the homogenized metal binder into the diamond powder 104 may be reduced and/or eliminated. Macro-sized grains of a solid binder material formed within the PDC 106 due to eruptions of the homogenized metal binder during infiltration into the diamond powder 104 may be reduced and/or eliminated, improving the quality, strength, and reliability of the subsequently formed PDC 106.

The portion of the homogenized metal binder swept into the diamond powder 104 may facilitate the formation of a solid binder material within interstitial spaces between the inter-bonded diamond particles of the PDC 106. The solid binder material may be at least partially leached out of the PDC 106 proximate an exposed exterior surface of the PDC 106. In some embodiments, the solid binder material is at least substantially completely leached out of the PDC 106.

FIG. 3 depicts a partial cut-away perspective view of a cutting element 200, in accordance with embodiments of the disclosure. The cutting clement 200 may be formed in accordance with the methods previously described with reference to FIGS. 2A and 2B. In some embodiments, a cutting table 204 (e.g., a PDC) is formed in situ on a supporting substrate 202 during an HPHT process. The cutting element 200 and components thereof (e.g., the supporting substrate 202 and the cutting table 204) are at least substantially similar to the cutting element 108 and the components thereof (e.g., the supporting substrate 102 and the PDC 106) previously described in detail with reference to FIGS. 2A through 2B. The supporting substrate 202 with the cutting table 204 bonded thereto form the cutting element 200.

The cutting element 200 is depicted in FIG. 3 as exhibiting a cylindrical column shape. However, in some embodiments, the cutting element 200 may exhibit a different shape, such as, for example, a dome shape, a conical shape, a frusto-conical shape, a rectangular column shape, a pyramidal shape, a frusto-pyramidal shape, a fin shape, a pillar shape, a stud shape, or an irregular shape. An interface region 206 between the supporting substrate 202 and the cutting table 204 is depicted in FIG. 3 as being at least substantially planar. However, in some embodiments, the interface region 206 is at least substantially non-planar (e.g., convex, concave, ridged, sinusoidal, angled, jagged, V-shaped, U-shaped, irregularly shaped, etc.). For example, the supporting substrate 202 may include one or more protrusions and/or one or more recesses at the interface region 206 and the cutting table 204 may include one or more corresponding complementary recesses and/or corresponding complementary protrusions at the interface region 206.

A thickness (e.g., height) extending from an exposed major surface of the supporting substrate 202 to a cutting face 208 of the cutting element 200 may be within a range of from about 5 millimeters (mm) to about 25 mm, such as, for example, from about 7 mm to about 20 mm or from about 10 mm to about 15 mm. A thickness extending from the interface region 206 to the cutting face 208 of the cutting table 204 may be within a range of from about 0.3 mm to about 10 mm, such as, for example, from about 1 mm to about 5 mm or from about 1.5 mm to about 4 mm. A thickness extending from the interface region 206 to the exposed major surface of the supporting substrate 202 may be within a range of from about 0.7 mm to about 15 mm, such as, for example, from about 1 mm to about 10 mm, or from about 3 mm to about 7 mm.

The supporting substrate 202 may be a consolidated structure including the precursor composition previously described with reference to FIGS. 2A through 2B. For example, the supporting substrate 202 may be a consolidated structure including a combination of coarse WC particles and fine WC particles at least substantially evenly dispersed within a homogenized metal binder. The supporting substrate 202 is depicted in FIG. 3 as exhibiting a cylindrical column shape. However, the supporting substrate 202 may exhibit any suitable shape with respect to the shape of the cutting element 200.

The cutting table 204 is depicted in FIG. 3 as exhibiting a cylindrical column shape. However, the cutting table 204 may exhibit any suitable shape with respect to the shape of the cutting element 200. The cutting table may exhibit at least one lateral side surface 210, the cutting face 208 opposite the interface region 206, and at least one cutting edge 212 at a periphery of the cutting face 208. Surfaces (e.g., the at least one lateral side surface 210, the cutting face 208) of the cutting table 204 adjacent the cutting edge 212 may each be substantially planar, or one or more of the surfaces of the cutting table 204 adjacent the cutting edge 212 may be at least partially non-planar. Each of the surfaces of the cutting table 204 may be polished, or one or more of the surfaces of the cutting table 204 may be at least partially non-polished. The cutting edge 212 of the cutting table 204 may be at least partially (e.g., substantially) chamfered (e.g., beveled), at least partially (e.g., substantially) radiused (e.g., arcuate), at least partially chamfered and partially radiused, or may be non-chamfered and non-radiused. In some embodiments, the cutting edge 212 is chamfered, as shown in FIG. 3. The cutting edge 212 may include a single chamfer or may include multiple (e.g., more than one) chamfers.

The cutting table 204 is a PDC formed of inter-bonded diamond particles. The cutting table 204 may include a solid binder material within interstitial spaces between the inter-bonded diamond particles. In some embodiments, at least a portion of the solid binder material is leached out of the cutting table 204 proximate an exposed exterior surface of the cutting table 204. In some embodiments, at least substantially all of the solid binder material is leached out of the cutting table 204.

FIG. 4 is an enlarged cross-sectional view of a portion 214 of the cutting element 200 (FIG. 3). Particles of the supporting substrate 202 are enlarged to depict the coarse WC particles 216 and fine WC particles 218 of the discrete WC particles dispersed within the homogenized metal binder 220. The coarse WC particles 216 and the fine WC particles 218 are each at least substantially evenly distributed throughout the entirety of the supporting substrate 202. The fine WC particles 218 support (e.g., prop) the coarse WC particles 216 to provide an at least substantially uniform distribution of pores and an at least substantially uniform distribution of pore throats throughout the supporting substrate 202. Sizes of the smallest pore throats of the pores between the discrete WC particles of the supporting substrate 202 may be relatively larger than the smallest pore throat sizes of pores between carbide particles of a conventional supporting substrate. The cutting table 204 may be at least substantially free of macro-sized intrusions of the solid binder material in the diamond structure of the cutting table 204. In some embodiments, the cutting table 204 exhibits an at least substantially uniform diamond structure. In some embodiments, the cutting table 204 is at least substantially free of macro-sized grains of the solid binder material.

FIG. 5 is a perspective view of an earth-boring tool 300, including one or more cutting elements 302 (e.g., cutting elements 108, 200) in accordance with this disclosure. The earth-boring tool 300 may include a body 304 to which the cutting element(s) 302 may be secured. The earth-boring tool 300 specifically depicted in FIG. 5 is configured as a fixed-cutter earth-boring drill bit, including blades 306 projecting outward from a remainder of the body 304 and defining junk slots 308 between rotationally adjacent blades 306. In such an embodiment, the cutting element(s) 302 may be secured partially within pockets 310 extending into one or more of the blades 306 (e.g., proximate the rotationally leading portions of the blades 306 as primary cutting elements 302, rotationally following those portions as backup cutting elements 302, or both). However, cutting elements 302 as described herein may be bonded to and used on other types of earth-boring tools, including, for example, roller cone drill bits, percussion bits, core bits, eccentric bits, bicenter bits, reamers, expandable reamers, mills, hybrid bits, and other drilling bits and tools known in the art.

The embodiments of the disclosure described above and illustrated in the accompanying drawings do not limit the scope of the disclosure, which is encompassed by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of this disclosure. Indeed, various modifications of the disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements described, will become apparent to those skilled in the art from the description. Such modifications and embodiments also fall within the scope of the appended claims and equivalents.

CUTTING ELEMENTS, EARTH-BORING TOOLS INCLUDING SUCH CUTTING ELEMENTS, AND RELATED METHODS OF MAKING AND USING SAME

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