Polycrystalline compacts including nanoparticulate inclusions, cutting elements and earth-boring tools including such compacts, and methods of forming such compacts

Polycrystalline integrators and methods of forming these integrators

POLYCRYSTALLINE COMPACTS AND METHODS OF

FORMING SUCH COMPACTS

Full description

Background of the invention

The present invention relates generally to polycrystalline compacts, which may be used, for example, as cutting elements for earth-boring tools, and with methods for forming such polycrystalline compacts, cutting elements, and earth-boring tools earth‑boring tools.

Earth-boring tools for creating wellbores in subterranean earth formations generally involve multiple cutting elements attached to an object. For example, earth‑boring rotary drill bits fixed‑cutter drill bits (also referred to as drag bits) include several cutting elements that are fixedly attached to the body of the drill bit. Likewise, earth‑boring rotary drill bits with a roller cone may include cones which are mounted on bearing pins extending from the legs of the bit body such that each cone is able to rotate around the bearing pin on which it is installed. Several cutting elements may be fitted to each cone of the drill bit. In other words, earth‑boring tools typically include a bit body to which cutting elements are suspended.

The cutting elements used in earth-boring tools often include polycrystalline diamond compacts, which act as cutting faces of a diamond material

Crystals. Polycrystalline diamond material is a material that contains grains or crystals of diamond material interconnected. In other words, polycrystalline diamond material involves inter-granular bonds, directly between the grains or crystals of the diamond material. The terms "grain" and "crystal" are used synonymously and interchangeably here.

Polycrystalline diamond compact cutting elements are typically formed by sintering and bonding with relatively small diamond grains under conditions of high temperature and high pressure in the presence of a catalyst (e.g., cobalt, iron, nickel, or alloys and mixtures thereof) to form a layer (for example, a compact or “table”) of polycrystalline diamond material on a cutting element substrate. These processes are often referred to as high temperature/high pressure processes. The cutting element substrate may include a cermet material such as, for example, cobalt-cemented tungsten carbide. In such cases, cobalt (or other catalyst material) in the cutting element substrate may be forced into the diamond grains during sintering and act as the catalyst material for the formation of intergranular diamond-to-diamond bonds. granular diamond-to-diamond bonds, and the resulting diamond table, made of diamond grains. In other methods, powdered catalyst material may be mixed with diamond grains before sintering the grains together in a high-temperature/high-pressure process.

When a diamond table is formed using a high-temperature/high-pressure process, catalyst material may remain in the interstitial spaces between grains of diamond in the resulting polycrystalline diamond compact. The presence of the catalyst material in the diamond table may contribute to thermal damage in the diamond table when the cutting element is heated during use, due to friction at the point of contact between the cutting element and the formation.

Polycrystalline diamond compact cutting elements, by which the catalyst material remains in the polycrystalline diamond compact, are generally thermally stable up to a temperature of about seven hundred and fifty degrees Celsius (750 degrees Celsius). Although internal stress within the cutting element may begin to appear at temperatures exceeding about three hundred and fifty degrees Celsius (350 degrees Celsius). This internal stress is due at least in part to differences in thermal expansion rates between the diamond table and the cutting element substrate to which it is attached. This variation in thermal expansion rates may cause significant tensile and compressive stresses at the interface between the diamond table and the substrate, and may cause the diamond table to separate from the substrate. At a temperature of about seven hundred and fifty degrees Celsius (750 degrees Celsius) and above, stresses through the diamond table itself may increase significantly due to differences in the coefficients of thermal expansion of the diamond material and the catalyst material inside the diamond table. diamond table. For example, cobalt thermally expands significantly faster than diamond, which may cause cracks to form and spread within the diamond table, which may ultimately deteriorate the diamond table and the effectiveness of the cutting element.

Furthermore, at temperatures higher than about seven hundred and fifty degrees Celsius (750 degrees Celsius), some diamond crystals within the polycrystalline diamond compact may react with the catalyst material causing the diamond crystals to undergo decomposition. Chemical breakdown or back-conversion to another allotrope of carbon or another carbon-based material. For example, diamond crystals may transform into graphite at the diamond crystal boundaries, which may essentially weaken the diamond table. In addition, at very high temperatures, in addition to graphite, some crystals may transform diamond crystals to carbon monoxide and carbon dioxide.

In order to reduce the problems associated with different rates of thermal expansion and chemical breakdown of diamond crystals into polycrystalline diamond compact cutting elements, the so-called “thermally stable” polycrystalline diamond compacts were developed (which It is also known for its thermally stable products. Such a thermally stable polycrystalline diamond compact may be formed by leaching the catalyst material (e.g., cobalt) out of the interstitial spaces between the diamond crystals interconnected in the diamond table using, for example, An acid or combination of acids (for example, aqua regia). Essentially, the catalyst material may be removed from the diamond table, or the catalyst material may be removed from only part of it. A report has been prepared on thermally stable polycrystalline diamond compacts in which the catalyst material is essentially filtered out of the diamond table and is intended to be thermally stable up to temperatures of about one thousand and two hundred degrees Celsius (1200 degrees Celsius). It has also been reported, however, that leached diamond tables are relatively more brittle and subject to shear, compression, and tensile stresses than non-leached diamond tables. In addition, it is difficult to fully attach a leached diamond table to a supporting substrate. In an effort to provide cutting elements with polycrystalline diamond compacts that are more thermally stable relative to non-leached polycrystalline diamond compacts, but which are also less brittle and subject to shear stresses, compression, For fully filtered diamond panels, cutting elements are provided, including a diamond table in which the catalyst material has been filtered from part or Parts of a diamond table. For example, it is known to leaching catalyst material from the cutting face, from one side of the diamond table, or both, to the desired depth inside the diamond table, but without leaching all of the catalyst material. From the diamond table.

In some embodiments, the polycrystalline material 12 may be formed on a support substrate 16 (as shown in Fig. 1a) of cemented tungsten carbide or other suitable substrate material in a conventional high temperature/high pressure process of the type described, By way of a non-limiting example, in US Application No. 3745623 by Wentorf et al. (published July 17, 1973), or may be formed as a freestanding polycrystalline material 12 (i.e., without a supporting substrate 16) in a similar conventional high-temperature/high-pressure process as described, by way of an unlimited example. , in US Application No. 5127923 Bunting et al. (Published July 7, 1992).

The polycrystalline material 12 may be filtered using a leaching agent and process such as that more fully described in, for example, US Application No. 5127923 to Bunting et al (published July 7, 1992), and US Application No. 4224380 to Bovenkerk et al. (Published September 23, 1980). More specifically, aqua regia (a mixture of concentrated nitric acid (HNO3) and concentrated hydrochloric acid (HCl)) may be used to significantly remove catalyst material24 and/or non-catalytic nanoparticles. catalytic nanoparticles of interstitial spaces 22.

General description of the invention

In some embodiments, the present invention includes polycrystalline compacts comprising grains of hard material that are interconnected to form a polycrystalline hard material, and a plurality of non-catalytic nanoparticles dispersed in interstitial spaces between the grains of hard material. material.

In additional embodiments, the present invention includes cutting elements comprising at least one polycrystalline compact.

In additional embodiments, the present invention includes earth-boring tools including a body and at least one polycrystalline compact carried by the body.

In other embodiments, the present invention includes methods for forming polycrystalline compacts, in which a plurality of hard particles and a plurality of non-catalytic nanoparticles are sintered into interconnected grains of a hard material.

In additional embodiments, the present invention includes a method for creating cutting elements by which interstitial spaces between interconnected grains of hard material in a polycrystalline material are filtered by a plurality of non-catalytic nanoparticles.

Brief explanation of the drawings

While the specification is concluded with claims that specifically state and expressly state what is being considered in the form of embodiments of the present invention, various features and features of embodiments of the invention may be more easily ascertained from the following description of certain embodiments of the invention when read in conjunction with the accompanying drawings. , which has:

Figure 1a is a partially cut perspective drawing illustrating an embodiment of a cutting element comprising a polycrystalline compact of the present invention;

Figure 1b is a simplified drawing of how the microstructure of a polycrystalline compact might appear under magnification. It shows interconnected and dispersed macro- and micro-grains of a solid;

Figure 2 includes an enlarged view of part of Figure 1b, as well as simplified diagrams illustrating the different types of nanoparticles that may be used to manufacture a polycrystalline compact similar to those shown in Figures 1a and 1b; And

Figure 3 represents a perspective drawing of an embodiment of a fixed-cutter earth-boring rotary drill bit that includes multiple polycrystalline integrators similar to those shown in Figures 1a and 1b carried by the drill bit body.

Detailed description

The illustrations given here are not actual representations of any polycrystalline compact, microstructure of a polycrystalline compact, particle, cutting element, or drill bit, and are not drawn to scale, but representations have only been idealized and used to describe the present invention. . Additionally, common elements between shapes may still have the same numerical significance.

As used herein, the term "drill bit" 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, drill bits Core bits, eccentric bits, bi‑center bits, extended reamers, mills, drag bits, roller cone bits, hybrid bits, drilling bits and other tools known in the field.

As used herein, the term “nanoparticle” means and includes any particle having an average particle diameter of about 500 nanometers or less.

As used herein, the term “polycrystalline material” means and includes any material that contains many grains or crystals of the material that are held together by inter-granular bonds. The crystal structures of individual grains may be randomly oriented somewhere within the polycrystalline material.

As used herein, the term “polycrystalline compact” means and includes any structure comprising a polycrystalline material formed in a manner that involves the application of pressure (e.g., compaction) to the precursor material or materials used to compose the material. Polycrystalline material.

As used herein, the term "inter-granular bond" refers to and includes any direct atomic bond (e.g., covalent, metallic, and the like) between atoms in adjacent grains of a material.

As used herein, the term “catalyst material” refers to any material capable of essentially catalyzing the formation of inter-granular bonds between grains of a hard material during a high-temperature/high-pressure process. For example, catalyst materials for diamond include cobalt, iron, nickel, other elements from Group VIIIA of the periodic table of the elements, and alloys thereof.

As used herein, the term “non‑catalytic material” refers to any material that is not a catalyst material.

As used herein, the term “non-catalytic nanoparticle” means and includes any nanoparticle that does not contain a catalytic material, diamond, or cubic boron nitride. Non-catalytic nanoparticles may, in some embodiments, comprise materials that are not any type of hard material, as defined below.

As used herein, the term “hard material” means and includes any material that has a Knoop Knoop hardness value of about 2,000 kgf/mm2 (20 GPa) or greater. In some embodiments, the hardened materials used herein may have a Knoop hardness value of about 3,000 kgf/mm2 (29.4 GPa) or more. These materials include, for example, diamond or cubic boron nitride.

Figure 1a represents a simplified, partially cropped perspective view of an embodiment of a cutting element 10 of the present invention. The cutting element 10 includes a polycrystalline compact in the form of a layer of hard polycrystalline material 12, also known in the art as a polycrystalline table, that is provided on (e.g., built upon or attached to) a support substrate 16 supporting substrate with 14 interface between them. Although the cutting element 10 in the embodiment depicted in Figure 1a is cylindrical or disc-shaped, in other embodiments the cutting element 10 may have any desired shape, such as dome, cone, chisel, etc.

In some embodiments, the polycrystalline material 12 comprises a polycrystalline diamond. In those embodiments, the cutting element 10 may be referred to as a polycrystalline diamond compact cutting element. In other embodiments, the polycrystalline material 12 may include another hard material such as, for example, polycrystalline cubic boron nitride. boron nitride.

Figure 1b is an enlarged view of how the microstructure of a polycrystalline material 12 cutting element 10 might appear when magnified. As discussed in further detail below, the polycrystalline material includes 12 interbonded grains of the hard material. The polycrystalline material 12 also includes nanoparticles dispersed in interstitial spaces between the interbonded grains 18 of the hard material. These nanoparticle inclusions in the polycrystalline material may reduce the amount of catalyst material remaining in the polycrystalline material after the catalyst material is used to stimulate the formation of the polycrystalline material in the sintering process. process, such as high temperature/high pressure process. In other words, at least non-catalytic nanoparticulate inclusions (i.e., nanoparticles) may enter the polycrystalline material 12 such that an amount of catalyst material remains in the interstitial spaces between the interbonded grains 18 of the solid material hard material in microstructure after reduction sintering process by volumetric exclusion based on the presence of nanoparticles Without a catalyst, non-catalyst nanoparticles. The spatial volume occupied by these nanoparticles cannot be occupied by catalyst material, and hence, the amount of catalyst material in the polycrystalline material is reduced. The total reduction of catalytic material in the grain boundary regions between interbonded grains of a hard material may lead to an increase in the thermal stability of the cutting element 10 by having a low coefficient of thermal expansion from the reduced material content. Catalyst material. Furthermore, in embodiments in which the hard material includes a diamond, a reduction in the catalytic material between the interbonded grains of the hard material may also reduce the ability of the diamond to transform into graphite (often referred to as "reverse graphitization" for essentially the same reasons.

Nanoparticles dispersed in interstitial spaces between interbonded grains of a hard material may include a non-catalytic material. The non-catalytic material for nanoparticles may include, for example, one or more elementary metals (e.g., commercially pure tungsten), metal alloys (e.g., tungsten alloys tungsten alloys), intermetallic compounds, ceramics (for example, carbides, nitrides, oxides) and combinations thereof. As specific examples without limitation, non-catalytic nanoparticles may include carbides, nitrides, or carbonitrides of heat-resistant metals such as hafnium, vanadium, molybdenum, tungsten, niobium, and titanium.

As shown in Figure 1b, the grains 18 of the polycrystalline material 12 may optionally have a multi‑modal grain size distribution (e.g., bi‑modal, tri‑modal, etc.). ). In some embodiments, the polycrystalline material 12 may have a multi-modal grain size distribution as described in at least one of the patent applications from US provisional patent application serial number 61/232,265, filed on August 7 , 2009, titled “Polycrystalline Compacts Including In‑Situ Nucleated Grains, Earth‑Boring Tools Including Such Compacts, And Methods Of Forming Such Compacts And Tools,” U.S. patent application serial number 12/588,184, filed September 11, 2009. , It is titled “Polycrystalline Compacts Having Material Disposed In Interstitial Spaces Therein, Cutting Elements And Earth‑Boring Tools Including Such Compacts, And Methods Of Forming Such Compacts.”

For example, a layer of hard polycrystalline material may include a first plurality of 18 grains of hard material with an average grain size, and a second plurality of 18 grains of hard material with at least an average grain size. The second differs from the average grain size of the first grain because the first number of grains is 18 grains. For example, the average grain size of 18larger grains may be at least about one hundred and fifty (150) times larger than the average grain size of 18smaller grains. In additional embodiments, the average grain size of the 18 larger grains may be at least about five hundred (500) times larger than the average grain size of the smaller 18 smaller grains. In further embodiments, the average grain size of the 18 larger grains may be at least about seven hundred and fifty (750) times larger than the average grain size of the 18 smaller grains. The smaller grains 18 and larger grains 18 may be interspersed and interconnected to form the 12 layer of hard polycrystalline material. In other words, in embodiments in which the polycrystalline material 12 includes a polycrystalline diamond, smaller grains 18 and larger grains 18 may be mixed together and directly linked to each other by diamond-by-diamond intergrain bonds 26 (represented by scalpel lines in Fig. 1b).

As known in the art, the average grain size of grains within a microstructure may be determined by measuring the grains of the microstructure under magnification. For example, a scanning electron microscope, field emission scanning electron microscope, or transmission electron microscope may be used to view or image a surface of polycrystalline material 12 (e.g., a polished and patterned surface of polycrystalline material 12). Commercially available viewing systems are often used with these microscope systems, and these vision systems are capable of measuring the average grain size of grains within a microstructure.

For example, but not specifically, in embodiments in which the average grain size of the smaller 18 grains is between about one nanometer (1 nm) and about one hundred and fifty nanometers (150 nm), the average grain size of the 18 smaller grains may be about five microns. (5 microns) and about forty microns (40 microns). Thus, in some embodiments, the ratio of the average grain size of larger grains 18 to the average grain size of smaller grains 18 may be about 1:33 and about 1:40,000.

The large difference in average grain size between smaller grains 18 and larger grains 18 may cause interstitial places 22 or voids (represented by shaded areas in Figure 1b) within the microstructure of the polycrystalline material 12 (relative to conventional polycrystalline materials). polycrystalline materials), and the total size of interstitials 22 or voids may be more evenly distributed throughout the microstructure of the polycrystalline material 12. As a result, any material contained within the interstitial spaces 22 (for example, a carbon compound or catalyst material, as described below) may also be more evenly distributed throughout the microstructure of the polycrystalline material 12 within Relatively smaller interstitial spaces 22 here.

In some embodiments, the number of 18 smaller grains per unit volume of 12 polycrystalline material may be greater than the number of 18 larger grains per unit volume of 12 polycrystalline material.

18smaller grains may comprise about half a percent (0.5%) and about thirty percent (30%) by volume of polycrystalline material 12. More specifically, smaller grains may comprise about one-half percent and about ten percent (10%) by volume of polycrystalline material, or even about half a percent (0.5%) and about five percent (5%) by volume. Of the polycrystalline material 12 polycrystalline material. The remainder of the volume of the polycrystalline material 12 may be primarily comprised of larger grains 18. A relatively small percentage of the remainder of the volume of the polycrystalline material 12 (for example, less than about ten percent (10%)) may comprise interstitial spaces 22 between the smaller 18 grains and larger grains 18 of the solid material.

In some embodiments, the 18smaller grains in situ may include 18 in‑situ nucleated grains of hard material, as described in the aforementioned US provisional patent application serial number 61/232,265, filed on August 7, 2009. .

The interstitial spaces 22 between the grains 18 of the hard material may be occupied at least partially by non-catalytic nanoparticles and catalyst material.

Non-catalytic nanoparticle inclusions in polycrystalline material 12 may exhibit one or more of the following features.

Nanoparticle inclusions may have an average vertical axis length of under five hundred nanometers (500 nm).

The chemical composition may be chosen for non-catalytic nanoparticle inclusions such that they do not degrade, do not quench, or otherwise do not adversely affect the sintering of grains 18 of the hard material during the sintering process (e.g. A high temperature/high pressure sintering process used to form the polycrystalline material 12 (although it may, in some embodiments, control or prevent abnormal grain growth growth for grains 18).

The chemical composition may be chosen for non-catalytic nanoparticle inclusions so that they do not catalyze the decomposition of the hard material after the sintering process (e.g., high temperature/high pressure process) used to form the polycrystalline material 12 Or contribute to any increase in catalytic activity within the polycrystalline material after the sintering process. In some embodiments, nanoparticle inclusions may effectively reduce the catalytic activity within the polycrystalline material after the intering process. In other words, for example, if the polycrystalline material includes a polycrystalline diamond, nanoparticle inclusions may effectively reduce the sensitivity of the polycrystalline diamond to reverse graphitization.

Non-catalytic nanoparticle inclusions may be employed to facilitate inclusion with grains 18 of the hard material. In other words, the exterior surfaces of non-catalytic nanoparticles may be at least partially coated with a material (e.g., organic material) that facilitates controlled distribution of the nanoparticles with the matrix grains of the hard materials during processing. Before pre-sintering processing, the adhesion of nanoparticles to the grains of the hard material may also be enhanced.

Furthermore, materials used to employ one or more nanoparticles of non-catalytic nanoparticles, particles of hard material, and particles of catalyst material may be modified during processing in any desired manner by, For example, changing or removing functional groups in molecules of a functionalizing material. As non-limiting examples, in some embodiments, non-catalytic nanoparticles may be employed as described in U.S. Provisional Application No. 61/324142, filed on April 14, 2010, and a method entitled Preparing Polycrystalline Diamond from Derivatized Nanodiamond.

Figure 2 includes an expanded view of part of Figure 1b, as well as simplified diagrams illustrating the different types of non-catalytic nanoparticles that may be included in the polycrystalline material 12 within the interstitial spaces 22 between the grains 18 hard material.

As shown in Figure 2, in some embodiments, the non-catalytic nanoparticles may generally comprise spherical nanoparticles 20, generally disc-shaped or platelet-shaped nanoparticles 20b (which may Round or non-round), whisker nanoparticles, fiber 20g, or a combination of one or more of these nanoparticles.

The volume occupied by nanoparticles in the polycrystalline material may be in the range from about 0.01% to about 50% of the volume occupied by the grains (18hard) material in the polycrystalline material.

Some non-catalytic nanoparticles may be mechanically bonded to grains of the hard material after sintering (e.g., the high-temperature/high-pressure process used to form the polycrystalline material).

In some embodiments, the polycrystalline material 12 may also include a catalyst material 24 arranged in interstitial spaces 22 between the interbonded grains 18 of the polycrystalline hard material. The catalyst material 24 may include a catalyst used to catalyze the formation of intergranular bonds 26 between the smaller grains 18 and the larger grains 18 of the polycrystalline material 12. In other embodiments, however, the interstitial spaces 22 between the grains 18 in some or all regions of the polycrystalline material 12 may be at least devoid of such catalyst 24 catalyst material. In these embodiments, the interstitial spaces 22 may include voids filled with a gas (e.g., air), in addition to any non-catalytic nanoparticles contained herein.

In embodiments in which the polycrystalline material 12 includes a polycrystalline diamond, the catalyst material 24 catalyst material may include a Group VIIIA element (e.g., iron, cobalt, or nickel) or any alloy alloy, and the 24 catalyst material may include between about half a percent (0.1%) and about ten percent (10%) of the volume of the 12 hard polycrystalline material. In additional embodiments, the catalyst material 24 may include a carbonate material such as, for example, carbonate and one or more magnesium, calcium, strontium, and barium. Carbonates may also be used to stimulate the formation of polycrystalline diamonds.

The 12layer of hard polycrystalline material may be formed from the cutting element 10 using high temperature/high pressure. These processes, and the systems for implementing these processes, are generally known in the field. In some embodiments, the catalyst material 24 may be supplied from the supporting substrate 16 during the high temperature/high pressure process used to form the polycrystalline material 12. For example, the substrate 16 may include a cobalt-enhanced tungsten carbide material. Cobalt in cobalt‑cemented tungsten carbide may act as a catalyst material24 during the high temperature/high pressure process. Furthermore, in some embodiments, non-catalytic nanoparticles may also be supplied from the supporting substrate 16 during the high temperature/high pressure process used to form the polycrystalline material 12. For example, the substrate 16 may comprise a cobalt‑cemented tungsten carbide material which also includes non-catalytic nanoparticles therein. Cobalt and non-catalytic nanoparticles may force the substrate into hard material grains18.

To form polycrystalline material 12 in a high-temperature/high-pressure process, a mixture of particles including particles (for example, grains) of hard material and non-catalytic nanoparticles may be brought to high temperatures ( For example, temperatures greater than about 1,000°C (1,000°C) and increased pressures (e.g., pressures greater than about 5 GPa) to form inter-granular bonds between particles of matter Hard material, and thus the formation of interbonded grains 18 of hard polycrystalline material. In some embodiments, the particulate mixture may be subjected to a pressure greater than about 6 GPa and a temperature greater than about fifteen hundred degrees Celsius (1500 C) in a high-temperature/high-pressure process.

The time at high temperatures and pressures may be relatively short when compared to the conventional high temperature/high pressure process to prevent the atoms of the smaller grains from diffusing into, and being introduced into, the larger grains. For example, in some embodiments, the particulate mixture may be subjected to a pressure greater than about six gigapascals and a temperature greater than about one thousand five hundred degrees Celsius (1500 C) for less than about two minutes (2.0 min) during the high temperature/pressure process high.

In embodiments in which a carbonate catalyst material (e.g., carbonate of one or more magnesium, calcium, strontium, and barium) is used to catalyze the formation of a polycrystalline diamond, the particulate mixture may be exposed To a pressure greater than about seven and seven out of ten gigapascals (7.7) and a temperature greater than about two thousand degrees Celsius (2000 C).

The particulate mixture may include hard particles to form the grains (hard material) described previously here. The particulate mixture may also include at least one catalyst material particle and non-catalytic nanoparticles. In some embodiments, the particulate mixture may include a material such as a powder. In other embodiments, however, the particulate mixture may be performed by (e.g., on or in) another material, such as a sheet or film, which may be subjected to a high temperature/high pressure process. An organic binder material may also be included with the particulate mixture to facilitate processing.

Thus, in some embodiments, the non-catalytic nanoparticles may be mixed with the hard particles used to form the grains to form a particulate mixture, which is then sintered in a high-temperature/high-pressure process.

In some embodiments, the non-catalytic nanoparticles may be mixed with the hard particles used to form the grains before the sintering process. A modified high temperature/high pressure used to synthesize a nanoparticulate composite including non-catalytic nanoparticles Catalytic nanoparticles and nanoparticles of a solid material.

In some embodiments, non-catalytic nanoparticles may grow on, attach, adhere to, or otherwise attach to the hard particles used to form the grains prior to the sintering process. The non-catalytic nanoparticles may be suspended to the hard particles by employing the exterior surfaces of at least one of the non-catalytic nanoparticles and the hard particles. After suspending non-catalytic nanoparticles into hard particles, the resulting particulate mixture may be subjected to a high-temperature/high-pressure process to form a polycrystalline material, as described above.

In additional embodiments, the non-catalytic nanoparticles may be combined with the non-catalytic nanoparticles prior to the sintering process. For example, non-catalytic nanoparticles may be grown on, suspended, adhered to, or otherwise connected to catalyst particles (where the catalyst particles may be or include the catalyst material in some (In embodiments of the invention), coated particles of the catalyst may be combined with hard particles to form a particulate mixture prior to sintering. sintering process. The non-catalytic nanoparticles may be suspended to the catalyst material particles by functionalizing the exterior surfaces of at least one of the non-catalytic nanoparticles and the catalyst particles. After suspension of non-catalytic nanoparticles into catalyst particles and mixing with hard particles, the resulting particulate mixture may be subjected to a high-temperature/high-pressure process to form a polycrystalline material 12, as described above.

In some embodiments, non-catalytic nanoparticles may be grown on, suspended, attached to, or otherwise connected to both hard material particles and catalyst material particles, and coated particles may be combined to form a particle mixture particulate mixture.

As noted previously, a particulate mixture containing hard particles to form interbonded grains may be exposed to hard material and, optionally, non-catalytic nanoparticles and/or catalyst material (to catalyze the formation of 26 inter-granular bonds between 18 smaller grains and 18 larger grains), to a high temperature/high pressure process to form a polycrystalline material 12 material. As non-limiting examples, a particulate mixture may include a mixture as described in, and may be formed by, processes described in the aforementioned US Provisional Application No. 61/324142, filed on April 14, 2010 and under the title Preparing Polycrystalline Diamond from Derivatized Nanodiamond.

After the high temperature/high pressure process, the catalyst material (e.g., cobalt) and non-catalytic nanoparticles may be arranged in at least some of the interstitial spaces 22 between the interbonded smaller grains and the granules. Larger 18 larger grains.

Optionally, catalyst material 24, non-catalytic nanoparticles, or both catalyst material 24 catalytic and non-catalytic nanoparticles may be removed from polycrystalline material 12 after a high temperature/high pressure process using Processes known in the field.

For example, a leaching process may be used to remove catalyst material 24 and/or non-catalytic nanoparticles from interstitial spaces 22 between grains of hard material 18. For example, it is also known that Boiling hydrochloric acid (HCl) and boiling hydrofluoric acid (HF) as leaching agents. One particularly suitable leaching agent is hydrochloric acid (HCl) at a temperature above one hundred and ten degrees Celsius (110°C), which may be provided in contact with the polycrystalline material for a period of about two (2) to about sixty hours. (60), depending on the size of the body of the polycrystalline material 12. After leaching the polycrystalline material 12, the interstitial spaces 22 between the interconnected smaller grains 18 and the larger 18 grains within the polycrystalline material 12 subjected to the leaching process may be at least significantly free of catalyst 24 catalyst material. It is used to stimulate the formation of 26 inter-granular bonds between grains in polycrystalline material 12, and may be The least are significantly free of non-catalytic nanoparticles. Furthermore, a portion of the polycrystalline material 12 may be subjected to a leaching process, or the entire body of the polycrystalline material 12 may be subjected to a leaching process.

In additional embodiments of the present invention, non-catalytic nanoparticles may be introduced into the interstitial spaces 22 between the interbonded grains 18 of the hard, polycrystalline material 12 after the catalyst 24 and any other material in the interstitial spaces 22 have been removed from the interstitial spaces (eg, by a leaching process). For example, after the polycrystalline material 12 is subjected to a leaching process, non-catalytic nanoparticles may be introduced into the interstitial spaces 22 between the grains 18 of the hard material in the polycrystalline material 12. The non-catalytic nanoparticles may be suspended in a liquid (e.g., water or other polar solvent) to form a suspension, and the polycrystalline material 12 may be soaked in the suspension to allow the liquid and the non-catalytic nanoparticles to nanoparticles to seep into the interstitial spaces 22. The liquid (and the non‑catalytic nanoparticles suspended there) may be drawn into the interstitial spaces 22 by capillary forces. In some embodiments, pressure may be applied to the fluid to facilitate infiltration of the liquid suspension into the interstitial spaces 22.

After infiltrating the interstitial spaces 22 with liquid suspension, the polycrystalline material 12 may be dried to remove the liquid from the interstitial spaces, leaving behind non-catalytic nanoparticles there. Optionally, a thermal treatment process may be used to facilitate the drying process.

The polycrystalline material 12 may then be subjected to a thermal process (e.g., standard vacuum furnace sintering process) to at least partially sinter the non-catalytic nanoparticles within the interstitial spaces 22 in the material Polycrystalline 12 polycrystalline material. This process may be carried out below any temperature that would be harmful to the polycrystalline material.

Embodiments of the cutting elements 10 of the present invention comprising a polycrystalline compact include a polycrystalline material 12 configured as previously described herein, for example the cutting element 10 shown in Figure 1a may be formed and installed with a ground drilling tool. earth‑boring tool, for example, rotary drill bit, percussion bit, coring bit, eccentric bit, reamer tool, milling tool, etc., For use in wellbores in subterranean formations. As a non-specific example, Figure 3 shows an earth-boring rotary drill bit of a fixed cutter type comprising 10 cutting elements, each of which includes a polycrystalline compact comprising 12 polycrystalline material as described Previously here. The 36 rotary drill bit includes a 38 bit body, and 10 cutting elements, including 12 polycrystalline compacts, which are carried by (i.e., attached to) the 38 bit body. The 10 cutting elements may be hardened (or otherwise fixed) within pockets formed on the outside of the 38 bit body.

Polycrystalline hard materials that include non-catalytic nanoparticles in the interbonded grains of the hard material, as described above, may exhibit improved thermal stability and mechanical durability. durability, or both improved thermal stability and improved mechanical durability for polycrystalline hard materials Previously known. By including non-catalytic nanoparticles in the interbonded grains of the hard material, less catalyst material may be placed in the interbonded grains of the final polycrystalline hard material, which It may improve one or both of the thermal stability and mechanical durability of the polycrystalline solid.

Additional unlimited example embodiments of the invention are described below.

Embodiment 1: polycrystalline compact, including:

A group of hard material grains, a group of hard material grains that are linked together to form a polycrystalline hard material. A group of non-catalytic nanoparticles placed in the interstitial spaces between grains of hard material.

Embodiment 2: Polycrystalline compact According to Embodiment 1, the set of hard material grains includes diamond grains.

Embodiment 3: polycrystalline compact according to embodiment 1 or embodiment 2, wherein the nanoparticles of the non-catalytic nanoparticle group comprise at least one of a metal, a metal alloy, an intermetallic compound, and a ceramic .

Embodiment 4: The polycrystalline compact according to any of embodiments 1 through 3, wherein the nanoparticles of the non-catalytic nanoparticles group comprise at least one carbide, nitride, and oxide.

Embodiment 5: The polycrystalline compact, according to any of Embodiments 1 through 4, further includes a catalyst material in the interstitial spaces between the grains of the hard material.

Embodiment 6: polycrystalline compact according to any of Embodiments 1 through 5, where the set of hard material grains includes:

A group of smaller grains of a solid material that has an average first grain size; And

A group of larger grains of a hard material that has an average second grain size that is at least one hundred and fifty (150) times larger than the first average grain size.

Embodiment 7: Polycrystalline compact According to Embodiment 6, where the average grain size of the second is between two hundred and fifty (250) times seven hundred and fifty (750) times larger than the average grain size of the first.

Embodiment 8: polycrystalline compact according to Embodiment 6 or Embodiment 7, where the average grain size of the first is between about one nanometer (1 nm) and about one hundred and fifty nanometers (150 nm), and the average grain size of the second is between about five microns ( 5 m) and about forty microns (40 m).

Embodiment 9: The polycrystalline compact according to any of Embodiments 1 through 8, wherein the total volume occupied by the population of non-catalytic nanoparticles in the polycrystalline hard material is in a range from about 0.01% to about 50%. % of the total volume occupied by grains of hard material in polycrystalline hard material.

Embodiment 10: a cutting element, including:

substrate; And

A polycrystalline compact as mentioned in any of embodiments 1 through 9 on the substrate.

Embodiment 11: An earth‑boring tool comprising a body and a polycrystalline compact as described in any of Embodiments 1 through 9 carried by the body.

Embodiment 12: The earth‑boring tool according to Embodiment 11, wherein the earth‑boring tool is a fixed‑cutter rotary drill bit.

Figure 13: A method for forming a compact polycrystalline, comprising intering an array of hard particles and an array of non-catalytic nanoparticles to form a polycrystalline hard material comprising an array of interbonded grains of a hard material.

Embodiment 14: The method according to Embodiment 13 also includes selecting each of the hard particles for the set of hard particles to include a diamond.

Embodiment 15: The method in accordance with Embodiment 13 or Embodiment 14 further includes selecting the nanoparticles of the non-catalytic nanoparticle group to include at least one of a metal, a metal alloy, an intermetallic compound, and a ceramic.

Embodiment 16: The method according to Embodiments 13 through 15 further includes selecting the nanoparticles of the non-catalytic nanoparticles group to include at least one carbide, nitride, and oxide.

Embodiment 17: The method according to any of Embodiments 13 through 16, further comprising catalyzing the formation of intergranular bonds between grains of the hard material.

Embodiment 18: The method according to any of Embodiments 13 through 17, wherein sintering the hard particles and the non-catalytic nanoparticles comprises sintering the hard particles and the non-catalytic nanoparticles in a high-temperature/high-pressure process.

Embodiment 19: The method according to any of Embodiments 13 through 18, further comprising adhesion of the nanoparticles of the non-catalytic nanoparticle group to the exterior surfaces of the hard particles of the hard particle group before sintering the hard particle group and the particle group Non-catalytic nanoparticles.

Embodiment 20: The method according to element 19, further comprising functionalizing at least one of the group of hard particles and the group of non-catalytic nanoparticles to induce adhesion of the nanoparticles of the group of non-catalytic nanoparticles to the exterior surfaces of the solid particles. hard particles for the group of hard particles.

Figure 21: A method for forming a cutting element, including infiltrating the interstitial spaces between interbonded grains of the hard material in a polycrystalline material with an array of non-catalytic nanoparticles.

Embodiment 22: The method, according to Embodiment 21, also includes selecting hard material grains to include diamond grains.

Embodiment 23: The method according to Embodiment 21 or Embodiment 22 further includes selecting the nanoparticles of the non-catalytic nanoparticle group to include at least one of a metal, a metal alloy, an intermetallic compound, and a ceramic.

Embodiment 24: The method according to any of Embodiments 21 through 23 further includes selecting the nanoparticles of the non-catalytic nanoparticles group to include at least one carbide, nitride, and oxide.

The previous description is directed to special embodiments for the purpose of clarification and explanation. It will be obvious, however, to a person skilled in the art that many modifications and changes to the embodiments set forth above are possible without deviating from the scope of the embodiments described herein as stated below, including legal equivalents. The purpose is to interpret the following items as including all such modifications and changes.