METHODS FOR MANUFACTURING POLYCRYSTALLINE ULTRA-HARD CONSTRUCTIONS AND POLYCRYSTALLINE ULTRA-HARD CONSTRUCTIONS

- SMITH INTERNATIONAL, INC.

Polycrystalline ultra-hard constructions are made by subjecting a sintered ultra-hard body, substantially free of a sintering catalyst material, to a further HPHT process. The process is controlled to initially melt and infiltrating a filler material into the sintered ultra-hard body to form a filler region having interstitial regions filled with the filler material. The filler region extends a partial depth into the sintered ultra-hard body and is formed at a temperature below the melting temperature of an infiltrant material. Next, the process is controlled to melt and infiltrate the infiltrant material into the sintered ultra-hard body to form an infiltrant region that extends a partial depth into the sintered ultra-hard body. A portion of the filler region and/or the infiltrant region may be removed to form a thermally stable region.

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Description
CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/578,079 filed Dec. 20, 2011, which is incorporated herein by reference in its entirety.

FIELD

Improved methods for forming polycrystalline ultra-hard constructions, and polycrystalline ultra-hard constructions resulting from such improved methods, are disclosed herein.

BACKGROUND

The existence and use polycrystalline diamond material types for forming tooling, cutting and/or wear elements is well known in the art. For example, polycrystalline diamond (PCD) is known to be used as cutting elements to remove metals, rock, plastic and a variety of composite materials. Such known polycrystalline diamond materials have a microstructure characterized by a polycrystalline diamond matrix first phase, that generally occupies the highest volume percent in the microstructure and that has the greatest hardness, and a plurality of second phases, that are generally filled with a solvent catalyst material used to facilitate the bonding together of diamond particles, grains or crystals together to form the polycrystalline matrix first phase during sintering.

PCD known in the art is formed by combining diamond grains (that will create the polycrystalline matrix first phase) with a suitable solvent catalyst material (that will create the second phase) to form a mixture. The solvent catalyst material can be provided in the form of powder and mixed with the diamond grains or can be infiltrated into the diamond grains during high pressure/high temperature (HPHT) sintering. The diamond grains and solvent catalyst material are sintered at extremely high pressure/high temperature process conditions, during which time the solvent catalyst material promotes desired intercrystalline diamond-to-diamond bonding between the grains, thereby forming a PCD structure.

Solvent catalyst materials used for forming conventional PCD include solvent metals from Group VIII of the Periodic table, with cobalt (Co) being the most common. Conventional PCD can comprise from about 85 to 95% by volume diamond and a remaining amount being the solvent metal catalyst material. The solvent catalyst material is present in the microstructure of the PCD material within interstices or interstitial regions that exist between the directly bonded together diamond particles and/or along the surfaces of the diamond particles.

The resulting PCD structure produces enhanced properties of wear resistance and hardness, making PCD materials extremely useful in aggressive wear and cutting applications where high levels of wear resistance and hardness are desired. Industries that utilize such PCD materials for cutting, e.g., in the form of a cutting element, include automotive, oil and gas, aerospace, nuclear and transportation to mention only a few.

For use in the oil production industry, such PCD cutting elements are provided in the form of specially designed cutting elements such as shear cutters that are configured for attachment with a subterranean drilling device, e.g., a shear or drag bit. Thus, such PCD shear cutters are used as the cutting elements in shear bits that drill holes in the earth for oil and gas exploration. Such shear cutters generally comprise a PCD body that is joined to substrate, e.g., a substrate that is formed from cemented tungsten carbide. The shear cutter is manufactured using an HPHT process that utilizes cobalt as a catalytic second phase material that facilitates liquid-phase sintering between diamond particles to form a single interconnected polycrystalline matrix of diamond with cobalt dispersed throughout the matrix.

The shear cutter is attached to the shear bit via the substrate, usually by a braze material, leaving the PCD body exposed as a cutting element to shear rock as the shear bit rotates. High forces are generated at the PCD/rock interface to shear the rock away. In addition, high temperatures are generated at this cutting interface, which shorten the cutting life of the PCD cutting edge. High temperatures incurred during operation cause the cobalt in the diamond matrix to thermally expand and even change phase, which thermal expansion is known to cause the diamond crystalline bonds within the microstructure to be broken at or near the cutting edge thereby also operating to reduce the life of the PCD cutter. Also, in high temperature oxidizing cutting environments, the cobalt in the PCD matrix will facilitate the conversion of diamond back to graphite, which is also known to radically decrease the performance life of the cutting element.

Attempts in the art to address the above-noted limitations have largely focused on the solvent catalyst material's degradation of the PCD construction by catalytic operation, and have involved removing the catalyst material from the PCD construction for the purpose of enhancing the service life of PCD cutting elements. For example, it is known to treat the PCD body to remove the solvent catalyst material therefrom, which treatment has been shown to produce a resulting diamond body having enhanced cutting performance. One known way of doing this involves at least a two-stage technique of first forming a conventional sintered PCD body, by combining diamond grains and a solvent catalyst material and subjecting the same to HPHT process as described above, and then removing the solvent catalyst material therefrom, e.g., by acid leaching process.

As discussed in US 2008/0230280 A1 and US 2008/0223623 A1, an approach to providing a thermally stable PCD construction is to form a PCD body during a HPHT sintering process and then remove substantially all of the solvent catalyst material from the PCD body so that the remaining thermally stable PCD (TSP) body comprises essentially a matrix of intercrystalline bonded together diamond crystals with no other material occupying the interstitial regions between the diamond crystals. While such a TSP body may display improved thermal properties, it now lacks toughness that may make it unsuited for particular high-impact cutting and/or wear applications.

Therefore, it is known to infiltrate the TSP with an infiltrant material, for example selected from Group VIII elements from the Periodic Table, such as Co, Ni and/or Fe. The infiltrant material may be provided via migration by re-bonding the treated PCD body to a substrate during a HPHT re-bonding process, wherein the infiltrant material present as a constituent in the substrate liquefies and infiltrates into the TSP body, also attaching the body to the substrate. After infiltration of the infiltrant material, the infiltrated TSP body is treated again, this time, to remove the infiltrant material from a surface of the PCD body.

Such reattached treated PCD (or TSP) cutting elements comprising such infiltrants can fail prematurely during use. Without wishing to be bound by any particular theory, it is believed that the failure of such reattached PCD cutting elements can be due to insufficient migration of the infiltrant material into the treated PCD body during the infiltration process (e.g., re-bonding process). Insufficient migration of the infiltrant material produces residual porosity in the infiltrated TSP body. If the pores or voids created from treating the PCD body to remove the catalyst material are partially infiltrated, or otherwise not properly infiltrated during the infiltration process, the empty pores can weaken the body and create structural flaws in the microstructure leading to premature failure of the cutting element. Partial infiltration, thus makes the PCD body vulnerable to cracking during finishing operations such as lapping or grinding, and also can make re-treating the PCD body to remove infiltrant material more difficult, which can weaken the bond between the PCD body and an attached substrate.

Insufficient migration of the infiltrant during the infiltration process can be due to the sluggish infiltration kinetics of the infiltrant material (e.g., cobalt) and the porosity and/or the small pores of the PCD body. For example, the infiltration of an infiltrant such as cobalt from carbide, e.g., present as a constituent in a WC—Co substrate, is very difficult such that in many cases the cobalt is not able to fully infiltrate the PCD body during HPHT processing, leading to the degradation of diamond in the partially infiltrated region, and operating to reduce the wear resistance of the PCD body.

Further, when the treated PCD body is taken to pressure and heated to melt the infiltrant (e.g., cobalt), there is a period of time which the diamond in the pore space of the body is out of the diamond stable region, i.e., there is temperature but insufficient pressure. This situation can cause damage to the diamond structure and weaken the diamond bonds, operating to further reduce the wear resistance, strength and service life of the PCD body and cutting element formed therefrom.

As discussed in US 2010/0320006 A1, one approach to improving the infiltration of the infiltrant material is to increase the porosity in the treated PCD body near the source of the infiltrant material (e.g., substrate). While such approach may operate to facilitate the migration of the infiltrant into the PCD body, the increase in porosity decreases the overall diamond density or diamond volume of the PCD body, thereby operating to weaken the structure of the PCD body and reduce the service life of the cutting element formed therefrom.

It is, therefore, desirable to provide polycrystalline ultra-hard constructions, and methods for making the same, engineered in a manner that not only have improved thermal characteristics to provide an improved degree of thermal stability during use, but that do so in a manner that maintains the desired wear resistance and diamond density or diamond volume, thereby minimizing or eliminating known mechanisms of premature failure as compared to conventional PCD constructions. It is further desired that such polycrystalline ultra-hard constructions be engineered in a manner that facilitates the manufacturing process, to provide manufacturing efficiencies when compared to conventional PCD constructions.

SUMMARY

Polycrystalline ultra-hard constructions prepared according to principles of this disclosure are made by subjecting a sintered ultra-hard body that is substantially free of a catalyst material used to initially sinter the ultra-hard body at high pressure/high temperature conditions to a further high pressure/high temperature process to introduce an infiltrant material. The sintered ultra-hard body comprises a matrix phase of directly bonded together ultra-hard particles, and a plurality of substantially empty interstitial regions disposed within the matrix. In an example embodiment, the ultra-hard material is diamond, and the matrix phase is intercrystalline bonded together diamond crystals.

In an example embodiment, the further high pressure/high temperature process is performed in a controlled manner to minimize damage to the matrix phase. In such example embodiment, the process comprises melting and infiltrating a filler material into the sintered ultra-hard body to form a filler region having interstitial regions filled with the filler material. In an example embodiment, the filler region extends a partial depth into the sintered ultra-hard body and is formed at a temperature below the melting temperature of an infiltrant material and at a pressure below about 3 GPa. The filler material may be placed adjacent a surface, e.g., a working surface, of the ultra-hard body before melting and introducing the filler material.

In an example embodiment, the filler material has a melting temperature of less than about 1,000° C., may have a melting temperature of less than about 700° C., and in some embodiments may have a melting temperature of less than about 300° C. The filler material may be selected from the group including aluminum, gallium, copper, zinc, silver, indium, thallium, tin, lead, bismuth, alloys, metal salts, carbonates, fluorides, chlorides, bromides, sulfides and mixtures thereof. In an example embodiment, the filler material may be an alloy which is a eutectic alloy.

The process further comprises next melting and infiltrating the infiltrant material into the sintered ultra-hard body, now comprising the filler region, to form an infiltrant region. In an example embodiment, the melting and infiltrating of the infiltrant material occurs at a temperature and pressure greater than that used to form the filler region. The infiltrant region extends a partial depth into the sintered ultra-hard body. Thus, after melting and infiltrating the infiltrant material, the sintered ultra-hard body consists of the filler region and infiltrant region.

In an example embodiment, during melting and infiltrating the infiltrant material, a sufficient population of the interstitial regions within the sintered ultra-hard body is filled with either the filler material or the infiltrant material to ensure that the sintered ultra-hard body remains above the Berman/Simon diamond-graphite equilibrium line. For example, after melting and infiltrating the infiltrant material less than about 2 percent of the population of the interstitial regions within the sintered ultra-hard body are empty, preferably about 0 to 2 percent of the population of the interstitial regions within the sintered ultra-hard body are empty, and more preferably about 0 to 1 percent of the population of the interstitial regions within the sintered ultra-hard body are empty. In an example, after melting and infiltrating the infiltrant material essentially 100 percent of the interstitial regions are filled.

During the further high pressure/high temperature process, a substrate may be attached to the ultra-hard body, e.g., the substrate may be the source of the infiltrant, and may be attached to the attached to the body adjacent the body infiltrant region.

In an example embodiment, after the infiltrant region is formed, the ultra-hard body may be treated to remove all or a portion of the filler material from the filler region to provide a thermally stable region. The thermally stable region may comprise less than about 12 percent by weight filler material, based on the total weight of the ultra-hard body, and in some embodiments the thermally stable region may comprise less than about 2 percent by weight filler material, based on the total weight of the ultra-hard body. In an example embodiment, the thermally stable region extends a depth of at least about 0.5 mm from a surface of the ultra-hard body including one or both of a top and side surface. Additionally, the thermally stable region may include a portion of the infiltrant region.

Polycrystalline ultra-hard constructions made in this manner display improved thermal characteristics to provide an improved degree of thermal stability during use, when compared to conventional polycrystalline ultra-hard constructions, and do so in a manner that maintains the desired wear resistance and diamond density or diamond volume, thus minimizing or eliminating known mechanisms of premature failure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of polycrystalline ultra-hard constructions and methods of making the same as disclosed herein will be appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 illustrates a phase diagram for diamond;

FIG. 2 illustrates a cross-sectional schematic side view of an ultra-hard construction according to one or more embodiments of the present disclosure;

FIG. 3 illustrates a cross-sectional schematic side view of an ultra-hard construction according to one or more embodiments of the present disclosure;

FIG. 4A is a schematic view of a region taken from a polycrystalline diamond body comprising an infiltrant material disposed interstitially between bonded together diamond particles according to methods disclosed herein;

FIG. 4B is a schematic view of a region taken from a polycrystalline diamond body that is substantially free of the infiltrant material of FIG. 4A according to methods disclosed herein;

FIGS. 5A to 5C are cross-sectional schematic side views of polycrystalline diamond constructions of one or more embodiments of the present disclosure during different stages of formation;

FIGS. 6A to 6C are cross-sectional schematic side views of polycrystalline diamond constructions of one or more embodiments of the present disclosure during different stages of formation;

FIG. 7 is a perspective side view of an insert comprising a polycrystalline diamond construction as disclosed herein;

FIG. 8 is a perspective side view of a roller cone drill bit comprising a number of the inserts of FIG. 7;

FIG. 9 is a perspective side view of a percussion or hammer bit comprising a number of inserts of FIG. 7;

FIG. 10 is a schematic perspective side view of a diamond shear cutter comprising a polycrystalline diamond construction as disclosed herein; and

FIG. 11 is a perspective side view of a drag bit comprising a number of the shear cutters of FIG. 10.

 DETAILED DESCRIPTION

Ultra-hard constructions of the present disclosure, for example polycrystalline diamond constructions, have a material microstructure comprising a polycrystalline matrix first phase that is formed from bonded together ultra-hard particles, such as directly bonded together diamond particles (grains or crystals), i.e., intercrystalline diamond. The ultra-hard body further includes interstitial regions disposed between the ultra-hard particles. The interstitial regions initially contain the catalyst material utilized to form the ultra-hard body during HPHT processing. The ultra-hard body is treated to remove the catalyst material from throughout the body. An infiltrant material is then introduced into at least one region of the treated ultra-hard body, and a filler material is also introduced into at least one other region of the treated ultra-hard body.

The resulting ultra-hard body comprises at least one region of the body containing a population of interstitial regions filled with an infiltrant material (infiltrant region), and at least one other region of the body containing a population of interstitial regions filled with a filler material (filler region). The filler material has a melting temperature that is lower than the infiltrant material. In one or more embodiments, the filler material may be non-reactive or inert to the ultra-hard body. In one or more embodiments, at least a portion of the infiltrant material may be provided from a substrate attached to the ultra-hard body during a re-bonding process, thereby forming a polycrystalline ultra-hard compact construction. However, polycrystalline ultra-hard constructions of the present disclosure may be provided in the form of a polycrystalline ultra-hard body that may or may not be attached to a substrate.

Use of a lower melting temperature filler material to infiltrate at least one region of the polycrystalline ultra-hard body provides for improved infiltration of the ultra-hard body by both the infiltrant material and the filler material. Having un-infiltrated or partially infiltrated interstitial regions present during infiltration of the treated ultra-hard body creates a region within the ultra-hard material, for example diamond, that is exposed to ultra high temperatures without sufficient high pressure, e.g., during HPHT processing.

Lack of adequate filler or infiltrant, e.g., metal or salt, within the interstitial regions during such HPHT processing results in insufficient pressure being experienced within these regions, which shifts the diamond out of the diamond stable region and into the graphite region of the phase diagram as illustrated in FIG. 1. Localized graphitization of the diamond weakens the diamond material and ultra-hard body formed therefrom, which can lead to unsatisfactory performance and reduced service life when placed into an end-use application. Polycrystalline ultra-hard constructions, prepared according to principles of the present disclosure are substantially free of interstitial regions that are un-infiltrated or partially infiltrated through the use of the infiltrant and filler, thereby producing an ultra-hard body displaying improved properties of thermal stability, wear resistance, impact resistance and/or toughness when compared known PCD constructions.

In one or more embodiments of the present disclosure, the ultra-hard body comprising at least one infiltrant region and at least one filler region may be further treated to remove the filler material from a population of the interstitial regions of the body, thereby forming a thermally stable region with interstitial regions that may be substantially free of the filler material, for example substantially empty interstitial regions.

As the interstitial regions (pores) can be very small, especially within a sintered ultra-hard body subjected to an additional HPHT process, the use of a filler material as described herein allows for better infiltration into the ultra-hard body and for more complete pore filling than with the use of an infiltration material, e.g., such as one selected from Group VIII of the Periodic table like Co, Ni and/or Fe, due partially to the lower viscosity of the filler material. As discussed above, the improved infiltration provided by the filler material operates to reduce the amount of ultra-hard material exposed to HPHT conditions outside the stable region due to unfilled pores that cause the pressure in such region to fall below the diamond stable pressure.

Additionally, using the filler material allows for deeper infiltration and penetration into the ultra-hard body from a working surface. Additionally, the filler material is more easily removed as compared to conventional infiltrant materials, such as those disclosed above, thereby enabling deeper leach depths to be obtained without the associated increase in leach time and difficulty. Additionally, use of the filler material enables removal by techniques different from and/or more efficient than those associated with catalyst and infiltrant materials. For example, filler materials as disclosed herein may be drawn out of the ultra-hard body by heat, such as in the case of the filler material being tin, in which case a copper disc can be placed adjacent the ultra-hard body to melt the tin and draw the tin out of the body and onto the disc.

As used herein, the term “ultra-hard” is understood to refer generally to materials having a Vickers hardness of greater than about 4,000, including but not limited to materials such as diamond, cubic boron nitride and the like.

As used herein, the term “working surface” refers to the surface or surfaces of the ultra-hard body intended to engage the formation during drilling. The working surface may include at least a portion of the top surface, side surface, cutting edge and combinations thereof.

As used herein, the term “depth” refers to the depth within the PCD body as measured inwardly perpendicular from the surface of interest of the body to the targeted interface (i.e., the boundary between regions within the PCD body).

As used herein, the term “polycrystalline diamond” refers to a material that has been formed at high pressure/high temperature (HPHT) conditions that has a material microstructure comprising a matrix phase of bonded-together diamond particles. The material microstructure further includes a plurality of interstitial regions that are disposed between the diamond particles. A catalyst material occupies the interstitial regions after the diamond powder is subjected to a HPHT sintering process.

As used herein, a plurality of items, structural elements, compositional elements and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.

Concentrations, quantities, amounts, and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a numerical range of 1 to 4.5 should be interpreted to include not only the explicitly recited limits of 1 to 4.5, but also include individual numerals such as 2, 3, 4 and sub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges reciting only one numerical value, such as “at most 4.5,” which should be interpreted to include all of the above-recited values and ranges. Further, such an interpretation should apply regardless of the breadth of the range or the characteristic being described.

Polycrystalline diamond (PCD) useful for making ultra-hard constructions as disclosed herein may be formed by conventional methods of subjecting precursor diamond grains or powder to HPHT sintering conditions in the presence of a catalyst material, e.g., a solvent metal catalyst, that functions to facilitate the direct bonding together of the diamond grains at temperatures of between about 1,350 to 1,500° C., and pressures of 5,000 MPa or higher. Suitable catalyst materials useful for making PCD include those metals identified in Group VIII of the Periodic table (CAS version in the CRC Handbook of Chemistry and Physics 75th edition, front cover), such as Co, Ni, Fe and combinations thereof.

As used herein, the term “thermal characteristics” is understood to refer to characteristics that impact the thermal stability of the resulting polycrystalline construction, which can depend on such factors as the relative thermal compatibilities such as thermal expansion properties, of the materials occupying and/or forming the different construction material phases.

As used herein, the term “catalyzing material” refers to a material that may be used to initially form the ultra-hard material body (e.g., polycrystalline diamond body).

As used herein, the term “infiltrant material” is understood to refer to materials other than the catalyst material that was used to initially form or sinter the ultra-hard material body, and may include materials identified in Group VIII of the Periodic table that have subsequently been introduced into the sintered ultra-hard material body after the catalyst material used to initially form the same has been removed therefrom. Additionally, the term “infiltrant material” is not intended to be limiting on the particular method or technique used to introduce such material into the already-formed ultra-hard material body.

In one or more embodiment, the diamond body comprises a first region (infiltrant region) that includes an infiltrant material. The infiltrant material may be a Group VIII material. The infiltrant material is disposed within a population of the interstitial regions within the first region. In an example embodiment, the first region of the diamond body is positioned remote from a diamond body surface, e.g., a working surface. The diamond body includes a second region (filler region) that extends a depth from the diamond body surface, e.g., a working surface. In one or more embodiments, the second region may be positioned adjacent the first region. In this embodiment, it is understood that there may not be a distinct interface between the first and second region but there may be a zone of intermixing between the infiltrant material and the filler material along the interface. The major portion of the second region comprises interstitial regions that are substantially free of the infiltrant material and contain the filler material. In an example embodiment, the second region extends a depth from one or more surfaces of the body including top, cutting edge and/or side surfaces, which may or may not be working surfaces.

In the one or more embodiments, where the diamond body is further treated to remove the filler material therefrom, the diamond body comprises a third region (thermally stable region) that extends a depth from the diamond body surface, e.g., a working surface. In one or more embodiments, the third region may extend a depth into the second region (filler region).

As illustrated in FIG. 2, a PCD body 211 is formed containing a first region (infiltrant region) 222 and a second region (filler region) 233, wherein the first region extends a depth from one body surface inwardly towards the body, and the second region extends a depth from another body surface inwardly towards the body. The PCD body is subsequently treated to form a third region (thermally stable region) 244, wherein the interstitial regions within the third region are substantially empty, and wherein the third region extends a depth from the same body surface as the second region. In one or more embodiments, the third region 244 may extend a depth through the second region (filler region) and into the first region (infiltrant region). If desired, the third region may be contained to a partial or full depth of the second region, i.e., without extending into the first region.

As illustrated in FIG. 3, a PCD body 311 is formed containing a first region (infiltrant region) 322 and a second region (filler region) 333. The PCD body is subsequently treated to form a third region (thermally stable region) 344 extending through the second region (filler region) 333 and into a portion of the first region (infiltrant region) 322 forming a fourth region of infiltrant material 355. The interface between the first region and the second region is indicated by a dashed line 366. In such embodiment, the interstitial regions disposed within the fourth region are substantially empty.

In one or more embodiments, polycrystalline diamond constructions as disclosed herein may include a substrate that is attached to the diamond body to form a polycrystalline diamond compact construction. In an example embodiment, the substrate may be attached to the diamond body adjacent the first region. The substrate that is ultimately attached to the diamond body may provide at least a portion of (for example, a major portion of) the infiltrant material and may be made from the same or different material as that which may have been used as a source of the catalyst material during the initial process of forming the diamond bonded matrix phase. Example substrate materials useful for providing the infiltrant material include those conventionally used to form PCD such as cermets, and in an example embodiment cemented tungsten carbide.

FIG. 4A schematically illustrates an infiltrant region 10 of a polycrystalline diamond construction prepared according to one or more embodiments of the present disclosure that includes the infiltrant material. Specifically, the region 10 includes a material microstructure comprising a plurality of bonded together diamond particles 12, forming an intercrystalline diamond matrix first phase, and the infiltrant material 14 that is disposed in the plurality of interstitial regions existing between the bonded together diamond particles and/or that are attached to the surfaces of the diamond particles. For purposes of clarity, it is understood that the region 10 of the polycrystalline construction is one taken from a PCD body after it has been modified in accordance with the present disclosure to: 1) remove the catalyst material that was used to initially form/sinter the PCD body; and 2) fill a population of the interstitial regions with an infiltrant material. If desired, the region 10 illustrated in FIG. 4A can be that of a filler region, wherein the material disposed within the interstitial regions is filler material rather than infiltrant material.

FIG. 4B schematically illustrates a thermally stable region 22 of a polycrystalline diamond construction prepared according to one or more embodiments of the present disclosure that is substantially free of any infiltrant material or filler material. Like the polycrystalline diamond construction region illustrated in FIG. 4A, the region 22 includes a material microstructure comprising the plurality of bonded together diamond particles 24, forming the intercrystalline diamond matrix first phase. Unlike the region 10 illustrated in FIG. 4A, this region of the diamond body 22 has been modified to remove any infiltrant material or filler material from the plurality of interstitial regions and, thus comprises a plurality of interstitial regions 26 that are substantially empty or free of the infiltrant material or the filler material. Again, it is understood that the region 22 of the polycrystalline diamond construction is one taken from a diamond body after it has been modified in accordance with the present disclosure to: 1) remove the catalyst material that was used to initially form the PCD body therefrom; 2) infiltrate the interstitial regions with infiltrant material or filler material; and 3) remove the infiltrant or filler material from the interstitial regions.

FIGS. 5A, 5B, and 5C each schematically illustrate an example embodiment polycrystalline diamond construction 30 as disclosed herein at different stages of formation. FIG. 5A illustrates a first stage of formation, starting with a conventional PCD body 32 in its initial form after sintering by conventional HPHT sintering process. At this early stage, the PCD body 32 comprises a polycrystalline diamond matrix phase and a solvent catalyst metal material, such as cobalt, used to form the diamond matrix phase and that is disposed within the interstitial regions between the bonded together diamond particles forming the matrix phase. The solvent metal catalyst material may be added to the precursor diamond grains or powder as a raw material powder prior to sintering, may be contained within the diamond grains or powder, or may be infiltrated into the diamond grains or powder during the sintering process from a substrate containing the solvent metal catalyst material and that is placed adjacent the diamond powder and exposed to the HPHT sintering conditions. In an example embodiment, the solvent metal catalyst material is provided from a substrate 34, e.g., a WC—Co substrate, during the HPHT sintering process.

Diamond grains useful for forming the PCD body include synthetic or natural diamond powders having an average diameter grain size in the range of from submicrometer in size to 100 micrometers, and more preferably in the range of from about 0.5 or sub micron to 80 micrometers. The diamond powder may contain grains having a mono or multi-modal particle size distribution. In the event that diamond powders are used having differently sized grains, the diamond grains are mixed together by conventional process, such as by ball or attrittor milling or dry mixing methods for as much time as necessary to ensure good uniform distribution. The PCD body may be formed from a single diamond powder or may be formed from multiple layers of diamond powders which may provide for a gradual or step-wise gradient in one or more properties within the sintered PCD body such as diamond density, average diamond grain size, catalyst material content, which can provide a desired change or level of strength and thermal abrasion properties.

As noted above, the diamond powder may be combined with a desired solvent metal catalyst powder to facilitate diamond bonding during the HPHT process and/or the solvent metal catalyst may be provided by infiltration from a substrate positioned adjacent the diamond powder during the HPHT process. Suitable solvent metal catalyst materials useful for forming the PCD body include those metals selected from Group VIII elements of the Periodic table. An example solvent metal catalyst is cobalt (Co).

The diamond powder mixture can be provided in the form of a green-state part or mixture comprising diamond powder that is contained by a binding agent, e.g., in the form of diamond tape or other formable/conformable diamond mixture product to facilitate the manufacturing process. In the event that the diamond powder is provided in the form of such a green-state part it is desirable that a preheating process take place before HPHT consolidation and sintering to drive off the binder material. In an example embodiment, the PCD body resulting from the above-described HPHT process may have a diamond volume content in the range of from about 85 to 95 percent. For certain applications, a higher diamond volume content up to about 98 percent may be desired.

The diamond powder or green-state part is loaded into a desired container for placement within a suitable HPHT consolidation and sintering device. In an example embodiment, where the source of the solvent metal catalyst material is provided by infiltration from a substrate, a suitable substrate material is disposed within the consolidation and sintering device adjacent the diamond powder mixture. In one or more embodiments, the substrate is provided in a preformed state. Substrates useful for forming the PCD body can be selected from the same general types of materials conventionally used to form substrates for conventional PCD materials, including carbides, nitrides, carbonitrides, ceramic materials, metallic materials, cermet materials and mixtures thereof. A feature of the substrate used for forming the PCD body is that it includes a solvent metal catalyst capable of melting and infiltrating into the adjacent volume of diamond powder to facilitate conventional diamond-to-diamond intercrystalline bonding during HPHT processing to form/sinter the PCD body. An example substrate material is cemented tungsten carbide (WC—Co).

Where the solvent metal catalyst is provided by infiltration from a substrate, the container including the diamond particles and the substrate is loaded into the HPHT device and the device is then activated to subject the container to a desired HPHT condition to effect consolidation and sintering of the diamond particles. In an example embodiment, the device is controlled so that the container is subjected to a HPHT process having a pressure of 5,000 MPa or more and a temperature of from about 1,350° C. to 1,500° C. for a predetermined period of time. At this pressure and temperature, the solvent metal catalyst melts and infiltrates into the diamond particles, thereby sintering the diamond grains to form conventional PCD.

While a particular pressure and temperature range for this HPHT process has been provided, it is to be understood that such processing conditions can and will vary depending on such factors as the type and/or amount of solvent metal catalyst used in the substrate, as well as the type and/or amount of diamond particles used to form the PCD body or region. After the HPHT sintering process is completed, the container is removed from the HPHT device, and the assembly comprising the bonded together PCD body and substrate is removed from the container. Again, it is to be understood that the PCD body may be formed without using a substrate if so desired.

The PCD body so formed may be of any appropriate thickness. In particular, the PCD body may have an average thickness (measured between the upper surface and lower surface) of at least about 1 mm, suitably at least about 1.5 mm, more suitably at least about 2 mm, for example in the range of from about 1.5 mm to about 5 mm, such as 2.25 mm, 2.5 mm, 2.75 mm, 3 mm, 3.25 mm, 3.5 mm or 4 mm.

PCD bodies useful for forming ultra-hard constructions as disclosed herein may include those formed at HPHT conditions, such as those disclosed in US 2010/0294571 A1, which is incorporated herein by reference. Such PCD bodies can be formed at higher pressures of approximately 5.4 GPa to 6.3 GPa (cold cell pressures), which correspond to approximately 6.2 GPa to 7.1 GPa as temperatures are increased past the cobalt/carbon eutectic line. In example embodiments, the pressure (at high temperature) is in the range of approximately 6.2 to 7.2 GPa. In various embodiments, the cell pressure (at high temperature) may be greater than 6.2 GPa, for example in the range of from greater than 6.2 GPa to 8 GPa or from 6.3 GPa to 7.4 GPa, such as 6.25 GPa, 6.35 GPa, 6.4 GPa, 6.45 GPa, 6.5 GPa, 6.6 GPa, or 6.7 GPa.

FIG. 5B schematically illustrates an example embodiment polycrystalline diamond construction 30 of the present disclosure after a second stage of formation, specifically at a stage where the solvent catalyst material used to initially form/sinter the diamond body and disposed in the interstitial regions and/or attached to the surface of the bonded together diamond particles has been removed from the diamond body 32. At this stage of making the construction, the PCD body has a material microstructure resembling region 22 that is illustrated in FIG. 4B, comprising the diamond matrix phase formed from a plurality of bonded together diamond particles 24, and interstitial regions 26 that are substantially free of the specific catalyzing material, e.g., cobalt, that was used during the sintering process to initially form the body of bonded diamond particles and that remains from that sintering process used to initially form the diamond matrix phase.

As used herein, the term “removed” is used to refer to the reduced presence of the specific material in the body, for example the reduced presence of the catalyst material that was used to initially form the diamond body during the HPHT sintering process, and is understood to mean that a substantial portion of the material (e.g., catalyst, infiltrant, and/or filler material) no longer resides within the region of the body. However, it is to be understood that some small trace amounts of the material may still remain in the microstructure of the region of the PCD body within the interstitial regions and/or adhered to the surface of the diamond particles.

Additionally, the term “substantially free,” as used herein to refer to the portion of the remaining diamond body after the specific material has been removed, is understood to mean that there may still be some trace/residual small amounts of the specific material remaining within the region of the body as noted above. In one or more embodiments, the body may be treated such that more than 98 percent by weight (% w), based on the total weight of the treated region, has had the material removed from the interstitial regions within the treated region, in particular at least 99% w, more in particular at least 99.5% w, same basis, may have had the material removed from the interstitial regions within the treated region. At most 2 percent by weight (% w), based on the total weight of the region of the PCD body, for example at most 1.5% w, 1% w, or 0.5% w, same basis, may remain.

For example, trace amounts of catalyst material may remain within the treated PCD body due to the catalyst material being trapped in the regions of diamond regrowth (diamond-to-diamond bonding) and is not necessarily removable by treatment methods such as chemical leaching. The quantity of the specific catalyst material used to form the diamond body remaining in the material microstructure after the diamond body has been subjected to treatment to remove the same can and will vary on such factors as the efficiency of the removal process, and the size and density of the diamond matrix material.

In an example embodiment, the catalyst material used to form the PCD body may be removed therefrom by a suitable process, such as by chemical treatment such as by acid leaching or aqua regia bath, electrochemically such as by electrolytic process, by liquid metal solubility technique, or by combinations thereof. In one or more embodiments, the catalyst material is removed by an acid leaching technique, such as that disclosed for example in U.S. Pat. No. 4,224,380, which is incorporated herein by reference.

Accelerating techniques for removing the catalyst material may also be used, and may be used in conjunction with the leaching techniques noted above as well as with other conventional leaching processing. Such accelerating techniques include elevated pressures, elevated temperatures and/or ultrasonic energy, and may be useful to decrease the amount of treatment time associated with achieving the same level of catalyst removal, thereby improving manufacturing efficiency.

In one embodiment, the leaching process may be accelerated by conducting the same under conditions of elevated pressure that may be greater than about 5 bar and that may range from about 10 to 50 bar in other embodiments. Such elevated pressure conditions may be achieved by conducting the leaching process in a pressure vessel or the like. It is to be understood that the exact pressure condition can and will vary on such factors as the leaching agent that is used as well as the materials and sintering characteristics of the diamond body.

In addition to elevated pressure, elevated temperatures may also be used for the purpose of accelerating the leaching process. Suitable temperature levels may be in the range of from about 90 to 350° C. in one embodiment, and up to 175 to 225° C. in another embodiment. In one or more embodiments, elevated temperature levels may range up to 300° C. It is to be understood that the exact temperature condition can and will vary on such factors as the leaching agent that is used as well as the materials and sintering characteristics of the diamond body. It is to be understood that the accelerating technique may include elevated pressure in conjunction with elevated temperature, which would involve the use of a pressure assembly capable of producing a desired elevated temperature, e.g., by microwave heating or the like. For example, a microwave-transparent pressure vessel may be used to implement the accelerated leaching process. The accelerating technique may include elevated temperature or elevated pressure, i.e., one or the other and not a combination of the two.

Ultrasonic energy may be used as an accelerating technique that involves providing vibratory energy operating at frequencies beyond audible sound, e.g., at frequencies of about 18,000 cycles per second and greater. A converter or piezoelectronic transducer may be used to form a desired ultrasonic stack for this purpose, wherein the piezoelectric crystals may be used to convert electrical charges to desired acoustic energy, i.e., ultrasonic energy. Boosters may be used to modify the amplitude of the mechanical vibration, and a sontotrode or horn may be used to apply the vibration energy. The use of ultrasonic energy may produce an 80 to 90 percent increase in leaching depth as a function of time as compared to leaching without using ultrasonic energy, thereby providing a desired decrease in leaching time and an improvement in manufacturing efficiency.

Referring again to FIG. 5B, at this stage of the process any substrate 34 that was used as a source of the catalyst material may be removed from the diamond body 32, and/or may fall away from the diamond body during the process of catalyst material removal. In an example embodiment, it may be desired to remove the substrate from the diamond body before treatment to facilitate the catalyst removal process, e.g., so that all surfaces of the diamond body may be exposed for the purpose of catalyst material removal. If the source of the catalyst material was provided by mixing with or otherwise providing with the precursor diamond powder, then the polycrystalline construction 30 at this stage of manufacturing will not contain a substrate, i.e., it will consist of a diamond body 32.

FIG. 5C schematically illustrates an example embodiment polycrystalline construction 30 prepared in accordance with the present disclosure after a third stage of formation. Specifically, at a stage where the catalyst material used to initially form the diamond body has been removed therefrom and has been replaced with a desired infiltrant material 38 and filler material 36. As noted above, the infiltrant material may be selected from the group of materials including metals, ceramics, cermets and combinations thereof. In an example embodiment, the infiltrant material is a metal, a mixture of metal or an alloy of metal. In one or more embodiments, the infiltrant material may be a metal or metal alloy selected from Group VIII of the Periodic table, such as cobalt, nickel, iron, combinations and alloys thereof. It is to be understood that the choice of material or materials used as the infiltrant material can and will vary depending on such factors including but not limited to the end-use application, and the type and density of the diamond grains used to form the polycrystalline diamond matrix first phase, and the mechanical properties and/or thermal characteristics desired for the polycrystalline diamond construction.

Referring back to FIG. 4B, once the catalyst material used to initially form the diamond body is removed from the diamond body, the remaining microstructure comprises a polycrystalline matrix phase with a plurality of interstitial voids 26 forming what is essentially a porous material microstructure. This porous microstructure not only lacks mechanical strength, but also lacks a material constituent that is capable of forming a strong attachment bond with a substrate, e.g., in the event that the polycrystalline diamond construction needs to be in the form of a compact comprising such a substrate to facilitate attachment to an end-use device.

A population of the voids or pores in the polycrystalline diamond body may be filled with the infiltrant material using a number of different techniques. Only a portion of the voids in the diamond body may be filled with the infiltrant material. In one or more embodiments, the infiltrant material may be introduced into the diamond body by liquid-phase sintering under HPHT conditions (infiltration process or re-bonding process). In such embodiments, the infiltrant material may be provided in the form of a sintered part or a green-state part that contains the infiltrant material and that is positioned adjacent one or more surfaces of the diamond body. The assembly may be placed into a container that is subjected to HPHT conditions sufficient to melt the infiltrant material within the sintered part or green-state part and cause it to infiltrate into the diamond body. In one or more embodiments, the source of the infiltrant material may be a substrate that will be used to form a compact from the polycrystalline diamond construction by attachment to the diamond body during the HPHT re-bonding process.

Rather than using a pre-formed substrate as a source of the infiltrant material, the diamond body may have a desired powder volume that is positioned adjacent one or more surfaces of the diamond body to provide the infiltrant material. In an example embodiment, the desired powder is a metal material containing the infiltrant material. In an example embodiment, the desired powder is formed from one or more materials that may be sintered to provide an element that is attached to the diamond body and that has desired properties to facilitate use of the resulting sintered polycrystalline diamond construction in a cutting and/or wear application, for example the powder mixture may comprise a WC—Co material. When subjected to HPHT conditions, the cobalt in such powder mixture melts and infiltrates into the diamond body. Instead of powder, the infiltrant material can be provided adjacent a surface of the diamond body in the form of a foil or disc or the like by chemical plating operations, by electroplating operations or the like, where the desired infiltrant material is deposited on the diamond body surface.

The term “filled,” as used herein to refer to the presence of the infiltrant material and/or filler material in the voids or pores of the diamond body that resulted from removing the catalyst material used to form the diamond body therefrom, is understood to mean that a substantial volume of such voids or pores contain the infiltrant material and/or filler material. It is understood that a population of the voids or pores of the diamond body within a particular region may remain substantially empty or partially filled due to non-uniform pore size, temperature gradients which may be present in the press cell or the composition of the substrate.

Another population of the voids or pores in the polycrystalline diamond body may be filled with the filler material using one or more of the techniques discussed above for introducing the infiltrant material into the PCD body. Only a portion of the voids in the diamond body may be filled with the filler material. In one or more embodiments, the filler material may be introduced into the diamond body by liquid-phase sintering under HPHT conditions (infiltration process or re-bonding process). In an example embodiment the filler material may be provided in the form of a pre-formed body, such as a ring, foil, disc, substrate and the like, or in the form of powder, by spray coating or by other deposition method capable of delivering the filler material to a desired surface of the diamond body. In an example embodiment, where the filler material is provided in the form of a pre-formed body, such body may be positioned adjacent one or more surfaces of the diamond body (e.g., working surfaces) after the metal catalyst material used to initially form the same has been removed. The amount of filler material introduced into the PCD body may be controlled by adjusting the size and shape of the pre-formed body.

The filler material may be introduced into the PCD body by placing a powder material containing the filler material adjacent one or more surfaces of the diamond body (e.g., working surfaces) after the metal catalyst material used to initially form the same has been removed. The amount of filler material introduced into the PCD body may be controlled by adjusting the quantity of powder material placed adjacent the PCD body.

The filler material may be introduced into the PCD body by a pressure technique where the filler material may be provided in the form of a slurry or the like comprising the desired filler material and a carrier, e.g., such as a polymer or organic carrier. The slurry may then be exposed to the diamond body (e.g., working surfaces) at high pressure to cause the slurry to enter the diamond body and cause the filler material to fill the voids therein. The PCD body may then be subjected to elevated temperature for the purpose of removing the carrier therefrom, thereby leaving the filler material disposed within the interstitial regions. The amount of filler material introduced into the PCD body may be controlled by adjusting the quantity of slurry material placed adjacent the PCD body.

In one or more embodiments, the filler material has a much lower melting temperature than the infiltrant material, for example the melting temperature of the filler material may be at most 700° C., at most 600° C., at most 400° C., at most 350° C., or at most 300° C. In an example embodiment, the filler material has a melting temperature that is less than that of the infiltrant material, at atmospheric conditions, for example by at least about 400° C., preferably by at least about 1,000° C., and more preferably by at least about 1,200° C.

In one or more embodiments, the filler material may be introduced into the PCD body prior to introducing the infiltrant material since the introduction of the filler material may take place at a temperature significantly below the thermal degradation temperature of the PCD body (filling process). The conditions during such a filling process may include pressures of at least at least 50 kbar, and at temperature of at least 150° C.

The filler material may be introduced into the PCD body during the same process utilized to infiltrate the PCD body with the infiltrant material (infiltrating process or re-bonding process). In this embodiment, the assembly includes the filler material positioned adjacent one or more surfaces of the PCD body (e.g., working surfaces).

The assembly containing the filler material (whether contained within the pores of the PCD body or adjacent a surface of the PCD body) and the infiltrant material is subjected to HPHT conditions sufficient to cause the infiltrant (e.g., cobalt from the substrate) to melt, infiltrate into, and fill a population of the voids or pores in the polycrystalline diamond matrix not already filled by the filler material.

A substrate used as a source for the infiltrant material may have a material make up and/or performance properties that are different from that of a substrate used to provide the catalyst material for the initial sintering of the diamond body. For example, the substrate selected for sintering the diamond body may comprise a material make up that facilitates diamond bonding, but that may have poor erosion resistance and as a result not be well suited for an end-use application in a drill bit. In this case, the substrate selected at this stage for providing the source of the infiltrant material may be selected from materials different from that of the sintering substrate, e.g., from materials capable of providing improved down hole properties such as erosion resistance when attached to a drill bit. Accordingly, it is to be understood that the substrate material selected as the infiltrant material source may be different from the substrate material used to initially sinter the diamond body.

In an example embodiment, wherein a PCD material is treated to remove the solvent metal catalyst material, e.g., cobalt, used to initially form the same therefrom, the resulting diamond body is subjected to a HPHT re-bonding process for a period of approximately 100 seconds at a temperature sufficient to meet the melting temperature of the infiltrant material, which is cobalt. The source of the cobalt infiltrant material is a WC—Co substrate that is positioned adjacent a desired surface portion of the diamond body prior to HPHT re-bonding processing. A filler material, e.g., tin (Sn), in the form of a foil is placed adjacent the upper surface of the treated PCD body. FIG. 6A illustrates a partial cross-sectional view (the surrounding can has been omitted for purposes of clarity) of an assembly prior to the re-bonding process. Substrate 634 is placed adjacent a lower surface 665 of the treated PCD body 610, and a pre-formed foil of the filler material 635 is placed adjacent an upper surface 664 of the treated PCD body 610.

The assembly is placed in an HPHT device, and the HPHT process is controlled to bring the contents to the melting temperature of cobalt (about 1,350° C., at a pressure of about 3,400 to 7,000 MPa) to enable the cobalt to infiltrate into and fill a population of pores or voids in the diamond body adjacent the substrate, and to enable the filler material to infiltrate into and fill another population of pores of voids in the diamond body adjacent the foil.

Referring to FIG. 1, the HPHT process is controlled to subject the sintered diamond body to different conditions identified in FIG. 1 as Regions 1, 2 and 3. Initially, the diamond body is subjected to a temperature sufficient to melt the filler material. In an example embodiment, this temperature is less than about 700° C., and is understood to vary depending on the particular filler material that is selected. The pressure within Region 1 may be above or below the Berman/Simon diamond-graphite equilibrium line, depending on the amount of pressure useful for causing the melted filler material to enter the diamond body. In an example embodiment, the filler material is infiltrated into the diamond body at a pressure of less than about 3 GPa. Thus, the pressure for Region 1 may be above or below the diamond-graphite equilibrium line depending on such factors as the interstitial pore sizes, and the type of filler material that is selected. In an example, the pressure in Region 1 may be about 1 GPa above the diamond-graphite equilibrium line, to ensure that the filler material infiltrates into the diamond body. Thus, within Region 1 of the HPHT process, the filler material melts and is infiltrated into the diamond body to form a filler region as described above. In an example embodiment within Region 1, when the filler material melts and the process is at an appropriate pressure, the filler material infiltrates and sweeps into the diamond body within a very short time, e.g., within a fraction of a second. The rate of infiltration may be controlled depending on how aggressive the heat ramp is set within Region 1. In such example embodiment, the filler infiltration into the diamond body stabilizes over a period of from about 30 to 600 seconds.

Subsequently, the HPHT process is controlled to progress from Region 1 to Region 2 by increasing the temperature and pressure exerted on the diamond body now containing the filler region. In an example embodiment, the temperature in Region 2 is increased from about 700° C. to a temperature that is below the melting point of the infiltrant material, e.g., for cobalt, less than about 1,350° C. In Region 2, the pressure during the HPHT process is also increased for the purpose of transitioning from Region 1 to cause the infiltrant material to be melted and infiltrate into the diamond body within Region 3.

In an example embodiment, the pressure in Region 2 may be above or below (as illustrated in Region 2a) the diamond-graphite equilibrium line, depending on the particular pressure exerted in Region 1. In an example embodiment, the pressure in Region 2 is about 1 GPa above the diamond-graphite equilibrium line to stay within the diamond stable region during a simultaneous pressure and temperature ramp and provide some operating window to account for cell to cell variation. However, when using filler materials that do not require pressurization into the diamond stable region (above the diamond-graphite equilibrium line) for infiltration in Region 1, it may be advantageous to simply ramp quickly through at least a portion of Region 2a below the diamond-graphite equilibrium line on the way to Region 3 to minimize any extreme transition.

Within Region 2, the diamond body, comprising the filler region, is subjected to increasing pressure and temperature as it approaches Region 3. A feature of the controlled HPHT process and use of the filler material as disclosed herein, is that the presence of the so-formed diamond body filler region operates to keep the diamond body in an isostatic condition within in the diamond stable region as the pressure is increased (in Regions 2 and 3), thereby minimizing the possibility of the diamond bonds being broken and/or the diamond structure being damaged with increasing pressure.

As the HPHT process is continued, it reaches Region 3 wherein the temperature is increased to an amount sufficient to melt the infiltrant material. The pressure in Region 3 is controlled to be at or above the Berman/Simon diamond-graphite equilibrium line to keep the diamond body in the diamond stable region or state. In Region 3, the melted infiltrant material infiltrates under pressure into the diamond body forming an infiltrant region to fill the interstitial regions or pores within such region. In Region 3, the filler region operates together with the infiltrant region to keep the entire diamond body in an isostatic condition within the diamond stable region or state, thereby minimizing or eliminating the possibility of the diamond body sustaining structural damage during the HPHT process, which damage could otherwise well occur due to the presence of a sufficient amount of unfilled interstitial regions or pores. During the HPHT re-bonding process, the substrate containing the infiltrant material, e.g., cobalt, is attached to the diamond body to thereby form a polycrystalline diamond compact construction. The cobalt from the substrate is the sole source of infiltrant material.

In an example embodiment, it is desired that the diamond body comprises a filler region and an infiltrant region that together operate to reduce the population of unfilled interstitial regions within the diamond body during HPHT conditions when in Region 3 to less than about 2 percent to maintain the diamond body in a desired diamond-stable state and protect it against undesired damage to the diamond structure. In an example embodiment, the population of unfilled interstitial regions within the diamond body during HPHT processing in Region 3 may be from about 0 to 2 percent, preferably be from about 0 to 1 percent, and most preferably be 0, or 100 percent of the interstitial regions within the diamond body are filled (with either the filler material and/or the infiltrant material) when the diamond body is subjected to the HPHT processing conditions of Region 3.

FIG. 6B illustrates a cross-sectional view of a re-bonded PCD compact construction after infiltration of the infiltrant and filler materials. The infiltrated PCD body 611 contains a filler region 633 and infiltrated region 622. The infiltrated region 622 is located adjacent the substrate, extending a depth into the body from the substrate, and the filler region 633 extends a depth into the body from a surface opposite the substrate. The major portion of the filler region 633 has interstitial regions/pores filled with filler material consisting of tin. The major portion of the infiltrant region 622 has interstitial regions/pores filled with infiltrant material. While the interface between the region 633 and 622 has been illustrated as being straight or planar, it is to be understood that the interface configuration can and will vary depending on such factors as the thickness, size and/or shape of the filler material source, and/or the heating balance in the cell. In some embodiments the interface can be nonplanar in cross section, e.g., concave or convex.

While the PCD compact construction illustrated in FIG. 6B depicts the diamond body 611 bonded directly to the substrate 634, it is to be understood that PCD constructions as disclosed herein may include one or more transition layer interposed between the diamond body and the substrate. In an example embodiment, such transition layer may be used to provide a transition in one or more properties between the diamond body and substrate. In an example embodiment, the transition layer may be used to provide a transition in the thermal expansion characteristics between the diamond body and the substrate, wherein such transition layer may have a diamond content that is less than that of the diamond body and preferably within between about 80 to 95 wt %.

In an example embodiment, subsequent to the HPHT re-bonding process, the PCD construction illustrated in FIG. 6B is subsequently treated to remove the filler material therefrom. If desired, all or a portion of the infiltrant material can also be removed during the same or different treatment. In an example embodiment, the filler material is removed from the filler region, and infiltrant material is leached from a portion of the infiltrant region to thereby form a thermally stable region adjacent: 1) the entire upper surface; 2) the entire cutting edge; and 3) a portion of the length of the side surface of the PCD body (including the entire circumferential distance of the side surface).

As illustrated in FIG. 6C, a cross-sectional view of the PCD compact shows the thermally stable region 644 (that is substantially free of the filler and infiltrant materials) as extending a depth from the top and side surfaces, and the remaining infiltrated region 655 extending to the substrate 634. The particular embodiment illustrated in FIG. 6C shows thermal region having a depth, as measured from the diamond body top surface, that is greater near the circumferential edge than near the middle, the depth decreases moving radially inwardly from the side surfaces towards the center. This is understood as being but one embodiment illustrating a configuration of the thermally stable region and that configurations other than that disclosed and illustrated are intended to be within the scope of the PCD constructions as disclosed herein.

It is advantageous to utilize a low-melting temperature filler material as described herein because such material readily infiltrates and sweeps through and into the pores of the treated PCD body at temperatures and pressures, i.e., during an HPHT process, that are much lower than those necessary for introducing the infiltrant into the PCD body. Thus, upon subsequent infiltration of the infiltrant, which occurs at higher temperatures and pressures during the HPHT process, the interstitial regions or pores of the treated PCD body are sufficiently filled with either the filler material or the infiltrant to ensure that the treated PCD body remain in the diamond stable region, i.e., above the Berman/Simon diamond-graphite equilibrium line, during infiltration of the infiltrant. This operates to protect and prevent regions of the PCD body from being damaged or otherwise converted to from diamond to graphite, essentially providing a PDC body capable of maintaining an isostatic condition during HPHT processing to resist structural failures otherwise known to occur with conventional PCD bodies subjected to conventional HPHT processes.

Additionally, the filler materials selected are those that can more easily migrate and infiltrate into the small pores of the treated PCD body then conventional infiltrants, thereby permitting a deeper level of infiltration into the PCD body than otherwise possible using conventional infiltrants. Further, such filler materials can also be more easily removed from the small pores of the re-infiltrated PCD body, thereby allowing for the creation of a deeper thermally stable region within the PCD body once removed, than practically permissible using conventional infiltrants materials.

Techniques useful for removing infiltrant or filler material from the diamond body include the same ones described above for removing the catalyst material used to initially form the diamond body, e.g., such as by acid leaching or the like. In an example embodiment, it is desired that the process of removing the filler material and optionally the infiltrant material be controlled so that the material be removed from a targeted region of the diamond body extending a determined depth from one or more diamond body surfaces. These surfaces may include working and/or nonworking surfaces of the diamond body.

In one or more embodiments, the filler material and optionally the infiltrant material may be removed from the diamond body to any suitable depth. In one or more embodiments, the filler material and optionally the infiltrant material may be removed from the diamond body to a depth of at most about 2 mm from the desired surface or surfaces. In one or more embodiments, the filler material and optionally the infiltrant material may be removed from the diamond body to a depth of at least about 0.01 mm from the desired surface or surfaces. For example, the filler material and optionally the infiltrant material may be removed from the diamond body to a depth in the range of from about 0.01 mm to about 2 mm from the desired surface or surfaces, in particular from about 0.05 mm to about 1.5 mm or from about 0.1 mm to about 1 mm, such as 0.75 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm or 0.95 mm. Suitably, a depth of at least about 0.3 mm may be used in one or more embodiments. Ultimately, the specific depth of the region formed in the diamond body by removing the filler material and optionally the infiltrant material will vary depending on the thickness of the PCD body and the particular end-use application.

In the embodiments where a portion of the filler material is removed from the PCD body, the filler material may be any material capable of filling a population of pores within the treated PCD body and which has a melting temperature that is lower than the infiltrant material. Suitably, such filler materials may be selected from aluminum, gallium, copper, zinc, silver, indium, thallium, tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from aluminum, gallium, indium, thallium, tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from tin, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may consist of tin, bismuth and alloys thereof. In an example embodiment, the filler material may consist of tin and alloys thereof. In an example, the filler material may comprise 95-99% pure tin.

In the embodiments where the filler material is not removed from the PCD body, the filler material has a melting temperature that is lower than the infiltrant material and may be selected from aluminum, gallium, zinc, indium, thallium, tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from aluminum, gallium, indium, thallium, tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from tin, lead, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may be selected from tin, bismuth, alloys and mixtures thereof. In an example embodiment, the filler material may consist of tin, bismuth, and alloys thereof. In an example embodiment, the filler material may consist of tin and alloys thereof.

In an example embodiment, the substrate used to form the polycrystalline diamond compact construction is formed from a cermet material, such as that conventionally used to form a PCD compact. In an example, when the substrate is used as the source of the infiltrant material, the substrate may be formed from a cermet, such as a tungsten carbide (WC), further comprising a binder material that is the infiltrant material used to fill a population of the pores within the diamond body. Suitable binder materials include Group VIII metals of the Periodic table or alloys thereof, and/or Group IB metals of the Periodic table or alloys thereof, and/or other metallic materials having a melting temperature that is greater than the filler material.

In addition to the materials disclosed above, the filler material can be selected from salts, e.g., metal salts, and carbonates. Examples include alkali carbonates, alkaline earth carbonates, fluorides, chlorides, bromides, sulfides and combinations thereof, which alone or when combined have melting points below that of the infiltrant material, e.g., cobalt, under HPHT conditions. Examples include Na2CO3, K2CO3, Na2CO3+K2CO3, MgCO3, CaCO3, LiCl, NaCl, KCl, Na2CO3-graphite, NaCl—KCl, LiCl—NaCl—KCl, and combinations and mixtures thereof. It is to be understood that the examples provided herein are only representative of the different types of metal salts, carbonates, fluorides, chlorides, bromides, sulfides and combinations thereof that can be used to form filler materials as disclosed herein.

Although a substrate may be attached to the diamond body during the infiltrant material introduction, it is also understood that the substrate may be attached to the diamond body after the desired infiltrant material has been introduced. In such case, the infiltrant material may be introduced into the diamond body by a HPHT process that does not use the substrate material as a source, and the desired substrate may be attached to the diamond body by a separate HPHT process or other method, such as by brazing, welding or the like. The substrate may be attached to the diamond body before or after the filler material and optionally infiltrant material have been removed therefrom.

If desired, an intermediate or transition material may be interposed between the substrate and the diamond body. The intermediate material may be formed from those materials that are capable of forming a suitable attachment bond between both the diamond body and the substrate. Suitable intermediate materials may include cermet materials comprising a Group VIII metal such as WC—Co, WC—Co alloy, or the like. The intermediate material may be provided as a powder or a partially sintered pre-form. The intermediate material may additionally include diamond particles forming a transition layer between the PCD body and the substrate.

Although the interface between the diamond body and the substrate illustrated in FIG. 6C is shown as having a planar geometry, it is understood that this interface may also have a nonplanar geometry, e.g., having a convex configuration, a concave configuration, or having one or more surface features that project from one or both of the diamond body and substrate. Such a nonplanar interface may be desired for the purpose of enhancing the surface area of contact between the attached diamond body and substrate, and/or for the purpose of enhancing heat transfer therebetween, and/or for the purpose of reducing the degree of residual stress imposed on the diamond body.

Further, polycrystalline diamond constructions of the present disclosure may comprise a diamond body having properties of diamond density and/or diamond grain size that may change as a function of position within the diamond body. For example, the diamond body may have a diamond density and/or a diamond grain size that changes in a gradient or step-wise fashion moving away from a working surface of the diamond body. Further, rather than being formed as a single mass, the diamond body used in forming polycrystalline diamond constructions as disclosed herein can be provided in the form of a composite construction formed from a number of diamond bodies that have been combined together, wherein each such body can have the same or different properties such as diamond grain size, diamond density, or the like

Polycrystalline diamond constructions the various embodiments of the present disclosure display marked improvements in thermal stability and thus service life when compared to conventional PCD constructions. Polycrystalline diamond constructions of the present disclosure may be used to form wear and/or cutting elements in a number of different applications such as the automotive industry, the oil and gas industry, the aerospace industry, the nuclear industry, and the transportation industry to name a few. Polycrystalline diamond constructions of the present disclosure are well suited for use as wear and/or cutting elements that are used in the oil and gas industry in such application as on drill bits used for drilling subterranean formations.

FIG. 7 illustrates an embodiment of a polycrystalline diamond compact construction as disclosed here provided in the form of an insert 70 used in a wear or cutting application in a roller cone drill bit or percussion or hammer drill bit used for subterranean drilling. For example, such inserts 70 can be formed from blanks comprising a substrate 72 formed from one or more of the substrate materials 73 disclosed above, and a diamond body 74 having a working surface 76 comprising a material microstructure prepared in accordance with one or more embodiments of the present disclosure. The blanks are pressed or machined to the desired shape of a roller cone rock bit insert.

Although the insert in FIG. 7 is illustrated having a generally cylindrical configuration with a rounded or radiused working surface, it is to be understood that inserts formed from polycrystalline constructions of the present disclosure configured other than as illustrated and such alternative configurations are understood to be within the scope of the present disclosure.

FIG. 8 illustrates a rotary or roller cone drill bit in the form of a rock bit 78 comprising a number of the wear or cutting inserts 70 disclosed above and illustrated in FIG. 7. The rock bit 78 comprises a body 80 having three legs 82, and a roller cutter cone 84 mounted on a lower end of each leg. The inserts 70 may be fabricated according to the method described above. The inserts 70 are provided in the surfaces of each cutter cone 84 for bearing on a rock formation being drilled.

FIG. 9 illustrates the inserts 70 described above as used with a percussion or hammer bit 86. The hammer bit comprises a hollow steel body 88 having a threaded pin 90 on an end of the body for assembling the bit onto a drill string (not shown) for drilling oil wells and the like. A plurality of the inserts 70 is provided in the surface of a head 92 of the body 88 for bearing on the subterranean formation being drilled.

FIG. 10 illustrates a polycrystalline construction compact of the present disclosure embodied in the form of a shear cutter 94 used, for example, with a drag bit for drilling subterranean formations. The shear cutter 94 comprises a diamond body 96, prepared in accordance with one or more embodiments of the present disclosure. The body is attached to a cutter substrate 98. The PCD body 96 includes a working or cutting surface 100.

Although the shear cutter in FIG. 10 is illustrated having a generally cylindrical configuration with a flat working surface that is disposed perpendicular to a longitudinal axis running through the shear cutter, it is to be understood that shear cutters formed from polycrystalline diamond constructions of the present disclosure may be configured other than as illustrated and such alternative configurations are understood to be within the scope of the present disclosure.

FIG. 11 illustrates a drag bit 102 comprising a plurality of the shear cutters 94 described above and illustrated in FIG. 10. The shear cutters are each attached to blades 104 that each extend from a head 106 of the drag bit for cutting against the subterranean formation being drilled.

One of ordinary skill in the art should appreciate after learning the teachings of the present disclosure that various other tools may use the cutting elements of the present disclosure. Such tools may include reamers, stabilizers, hole openers, down hole tool sleeves (which may be welded to a bit).

Other modifications and variations of polycrystalline diamond bodies, constructions, compacts, and methods of forming the same according to the principles of the present disclosure will be apparent to those skilled in the art. For example in the present disclosure, embodiments may refer to diamond or polycrystalline diamond; however, it is intended such embodiments may also include ultra-hard materials generally. For example, the cutting edge may be depicted as having a sharp edge between the top surface and side surface of the PCD body; however, such cutting edge may also be a beveled cutting edge having a bevel angle from 20 to 80 degrees. For example, two or more filler materials may be used in forming the polycrystalline ultra-hard construction of the present disclosure.

While polycrystalline ultra-hard constructions and methods of making the same have has been described with respect to a limited number of embodiments, those skilled in the art having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the polycrystalline ultra-hard constructions and methods of making the same as disclosed herein. Accordingly, the scope of polycrystalline ultra-hard constructions and methods of making the same as disclosed herein should be limited only by the attached claims.

Claims

1. A method for making an ultra-hard polycrystalline construction comprising:

subjecting a sintered ultra-hard body that is substantially free of a catalyst material used to initially sinter the ultra-hard body at high pressure/high temperature conditions to a further high pressure/high temperature process to introduce an infiltrant material, wherein the sintered ultra-hard body comprises a matrix phase of directly bonded together ultra-hard particles, and a plurality of substantially empty interstitial regions disposed within the matrix, wherein the further high pressure/high temperature process comprises:
melting and infiltrating a filler material into the sintered ultra-hard body to form a filler region having interstitial regions filled with the filler material, the filler region extending a partial depth into the sintered ultra-hard body and being formed at a temperature below the melting temperature of an infiltrant material and at a pressure below about 3 GPa; and
melting and infiltrating the infiltrant material into the sintered ultra-hard body to form an infiltrant region, wherein melting and infiltrating the infiltrant material occurs at a temperature and pressure greater than that used to form the filler region, and wherein the infiltrant region extends a partial depth into the sintered ultra-hard body.

2. The method as recited in claim 1, wherein the filler material has a melting temperature of less than about 1,000° C.

3. The method as recited in claim 1, wherein after melting and infiltrating the infiltrant material, the sintered ultra-hard body consists of the filler region and infiltrant region.

4. The method as recited in claim 1, wherein during melting and infiltrating the infiltrant material, a sufficient population of the interstitial regions within the sintered ultra-hard body are filled with either the filler material or the infiltrant material such that the sintered ultra-hard body remains above the Berman/Simon diamond-graphite equilibrium line.

5. The method as recited in claim 1, wherein after melting and infiltrating the infiltrant material less than about 2 percent of the population of the interstitial regions within the sintered ultra-hard body are empty.

6. The method as recited in claim 1, wherein after melting and infiltrating the infiltrant material about 0 to 2 percent of the population of the interstitial regions within the sintered ultra-hard body are empty.

7. The method as recited in claim 6, wherein after melting and infiltrating the infiltrant material about 0 to 1 percent of the population of the interstitial regions within the sintered ultra-hard body are empty.

8. The method as recited in claim 6, wherein after melting and infiltrating the infiltrant material essentially 100 percent of the interstitial regions are filled.

9. The method as recited in claim 1, further comprising attaching a substrate to the ultra-hard body.

10. The method as recited in claim 9, wherein the substrate is attached to the body adjacent the body infiltrant region.

11. The method as recited in claim 1, wherein the filler material is selected from the group consisting of aluminum, gallium, copper, zinc, silver, indium, thallium, tin, lead, bismuth, alloys, metal salts, and mixtures thereof.

12. The method as recited in claim 1, wherein the filler material is selected from the group consisting of metal salts, carbonates, fluorides, chlorides, bromides, sulfides and combinations thereof.

13. The method as recited in claim 11, wherein the filler material is an alloy which is a eutectic alloy.

14. The method as recited in claim 1, wherein the filler material comprises tin or bismuth.

15. The method as recited in claim 1, wherein the melting temperature of the filler material is less than about 700° C.

16. The method as recited in claim 1, wherein the melting temperature of the filler material is less than about 300° C.

17. The method as recited in claim 1, further comprising, after melting and infiltrating the infiltrant material, treating the ultra-hard body to remove the filler material from the filler region to provide a thermally stable region.

18. The method as recited in claim 17, wherein the thermally stable region contains less than about 12 percent by weight filler material, based on the total weight of the ultra-hard body.

19. The method as recited in claim 17, wherein the thermally stable region contains less than about 2 percent by weight filler material, based on the total weight of the ultra-hard body.

20. The method as recited in claim 1, wherein substantially all the ultra-hard particles in the ultra-hard body are directly bonded to one another.

21. The method as recited in claim 1, further comprising placing the filler material adjacent a working surface of the ultra-hard body before melting and introducing the filler material.

22. The method as recited in claim 9, wherein the infiltrant material is provided from the substrate.

23. The method as recited in claim 1, wherein the infiltrant material comprises one or more Group VIII elements of the Periodic table, alloys, and mixtures thereof.

24. The method as recited in claim 1, wherein the infiltrant material and the catalyst material are different.

25. The method as recited in claim 24, wherein the infiltrant material and the catalyst material both comprise cobalt.

26. The method as recited in claim 1, wherein the ultra-hard material is diamond, and the matrix phase is intercrystalline bonded together diamond crystals.

27. The method as recited in claim 1, wherein during melting and infiltrating the infiltrant material, a substrate is used as a source to introduce the infiltrant material, wherein the substrate is different from a substrate used to introduce the catalyst material initially used to sinter the ultra-hard body.

28. The method as recited in claim 27, wherein the substrate used as a source for the infiltrant material has a material makeup that is different from the substrate used to introduce the catalyst material.

29. The method as recited in claim 17, wherein the thermally stable region extends a depth of at least about 0.5 mm from a surface of the ultra-hard body including one or both of a top and side surface.

30. The method as recited in claim 17, further comprising treating the ultra-hard body to remove a portion of the infiltrant material so that the thermally stable region includes a portion of the infiltrant region.

31. A polycrystalline ultra-hard construction disposed in a high pressure/high temperature device, the construction comprising:

a sintered ultra-hard body having a material microstructure comprising a matrix phase of directly bonded together ultra-hard particles formed at high pressure/high temperature conditions in the presence of a catalyst material, the ultra-hard body having a surface and including interstitial regions disposed within the matrix phase, wherein the interstitial regions within the ultra-hard body are substantially free of the catalyst material;
wherein the ultra-hard body is at a temperature and pressure sufficient to melt and infiltrate a filler material into the ultra-hard body to form a filler region, wherein the pressure is less than about 3 GPa, the interstitial regions within the filler region comprising the filler material, and wherein the remaining interstitial regions in the ultra-hard body are substantially free of the filler material and the catalyst material; and
an infiltrant material positioned adjacent the ultra-hard body, wherein the infiltrant material is in a solid state at the pressure and temperature.

32. The construction as recited in claim 31, wherein the filler material is selected from the group consisting of aluminum, gallium, zinc, indium, thallium, tin, lead, bismuth, alloys, metal salts, and mixtures thereof, wherein the filler region extends into the ultra-hard body a depth from the surface.

33. The construction as recited in claim 31, wherein the temperature is less than about 700° C.

34. The construction as recited in claim 31, wherein the pressure is less than about 2.5 GPa.

35. A polycrystalline diamond construction comprising an ultra-hard body having a thermally stable region and an infiltrant region that is formed by the process comprising;

subjecting a sintered ultra-hard body to a high pressure/high temperature process, the sintered ultra-hard body comprising a matrix phase of intercrystalline bonded together diamond crystals that extends throughout the body, the body including a plurality of interstitial regions disposed within the matrix phase, wherein the interstitial regions are substantially free of a catalyst material that was used to initially form the sintered ultra-hard body, the high pressure/high temperature process comprises;
melting and infiltrating a filler material at a first temperature and first pressure condition to form a filler region in the ultra-hard body, wherein the interstitial regions within the filler region comprise the filler material, the first pressure condition being less than about 3 GPa, the filler region extending into the ultra-hard body a partial depth from an ultra-hard body first surface;
melting and infiltrating an infiltrant material at a second temperature and second pressure condition to form an infiltrant region in the ultra-hard body, wherein the interstitial regions within the infiltrant region comprise the infiltrant material, the second temperature condition being greater than the first temperature condition, and the second pressure condition being greater than the first pressure condition, wherein the ultra-hard body comprising the filler region and the infiltrant region at the second temperature and second pressure condition is in a diamond stable state above the Berman/Simon diamond-graphite equilibrium line; and
treating the ultra-hard body comprising the filler region and infiltrant region to remove the filler material from a population of the interstitial regions within the filler region to form a thermally-stable region that is substantially free of the filler material, and that extends a depth from the ultra-hard body surface.

36. The construction as recited in claim 35, wherein the ultra-hard body comprises the infiltrant region and the thermally stable region, and is substantially free of the filler region.

37. The construction as recited in claim 36, wherein the thermally stable region extends a depth into the infiltrant region, wherein the interstitial regions within the thermally stable region are substantially free of the infiltrant material.

38. The construction as recited in claim 35, wherein the filler material is an alloy which is a eutectic alloy.

39. The construction as recited in claim 35, wherein the filler material comprises tin or bismuth.

40. The construction as recited in claim 35, wherein the melting temperature of the filler material is less than about 700° C.

41. The construction as recited in claim 35, wherein the melting temperature of the filler material less than about 300° C.

42. The construction as recited in claim 35, wherein the infiltrant material comprises one or more Group VIII elements of the Periodic Table, alloys, and mixtures thereof.

43. The construction as recited in claim 35, wherein the infiltrant material and the catalyst material are different.

44. The construction as recited in claim 43, wherein the infiltrant material and the catalyst material both comprise cobalt.

45. The construction as recited in claim 35, wherein the surface comprises a working surface including a top surface and a side surface of the ultra-hard body, and wherein the thermally stable region extends a depth of at least about 0.5 mm from both the top and side surfaces.

46. The construction as recited in claim 45, further comprising a beveled cutting edge interposed between the top and side surfaces, and wherein the thermally stable region extends a depth therefrom.

47. The construction as recited in claim 35, further comprising a substrate attached to the ultra-hard body adjacent the infiltrant region.

48. The construction as recited in claim 35, wherein the ultra-hard body has a thickness of greater than about 1 mm.

49. A method for making an ultra-hard polycrystalline construction comprising:

subjecting a plurality of ultra-hard particles to a high pressure/high temperature condition in the presence of a catalyst material to form a polycrystalline ultra-hard material comprising a matrix phase of directly bonded together ultra-hard particles, and a plurality of interstitial regions disposed within the matrix phase which include the catalyst material;
treating the polycrystalline ultra-hard material to remove the catalyst material therefrom to form an ultra-hard body that is substantially free of the catalyst material used to initially form the polycrystalline ultra-hard material;
introducing a filler material, wherein the filler material fills a population of the plurality of interstitial regions of the ultra-hard body in a first region extending a depth from a surface of the ultra-hard body, wherein the first region is formed at a first temperature and at a pressure of less than about 3 GPa;
introducing an infiltrant material into the ultra-hard body comprising the first region at a temperature greater than the first temperature, wherein the infiltrant material fills a population of the plurality of interstitial regions of the ultra-hard body in a second region, wherein the second region is formed while the ultra-hard body is in a diamond stable state above the Berman/Simon diamond-graphite equilibrium line; and
attaching a substrate to the ultra-hard body.

50. The method of claim 49, further, comprising treating the ultra-hard body to remove at least a portion of the filler material therefrom to form a thermally stable region that is substantially free of the filler material.

51. The method of claim 50, further comprising treating the ultra-hard body to remove at least a portion of the infiltrant material therefrom to form the thermally stable region that is substantially free of the infiltrant material.

52. The method as recited in claim 49, wherein the thermally stable region extends a depth of less than about 0.2 mm from the surface.

53. The method as recited in claim 49, wherein the filler material is selected from the group consisting of aluminum, gallium, zinc, indium, thallium, tin, lead, bismuth, carbonates, sulfates, hydroxides, chlorides, alloys, metal salts, and mixtures thereof.

Patent History
Publication number: 20130152480
Type: Application
Filed: Dec 19, 2012
Publication Date: Jun 20, 2013
Applicant: SMITH INTERNATIONAL, INC. (HOUSTON, TX)
Inventor: SMITH INTERNATIONAL, INC. (HOUSTON, TX)
Application Number: 13/720,714
Classifications
Current U.S. Class: Impregnating Or Coating An Abrasive Tool (51/295); With Inorganic Material (51/307); Metal Or Metal Oxide (51/309)
International Classification: B24D 18/00 (20060101);