WO2016065018A1

WO2016065018A1 - Polycrystalline diamond-metal composite structures and method of manufacture

Info

Publication number: WO2016065018A1
Application number: PCT/US2015/056685
Authority: WO
Inventors: Stewart Middlemiss
Original assignee: Smith International, Inc.
Priority date: 2014-10-22
Filing date: 2015-10-21
Publication date: 2016-04-28

Abstract

A method of manufacturing a polycrystalline diamond construction includes placing diamond powder in a reaction container, placing a layer of a ceramic powder or an inert metal having a melting temperature greater than 1600°C in powdered form on top of the diamond powder in the reaction container, the layer of the ceramic powder or inert metal powder extending across the entire inner diameter of the reaction container, placing additional diamond powder on top of the layer of ceramic powder or inert metal powder in the reaction container, placing a substrate material into the reaction container on top of the additional diamond powder, and subjecting the reaction container and its contents to high temperature, high pressure sintering conditions.

Description

POLYCRYSTALLINE DIAMOND-METAL COMPOSITE STRUCTURES AND METHOD OF MANUFACTURE

CROSS REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 62/067,359, entitled " POLYCRYSTALLINE DIAMOND -METAL COMPOSITE STRUCTURES AND METHOD OF MANUFACTURE," filed October 22, 2014, the disclosure of which is hereby incorporated herein by reference.

BACKGROUND

[0002] Polycrystalline diamond ("PCD") materials and PCD elements formed therefrom are well known in the art. Conventional PCD may be formed by subjecting diamond particles in the presence of a suitable solvent metal catalyst material to processing conditions of high pressure/high temperature (HPHT), where the solvent metal catalyst promotes desired intercrystalline diamond-to-diamond bonding between the particles, thereby forming a PCD structure. The resulting PCD structure produces enhanced properties of wear resistance and hardness, making such PCD materials extremely useful in aggressive wear and cutting applications where high levels of wear resistance and hardness are desired.

[0003] FIG. 1 illustrates a microstructure of conventionally formed PCD material 10 comprising a plurality of diamond grains 12 that are bonded to one another to form an intercrystalline diamond matrix first phase. The catalyst/binder material 14, e.g., cobalt, used to facilitate the diamond-to-diamond bonding that develops during the sintering process is dispersed within the interstitial regions formed between the diamond matrix first phase. The term "particle" refers to the powder employed prior to sintering a superabrasive material, while the term "grain" refers to discernable superabrasive regions subsequent to sintering, as known and as determined in the art.

[0004] The catalyst/binder material used to facilitate diamond-to-diamond bonding can be provided generally in two ways. The catalyst/binder can be provided in the form of a raw material powder that is pre -mixed with the diamond particles or grit prior to sintering. Alternatively, the catalyst/binder can be provided by infiltration into the diamond material (during high temperature/high pressure processing) from an underlying substrate material that the final PCD material is to be bonded to. After the catalyst/binder material has facilitated the diamond-to-diamond bonding, the catalyst/binder material is generally distributed throughout the diamond matrix within interstitial regions formed between the bonded diamond grains. Particularly, as shown in FIG. 1, the binder material 14 is not continuous throughout the microstructure in the conventional PCD material 10. Rather, the microstructure of the conventional PCD material 10 may have a uniform distribution of binder among the PCD grains. Thus, crack propagation through conventional PCD material will often travel through the less ductile and brittle diamond grains, either transgranularly through diamond grain/binder interfaces 15, or intergranularly through the diamond grain/diamond grain interfaces 16.

[0005] Solvent catalyst materials may facilitate diamond intercrystalline bonding and bonding of PCD layers to each other and to an underlying substrate. Solvent catalyst materials typically used for forming conventional PCD include metals from Group VIII of the Periodic table, such as cobalt, iron, or nickel and/or mixtures or alloys thereof, with cobalt being the most common. Conventional PCD may comprise from 85 to 95% by volume diamond and a remaining amount of the solvent catalyst material. However, while higher metal content typically increases the toughness of the resulting PCD material, higher metal content also decreases the PCD material hardness, thus limiting the flexibility of being able to provide PCD layers having desired levels of both hardness and toughness. Additionally, when variables are selected to increase the hardness of the PCD material, typically brittleness also increases, thereby reducing the toughness of the PCD material.

SUMMARY

[0006] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. [0007] In one aspect, embodiments of the present disclosure relate to a method of manufacturing a polycrystalline diamond construction that includes placing diamond powder in a reaction container, placing a layer of a ceramic powder or an inert metal having a melting temperature greater than 1600°C in powdered form on top of the diamond powder in the reaction container, the layer of the ceramic material or inert metal extending across the entire inner diameter of the reaction container, placing additional diamond powder on top of the layer of ceramic powder or inert metal powder in the reaction container, placing a substrate material into the reaction container on top of the additional diamond powder, and subjecting the reaction container and its contents to high temperature, high pressure sintering conditions.

[0008] In another aspect, embodiments of the present disclosure relate to a method of manufacturing a polycrystalline diamond construction that includes placing diamond powder in a reaction container, placing a layer of an inert metal having a melting temperature greater than 1600°C in powdered form on top of the diamond powder in the reaction container, placing additional diamond powder on top of the layer of inert metal in the reaction container, placing a substrate material into the reaction container on top of the additional diamond powder, and subjecting the reaction container and its contents to high temperature, high pressure sintering conditions.

[0009] In another aspect, embodiments of the present disclosure relate to a method of manufacturing a polycrystalline diamond construction that includes shaping a first mixture of a precursor diamond material and a binder into a first region shape, coating a portion of the first region shape with a powdered material selected from at least one of a powdered non-refractory metal and ceramic, and sintering the first mixture and the powdered material to form the polycrystalline diamond construction.

[0010] In yet another aspect, embodiments of the present disclosure relate to a polycrystalline diamond composite construction that includes a first region made of polycrystalline diamond, the polycrystalline diamond having a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the bonded diamond crystals; and a plurality of second regions extending radially within the first region, the plurality of second regions made of a non-refractory metal. [0011] Other aspects and advantages of the claimed subject matter will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

[0012] Embodiments of the present disclosure are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components.

[0013] FIG. 1 shows the microstructure of conventionally formed polycrystalline diamond.

[0014] FIG. 2 is a cross-sectional view of a polycrystalline diamond composite construction being assembled according to embodiments of the present disclosure.

[0015] FIG. 3 is a cross-sectional view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0016] FIG. 4 is an image of a cross-section view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0017] FIG. 5 is a cross-sectional view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0018] FIG. 6 is a cross-sectional view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0019] FIG. 7 is a cross-sectional view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0020] FIG. 8 is a cross-sectional view of a polycrystalline diamond composite construction according to embodiments of the present disclosure.

[0021] FIG. 9 shows a downhole cutting tool having cutting elements made of a polycrystalline diamond composite construction according to embodiments of the present disclosure. [0022] FIG. 10 shows a downhole cutting tool having cutting elements made of a polycrystalhne diamond composite construction according to embodiments of the present disclosure.

DETAILED DESCRIPTION

[0023] Embodiments of the present disclosure relate generally to polycrystalline diamond composite constructions and methods for manufacturing polycrystalline diamond composite constructions. According to some embodiments, a method of manufacturing a polycrystalline diamond construction may include sintering together multiple regions of different material, where at least one of the multiple regions is made of polycrystalline diamond and at least one other region is made of a material that does not include diamond. In some embodiments, multiple polycrystalline diamond regions may be formed, where different polycrystalline diamond regions have at least one property difference there between.

[0024] As used herein, the term "polycrystalline diamond" or "PCD" is used to refer to polycrystalline diamond that has been formed, at high pressure/high temperature (HPHT) conditions, through the use of a metal solvent catalyst, such as those metals included in Group VIII of the Periodic table, that remains within the material microstructure. Precursor material used to form polycrystalline diamond may include synthetic or natural diamond powder. Synthetic diamond powder may include small amounts of solvent metal catalyst material and other materials entrained within the diamond crystals themselves. The diamond powder, whether synthetic or natural, may be combined with a desired amount of solvent catalyst to facilitate desired intercrystalline diamond bonding during HPHT processing, or solvent catalyst may be infiltrated into the diamond powder from a catalyst source. Polycrystalline diamond regions having at least one property difference there between may be formed, for example, using varying ratios of precursor materials, differently sized diamond particles, and/or different types of catalyst.

[0025] According to embodiments of the present disclosure, a polycrystalline diamond composite construction may be made by shaping a first mixture of a precursor diamond material and a binder into a first region shape. A portion of the first region shape may be coated with a powdered material that does not include diamond. According to some embodiments, the powdered material may be selected from at least one of a powdered non- refractory metal and a ceramic material. In some embodiments, a portion of the first region shape may be coated with an inert metal having a melting temperature greater than 1600°C. The powdered material coated onto at least a portion of the first region may be selected depending on the end use of the manufactured polycrystalline diamond composite construction. For example, polycrystalline diamond composite constructions used as cutting elements in some downhole drilling operations may have one or more non-PCD regions made from metal carbide or refractory metal powdered material disposed between two or more PCD regions made from diamond precursor material. Additional mixtures of precursor diamond material and/or additional coatings of diamond free powdered material may be positioned around the first region shape. The first mixture and the powdered material (and any additional diamond mixtures and coating material) may then be sintered to form the polycrystalline diamond composite construction.

[0026] In one aspect, the use of one or more inert metal layers or shapes within the PCD composite construction enhances the toughness of the material. In another aspect, use of a powdered material to form the diamond free layer or shape enables shape flexibility for the composite construction. Precursor diamond material combined with an organic binder can easily be formed a wide variety of shapes by methods such as a roll-forming, extrusion, stamping or coining or casting. The powdered metal, metal carbide, refractory metal or ceramic forming the diamond free layer may be coated onto the diamond in one or more coating processes to create a composite construction having the desired shape. In yet another aspect, the powdered diamond free material may permit infiltration by the solvent catalyst used to sinter the diamond through the diamond free layer, so that less time is required for a sintering reaction to take place.

[0027] FIGS. 2 and 3 show a diagram of a method for forming a polycrystalline diamond composite construction according to embodiments of the present disclosure. As shown in FIG. 2, a first mixture of a precursor diamond material and a binder is shaped into a first region shape 210. The binder may include, for example, an organic binder or other suitable binder that may help hold the shape of the first region. The first region shape 210 may be formed, for example, by rolling, tape casting, extruding, stamping, coining or using a mold or displacement, e.g., placing the first mixture on a complementary shaped mold or displacement.

[0028] Precursor diamond material may include, for example, diamond powders having an average diameter particle size in the range of from submicrometer in size to 0.1 mm, for example, in the range of from about 0.001 mm to 0.08 mm. The diamond powder may contain particles having a mono or multi-modal size distribution. For example, the diamond powder may comprise a multimodal distribution of diamond particles having about 80 percent by volume diamond particles sized relatively larger and 20 percent by volume diamond particles sized relatively smaller, a 70/30 ratio of two differently sized diamond particles, a 60/40 ratio of two differently sized diamond particles, or a 50/50 ratio of two differently sized diamond particles. In other embodiments, a multimodal distribution may include three or more diamond particle types having different ranges of average diamond particle sizes. In an embodiment for a particular application, the diamond powder may have an average particle size of from about 5 to 30 micrometers. However, it is to be understood that the diamond particles having a particle size greater than this amount, e.g., greater than about 30 micrometers, may be used for certain drilling and/or cutting applications. In regions formed of diamond powder having a multimodal distribution, the differently sized diamond particles are mixed together by conventional process, such as by ball or attrittor milling for as much time as necessary to ensure good uniform distribution. Further, different diamond regions (formed of a mixture of diamond precursor material and a binder) may have different average diamond particle sizes and/or distributions of diamond particles (either mono- or multi-modal size distributions), or different diamond regions may be formed using diamond precursor material having the same average diamond particle size and/or the same distribution of diamond particles.

[0029] Suitable organic binders may be or include one or more waxes, resins or other organic compounds that are insoluble, or at least substantially insoluble, in water. Waxes may include, for example, animal waxes, vegetable waxes, mineral waxes, synthetic waxes, or any combination thereof. Illustrative animal waxes may include, but are not limited to, bees wax, spermaceti, lanolin, shellac wax, or any combination thereof. Illustrative vegetable waxes may include, but are not limited to, carnauba, candelilla, or any combination thereof. Illustrative mineral waxes may include, but are not limited to, ceresin and petroleum waxes (e.g. , paraffin wax). Illustrative synthetic waxes may include, but are not limited to, polyolefins (e.g., polyethylene), polyol ether-esters, chlorinated naphthalenes, hydrocarbon waxes, or any combination thereof. The organic binder may also include other organic compounds that are soluble or insoluble in organic solvents. Illustrative compounds that may include, but are not limited to, polyglycol, polyethylene glycol, hydroxyethylcellulose, tapioca starch, carboxymethylcellulose, polypropylene carbonate, or any combination thereof. Illustrative organic binders may also include, but are not limited to, starches, and cellulose, or any combination thereof. The organic binders may also include, but are not limited to, microwaxes or microcrystalline waxes. Microwaxes may include waxes produced by de-oiling petrolatum, which may contain a higher percentage of isoparaffinic and naphthenic hydrocarbons as compared to paraffin waxes. Resins may include materials derived from plants containing terpenes, resin acids, gums and other compounds including plant oils, saps or mucilage. Synthetic compounds with similar chemistry to naturally derived materials may also be used. Other suitable binders may include, for example, acrylic copolymers, arabic gum, and the like. 30] Referring still to FIGS. 2 and 3, a portion of the first region shape 210 may be coated with a material other than diamond, which may be applied dry or combined with a second binder, to form a diamond free second region 220. According to some embodiments, the second region 220 may be made of a powdered material selected from at least one of a powdered non-refractory metal and a ceramic material. For example, the powdered material may include alumina (AI2O3), zirconia (ZrC ), silicon nitride (S13N4), silicon carbide (SiC), or other non-refractory ceramics or metal carbides. In some embodiments, the powdered material may be an inert metal having a melting temperature greater than 1600°C, such as rhodium, ruthenium, osmium, iridium, platinum and alloys thereof. In some embodiments, the powdered material may be selected from one or more Group VIII metals of the Periodic Table other than cobalt, nickel or iron. For example, the powdered material may be selected from one or more Group VIII metals having a melting temperature greater than about 1550°C. Further, in some embodiments, a second binder may be combined with the powdered material to form a coating mixture, which may be disposed on a portion of the first region shape. The second binder may be the same as or different than the binder used in the first mixture. [0031] The diamond free second region 220 may be applied to a portion of the first region shape 210, for example, by spray coating, dusting, dipping or casting. In some embodiments, multiple coating processes or an additive manufacturing process may be used to build up a desired thickness of the second region 220. Further, in some embodiments, multiple coating processes or an additive manufacturing process may be used to vary the composition of the second region, for example, by varying the ratios of two or more materials forming the second region.

[0032] In the embodiment shown in FIGS. 2 and 3, an additional mixture of an additional precursor diamond material and an additional binder may be provided over the first region shape 210 and the diamond free second region 220. According to some embodiments, the steps of providing a mixture of precursor diamond material and binder and coating at least a portion of the diamond mixture may be repeated more than twice, more than five times, more than 20 times, more than 50 times or more than 75 times, depending on, for example, the size of the different regions formed within the polycrystalline diamond composite construction and the total size and application of the manufactured polycrystalline diamond composite construction final use. At least one additional diamond mixture may have a composition different than the first diamond mixture and/or at least one additional diamond mixture may have the same composition as the first diamond mixture.

[0033] In an embodiment, the additional mixture 230 is placed adjacent the diamond free second region 220, such that the additional mixture 230 interfaces with the second region 220 and a portion of the first region 210. Particularly, as shown, the additional mixture 230 interfaces with the portion 215 of the first region 210 along its outer periphery 214. The interfacing diamond mixtures portion 215 may extend around the entire periphery 214 of the additional mixture 230 and the first region 210. In other embodiments, the interfacing diamond mixtures portion 215 may extend partially around the periphery 214 of the additional mixture 230 and the first region 210. Further, the interfacing diamond mixtures portion 215 may extend a depth from the outer periphery 214 ranging, for example, from a lower limit selected from 1/10, 1/8, ¼, or 1/3 to an upper limit selected from 1/8, ¼, 1/3 or ½ of the distance from the outer periphery 214 to the centerline 205 of the assembled construction, where any lower limit may be used in combination with any upper limit. In some embodiments, the interfacing diamond mixtures portion 215 may extend a depth from the outer periphery 214 ranging, for example, from a lower limit selected from 0.2 mm, 0.5 mm, 1 mm, or 2 mm to an upper limit selected from 0.5 mm, 1 mm, 2 mm or 4 mm, where any lower limit may be used in combination with any upper limit.

[0034] Further, the additional mixture may be shaped to have the same shape as the first region shape or a different shape than the first region shape. In some embodiments, at least one additional mixture of precursor diamond material may be shaped to have an outer periphery correspond with an outer periphery of the first region. For example, as shown in FIG. 2, the additional mixture 230 is shaped to have a width 232 measured between the additional mixture outer periphery 234 that is the same as a width 212 measured between the first region outer periphery 214. The outer periphery 214 of the first region corresponds with the outer periphery 234 of the additional mixture such that upon forming the polycrystalline diamond composite construction, the polycrystalline diamond composite construction has a continuous or smooth outer side surface. In some embodiments, the outer periphery of two or more adjacent regions may have different sizes or shapes, such that upon forming the polycrystalline diamond composite construction, the polycrystalline diamond composite construction has a discontinuous or disjointed outer side surface.

[0035] As shown in FIG. 3, the different regions may be assembled together and sintered to form the polycrystalline diamond composite construction 200. According to some embodiments, binder material used in shaping and assembling a polycrystalline diamond composite construction may be removed prior to sintering. For example, in the embodiment shown in FIGS. 2 and 3, the binder material in the first mixture 210, any second binder material used in the second region 220, and the additional binder in the additional mixture 230 may be removed prior to sintering, for example, by heating the assembly or using a chemical decomposition removal process.

[0036] Sintering processes used to form a polycrystalline diamond composite construction according to embodiments of the present disclosure may include subjecting the precursor materials of the polycrystalline diamond composite construction to high pressure and high temperature conditions in the presence of a catalyst, such as cobalt, nickel, iron and combinations thereof. The catalyst may be provided by mixing the catalyst material with diamond precursor material prior to sintering or by providing a catalyst source adjacent to at least one region of diamond precursor material. A catalyst source may include, for example, a catalyst metal in the form of a disc or solid body, or a substrate, such as a cemented metal carbide substrate having a solvent metal catalyst as a cementing agent. During the sintering process, catalyst material from a catalyst source may be melted and sweep (advance or diffuse) through the precursor material for use in diamond recrystallization or crystal intergrowth to form the polycrystalline diamond regions. By using a powdered material to form the non-PCD regions disposed between two or more polycrystalline diamond regions, catalyst may more easily sweep through the diamond free regions to adjacent diamond regions. In other words, by providing the coating in powder form, the coating may not act as a barrier to infiltration by the solvent catalyst used to sinter the diamond regions.

[0037] According to some embodiments, a sintering process may include placing assembled precursor materials of a polycrystalline diamond composite construction in a container. The container may be made of, for example, a refractory metal such as molybdenum, tantalum, titanium, tungsten and zirconium. The container and its contents may be placed within a reaction cell of a high pressure high temperature ("HPHT") apparatus and subjected to processing conditions having sufficiently high pressure and high temperature to both sinter the precursor material of adjacent regions together and to cause intercrystalline bonding between precursor diamond particles in the diamond regions forming polycrystalline diamond. Sintering processes may include, for example, pressures of at least about 45-55 kilobars and temperatures of at least about 1300-1400°C. The minimum sufficient temperature and pressure in a given embodiment may depend on other parameters such as the presence of a catalytic material, such as cobalt, and the density of the precursor material.

[0038] According to some embodiments of the present disclosure, a method of manufacturing a polycrystalline diamond construction may include placing diamond powder (to form a polycrystalline diamond region upon sintering) in a reaction container and placing a layer of a ceramic material powder or an inert metal having a melting temperature greater than 1600°C (to form a non-PCD region upon sintering) in powdered form on top of the diamond powder in the reaction container, where the layer of the ceramic material or inert metal extends across the entire inner diameter of the reaction container. In such embodiments, the layer of the ceramic material or inert metal extending across the entire inner diameter of the reaction container may form a non-PCD region extending to and thereby forming part of the outer periphery of the sintered polycrystalline diamond composite construction. Further, additional diamond powder (to form an additional PCD region upon sintering) may be placed on top of the layer of ceramic material or inert metal in the reaction container.

[0039] In some embodiments, a substrate material and metallic binder (to form a substrate upon sintering) may also be placed into the reaction container, on top of the additional diamond powder. The steps of placing a layer of ceramic material or inert metal (to form a non-PCD/diamond free region) and placing of additional diamond powder (to form additional PCD regions) in the reaction container may be repeated before placing the substrate in the reaction container. Upon assembling the precursor materials into the reaction container, the reaction container and its contents may be subjected to high temperature, high pressure sintering conditions to form the polycrystalline diamond composite construction.

[0040] According to some embodiments of the present disclosure, a method of manufacturing a polycrystalline diamond construction may include forming an assembly of the polycrystalline diamond construction precursor materials. Assembling includes placing diamond powder in a reaction container, placing a layer of an inert metal having a melting temperature greater than 1600°C on top of the diamond powder in the reaction container, and placing additional diamond powder on top of the layer of inert metal in the reaction container. In some embodiments, the layer of inert metal may be placed on top of a portion of the diamond powder, such that the diamond powder also interfaces with the additional diamond powder. In such embodiments, the layer of inert metal does not extend to an outer periphery of the assembly. In another embodiment, the layer of inert metal may extend around the complete outer periphery of the assembly. In yet another embodiment, the layer of inert metal may extend around at least part of the outer periphery of the assembly. [0041] A substrate material and a metallic binder may be placed into the reaction container adjacent to the assembly, on top of the additional diamond powder. According to some embodiments, the steps of placing a layer of inert metal over at least a portion of a diamond powder region and placing additional diamond powder in the reaction container may be repeated before placing a substrate in the reaction container. The reaction container and its contents (the assembly and substrate) may then be subjected to high temperature, high pressure sintering conditions to form the polycrystalline diamond construction.

[0042] FIG. 4 shows an image of a composite construction assembly 400 in its green-state (before it is sintered), where the composite construction is broken to show a cross section of its multiple regions. The assembly 400 has a first mixture of a precursor diamond powder and an organic binder that was shaped into a first region 412. A second region 422 of diamond free material (to form a non-PCD region) was placed over a portion of a top surface of the first region 412, such that the second region 422 does not extend to the outer periphery 414 of the assembly 400. Additional diamond mixtures 410 (precursor diamond powder and an organic binder) and diamond free material were alternately layered, where at least one region 420 of diamond free material extends across an entire radial dimension of the assembly 400, and thereby forms part of the outer periphery 414.

[0043] The assembly 400 has a non-cylindrical shape, including a depression 442 formed along the assembly base surface 440. Other embodiments may have other non-planar base surfaces, for example, one or more depressions and/or one or more protrusions formed in the base surface, or may have other non-cylindrical shapes, for example, including a non- planar base surface and upper surface, a non-circular outer periphery, or a combination of a non-planar base and/or upper surface and a non-circular outer periphery. In the embodiment shown, multiple diamond mixture regions 410, 412 form portions of the non- planar base surface 440. In other words, multiple regions 410, 412 of diamond mixtures (precursor diamond powder and an organic binder) extend across a radial dimension of the assembly measured from the outer periphery 414 to the depression 442. In other embodiments, a first region formed of a diamond mixture of precursor diamond powder and organic binder may be placed along and thus form an entire non-planar base surface of an assembly. In some embodiments, a non-cylindrical assembly may be formed by placing regions of diamond material and regions of diamond free material in a mold or container having the negative shape of the non-cylindrical assembly to be formed. In some embodiments, a non-cylindrical assembly of a diamond composite construction may be formed by placing regions of diamond material and regions of diamond free material in a container over a substrate having a non-planar interface surface. For example, a substrate may have a protrusion formed in its interface surface, where a plurality of diamond mixtures and diamond free material mixtures are alternately layered over the interface surface.

[0044] Referring now to FIGS. 5 and 6, images of two embodiments of polycrystalline diamond composite constructions 500, 600 are shown along a cross-sectional profile, where the polycrystalline diamond composite constructions 500, 600 have a non-planar base surface 540, 640 interfacing a substrate 550, 650 at a corresponding non-planar interface surface 555, 655. FIG. 5 shows a polycrystalline diamond composite construction 500 having a plurality of PCD regions 510 alternating with a plurality of non- PCD/diamond free regions 520, where at least one PCD region 510 and at least one non- PCD region 520 intersects with, and thus forms part of, the base surface 540. FIG. 6 shows a polycrystalline diamond composite construction 600 having a plurality of PCD regions 610 alternating with a plurality of non-PCD/diamond free regions 620, where a first PCD region 612 extends along, and thus forms, the entire base surface 640.

[0045] Polycrystalline diamond composite constructions 500, 600 may be formed by placing a substrate 550, 650 in a container 530, 630, the substrate 550, 650 having a non- planar interface surface 555, 655. A first diamond mixture of precursor diamond powder and an organic binder is placed over at least a portion of the interface surface 555, 655, which will form a first PCD region 512, 612 upon sintering. A second region made of material other than diamond (which will form a non-PCD/diamond free region 520, 620 upon sintering) is placed over at least a portion of the first diamond mixture. Additional diamond mixtures and diamond free material are alternately layered within the container 530, 630 to build a total height of the assembly 500, 600. The assembly may then be sintered in the presence of a catalyst under high pressure and high temperature conditions sufficient to cause diamond re -crystallization or crystal intergrowth in the diamond mixture regions to form the PCD regions. The catalyst may be provided from the substrate or from a catalyst source positioned adjacent one or more diamond mixtures. As shown in FIGS. 5 and 6, the container 530, 630 may become sintered to the polycrystalline diamond composite construction 500, 600 upon subjecting the assembly to high pressure, high temperature conditions. The attached container 530, 630 may be subsequently removed, for example, by machining away the container material.

[0046] According to embodiments of the present disclosure, a polycrystalline diamond composite construction may include a first region of polycrystalline diamond and a plurality of second regions extending radially within the first region. The polycrystalline diamond is made of a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the bonded diamond crystals. In some embodiments, the plurality of second regions may be made of a non-refractory metal, for example, a non-refractory metal having a melting temperature greater than 1600°C or a Group VIII metal other than cobalt, nickel or iron.

[0047] For example, FIG. 7 shows a cross-sectional view of a polycrystalline diamond construction 700 according to embodiments of the present disclosure, where the polycrystalline diamond composite construction has a first region 710 made of polycrystalline diamond and a plurality of second regions 720 made of non- polycrystalline diamond/diamond free material extending radially within the first region 710. The polycrystalline diamond first region 710 is made of a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the bonded diamond crystals. The plurality of second regions 720 are made of one or more materials not including diamond, such as described above. The interstitial regions disposed among the bonded diamond crystals of the polycrystalline diamond first region 710 are distinct from the plurality of second regions 720, the interstitial regions forming part of the polycrystalline diamond microstructure, while the second regions 720 extend through the polycrystalline diamond microstructure on a macroscopic scale.

[0048] As shown, the polycrystalline diamond composite construction 700 has a non- planar upper surface 702, which includes a rounded apex 704, an outer periphery 706 extending around the non-planar upper surface 702, and a base surface 708 interfacing with an interface surface of a substrate 750. In other embodiments, a non-planar upper surface may have other shapes. For example, a non-planar upper surface may have a cross- sectional diameter that decreases for at least a portion of the extension of the polycrystalline diamond composite body, such that the non-planar upper surface forms a truncated cone shape. In other examples, a non-planar upper surface may form a chisel shape, an elongated peak (a peak extending partially across the diameter of the composite body), or have one or more peaks or protrusions that are not centrally located, for example, one or more peaks formed at or adjacent to the outer periphery. The outer periphery 706 of the construction may extend circumferentially around the upper surface 702, defining a diameter of the construction, or an outer periphery of a construction may have a non- circular cross sectional shape, defining one or more radial dimensions. For example, an outer periphery of a construction having an elliptical cross-sectional shape may define a major axis radial dimension and a minor axis radial dimension smaller than the major axis radial dimension.

[0049] The plurality of second regions 720 extend less than the entire radial dimension of the first region 710, and each of the non-planar upper surface 702, outer periphery 706 and base surface 708 are formed entirely of the polycrystalline diamond first region 710, according to an embodiment. In other words, the polycrystalline diamond first region 710 continuously extends along each of the upper surface 702, the outer periphery 706 and the base surface 708, where the second regions 720 do not intersect with or form a portion of the upper surface 702, the outer periphery 706 or the base surface 708. According to embodiments of the present disclosure, at least one outer surface of a polycrystalline diamond composite construction may be formed entirely of polycrystalline diamond, for example, one or more of an upper surface, an outer periphery and/or a base surface.

[0050] According to other embodiments of the present disclosure, at least one second region may intersect with a portion of an outer surface of a polycrystalline diamond composite construction, such that the portion of the outer surface is formed of the second region material. For example, at least one second region may extend across the entire diameter of a polycrystalline diamond composite construction, through a first region formed of polycrystalline diamond, and intersecting a portion of at least one outer surface, such that the outer surface is formed of both the diamond free second region material and polycrystalline diamond. [0051] Further, a polycrystalline diamond composite construction may have a first region made of at least one polycrystalline diamond material and a plurality of second regions made of a material other than diamond disposed intermittently through the first region. According to some embodiments, a first region may include at least two polycrystalline diamond materials, where a first polycrystalline diamond material has at least one property difference from a second polycrystalline diamond material.

[0052] For example, FIG. 8 shows a cross-sectional view of a polycrystalline diamond composite construction 800 according to embodiments of the present disclosure, where the polycrystalline diamond composite construction has a first region 810 made of at least one polycrystalline diamond material and a plurality of second regions 820 made of non- polycrystalline diamond material disposed intermittently within the first region 810. The first region 810 is made of a first polycrystalline diamond material 812 and a second polycrystalline diamond material 814, where the first polycrystalline diamond material 812 and the second polycrystalline diamond material 814 have at least one property difference there between, e.g., different average grain sizes, different amounts or types of catalyst remaining within the interstitial regions of the polycrystalline diamond, different thermal stability. For example, the first polycrystalline diamond material may have a lesser amount of catalyst material than the second polycrystalline diamond material within the polycrystalline diamond interstitial regions.

[0053] The polycrystalline diamond composite construction 800 has an upper surface 802, an outer periphery 806 encompassing the upper surface, and a base surface 808 opposite the upper surface 802. The plurality of second regions 820 extend partially across a radial dimension such that the second regions 820 do not intersect with the upper surface 802, the outer periphery 806, or the base surface 808. The first region 810 extends continuously along each of the outer surfaces, and thus each of the outer surfaces is formed of polycrystalline diamond. In the embodiment shown, the upper surface is formed of the first polycrystalline diamond material 812, the base surface 808 is formed of the second polycrystalline diamond material 814, and the outer periphery 806 is formed of the first and second polycrystalline diamond materials 812, 814. [0054] Composite constructions made according to embodiments of the present disclosure may be used to form cutting elements or other cutting structures in downhole cutting tools, such as drill bits, reamers, and mills. For example, as shown in FIG. 9, a roller cone bit 30 includes a bit body 32 having a threaded connection at one end 34 and one or more legs extending from the opposite end. A roller cone 36 is mounted on each leg and is able to rotate with respect to the bit body 32. On each cone 36 of the drill bit 30 are a plurality of cutting elements 38, arranged in rows about the surface of the cone 36 to contact and cut through formation encountered by the drill bit. Roller cone bits 30 are designed such that as a drill bit rotates, the cones 36 of the roller cone bit 30 roll on the bottom surface of the well bore (called the "bottomhole") and the cutting elements 38 scrape and crush the formation beneath them. The cutting elements 38 on the roller cone bit 30 include polycrystalhne diamond composite constructions according to embodiments of the present disclosure, where one or more second regions made of a material other than diamond are disposed within one or more first regions made of polycrystalline diamond. At least one of the cutting elements 38 has a non-planar cutting surface 39 formed entirely of a polycrystalline diamond first region. A substrate is attached to the polycrystalline diamond composite, and the substrate is attached to the roller cone 36, thereby attaching the cutting element 38 to the bit 30.

[0055] FIG. 10 shows an example of a fixed cutter bit 100 having a plurality of cutting elements 150 made of polycrystalline diamond composite material according to embodiments of the present disclosure. The drill bit 100 includes a bit body 110 having a threaded pin end 111 and a cutter end 115. The cutter end 115 includes a plurality of ribs or blades 120 arranged about the rotational axis L of the drill bit and extending radially outward from the bit body 110. Cutting elements 150 are embedded in the blades 120 at predetermined angular orientations and radial locations relative to a working surface and with a desired back rake angle against a formation to be drilled. The cutting elements 150 include a polycrystalline diamond composite material according to embodiments of the present disclosure disposed on a substrate, where the polycrystalline diamond composite contacts and cuts the formation and the substrate is attached to the blade.

[0056] Other cutting elements or downhole cutting structures may be made of polycrystalline diamond composite constructions according to embodiments of the present disclosure. For example, a polycrystalline diamond composite material of the present disclosure may include one or more first regions made of polycrystalline diamond and one or more second regions made of a material other than diamond formed within the first region. A first region may extend continuously along a cutting surface and at least a portion of an outer periphery surface of a cutting element or other downhole cutting structure (where the one or more second regions do not intersect with the cutting surface or the portion of the outer periphery), such that the cutting surface and the portion of the outer periphery surface is formed entirely of polycrystalline diamond. 57] Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. It is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words 'means for' together with an associated function.

Claims

CLAIMS What is claimed is:

1. A method of manufacturing a polycrystalline diamond construction, comprising:

placing diamond powder in a reaction container;

placing a diamond free layer on top of the diamond powder in the reaction container, the diamond free layer comprising a ceramic material powder or an inert metal having a melting temperature greater than 1600°C in powdered form and extending across the entire inner diameter of the reaction container; placing additional diamond powder on top of the diamond free layer in the reaction container;

placing a substrate material into the reaction container on top of the additional diamond powder; and

subjecting the reaction container and its contents to high temperature, high pressure sintering conditions.

2. The method of claim 1, further comprising:

repeating the placing the diamond free layer and the placing of additional diamond powder in the reaction container before placing the substrate in the reaction container.

3. A method of manufacturing a polycrystalline diamond construction, comprising:

placing diamond powder in a reaction container;

placing a layer of an inert metal having a melting temperature greater than 1600°C in powdered form on top of the diamond powder in the reaction container;

placing additional diamond powder on top of the layer of inert metal in the reaction container;

4. The method of claim 3, further comprising: repeating the placing the layer of inert metal and the placing of additional diamond powder in the reaction container before placing the substrate in the reaction container

5. The method of claim 3, wherein the additional diamond powder interfaces with both the layer of inert material and a portion of the diamond powder.

6. A method of manufacturing a polycrystalline diamond construction, comprising:

shaping a first mixture of a precursor diamond material and a binder into a first region shape;

coating a portion of the first region shape with a powdered material selected from at least one of a powdered non-refractory metal and a powdered ceramic material;

sintering the first mixture and the powdered material to form the polycrystalline diamond construction.

7. The method of claim 6, further comprising providing at least one additional mixture of an additional precursor diamond material and an additional binder.

8. The method of claim 7, wherein the at least one additional mixture has a composition different than the first mixture.

9. The method of claim 7, wherein the at least one additional mixture has the same

composition as the first mixture.

10. The method of claim 7, further comprising:

placing the at least one additional mixture adjacent the powdered material, such that the additional mixture interfaces with the powdered material and at least a second portion of the first mixture.

11. The method of claim 6, further comprising removing the binder prior to sintering.

12. The method of claim 6, wherein coating comprises combining a coating binder with the powdered material to form a coating mixture and disposing the coating mixture on the portion of the first region shape.

13. A polycrystalline diamond composite construction comprising: a first region comprising polycrystalline diamond, the polycrystalline diamond comprising a plurality of bonded diamond crystals and a plurality of interstitial regions disposed among the bonded diamond crystals; and

a plurality of second regions extending radially within the first region, the plurality of second regions comprising a non-refractory metal.

14. The construction of claim 13, wherein the non-refractory metal has a melting temperature greater than 1600°C.

15. The construction of claim 14, wherein the non-refractory metal comprises a Group VIII metal.

16. The construction of claim 13, wherein the plurality of second regions extends across the entire diameter of the first region.

17. The construction of claim 13, further comprising at least one outer surface, the at least one outer surface formed entirely of the first region.

18. The construction of claim 13, further comprising a substrate bonded to an end of the first region.

19. The construction of claim 13, wherein the first region further comprises a second

polycrystalline diamond material having at least one property difference from the polycrystalline diamond.

20. A drill bit comprising a bit body and at least one construction of claim 13 disposed on the bit body.