CN104769208A - Ultra-hard constructions with improved attachment strength - Google Patents

Abstract

Ultra-hard constructions (40) comprise a sintered diamond-bonded body (42) having a matrix of bonded-together diamond grains and a plurality of interstitial regions substantially free of a catalyst material. A metal material (56) comprising a carbide constituent is disposed on a substrate interface surface (54) of the diamond body (42). A substrate (44) is attached to the diamond-bonded body (42) through a braze joint (46). The braze joint (46) is formed from a non-active braze material that reacts with the substrate and metal material. The braze joint is formed at the melting temperature of the non-active braze material in the absence of high-pressure conditions. In an example embodiment, the non-active braze material reacts with the carbide constituent in the metal material. Example materials useful for forming the non-active braze material include those selected from Cu, Ni, Mn, Au, Pd, and combinations and alloys thereof.

Description

Super hard structure with improved attachment strength

Background technique

The use of structures comprising superhard and metallic components bonded together is known in the art. An example of such a structure can be found in the form of a cutting element comprising a superhard component bonded to a metal component. In an embodiment of such a cutting element, the wearing or cutting portion is formed by said superhard component and the metal portion of said cutting element is attached to the wearing and/or cutting means. In this known structure, superhard components may be made of polycrystalline materials such as polycrystalline diamond (PCD), polycrystalline cubic boron nitride (PcBN), etc., which have a higher degree of abrasion resistance.

In particular examples, the superhard component may be treated to render it substantially free of catalyst material (e.g., a metal selected from Group VIII of the Periodic Table) for forming/sintering PCD under high pressure/high temperature conditions PCD, and includes diamond crystals bonded together. PCD treated to be substantially free of the catalyst material is referred to as thermally stable polycrystalline diamond (TSP) because it has been found that removal of the catalyst material eliminates possible damage to the diamond as the temperature increases. The thermal stability of the resulting diamond body is improved by undesired degradation and thermal expansion mismatch that adversely affect the useful life of the body.

While TSPs provide the desired improvement in thermal stability, a well-known problem with existing TSPs is the lack of catalyst material within their bodies, preventing subsequent attachment of the TSP body to the metal substrate by solvent catalyst infiltration. Furthermore, such TSP bodies have a coefficient of thermal expansion that is significantly different from conventional matrix materials (such as cermets like WC—Co, etc.) that are typically infiltrated or otherwise attached to PCD bodies. Attaching these substrates to the TSP body is highly desirable in order to provide a TSP compact that can be easily adapted for use in many desired applications. However, due to the different thermal expansion properties between the TSP body and the substrate, and the poor wettability of the TSP body due to the substantial absence of catalyst materials, it is difficult to bond the TSP body to the conventionally used substrate. Accordingly, some TSP bodies are directly attached or mounted to the desired end-use equipment without the presence of a mating substrate.

It is well known that the TSP body can be attached to the desired metal substrate by using known active brazing materials having relatively low melting points and low yield strengths. Combining the known limitations of active brazing materials with the inherent poor wettability of the TSP body, it follows that the brazed bond formed between the TSP body and the substrate is not as good as that formed by infiltration in conventional PCD and metal substrates. The connection between them is strong. Due to the lower yield strength of the brazing material, the resulting structure has a reduced service life, which will lead to delamination of the TSP body and matrix during operation.

Contents of the invention

The superhard structures described herein comprise a diamond bonded body comprising a matrix phase of bonded diamond grains and a plurality of interstitial regions interposed between the bonded diamond grains. The interstitial region is substantially free of catalyst material for sintering the diamond bonded body under high pressure/high temperature conditions. Metal material is disposed on the matrix interface surface of the diamond body. In an exemplary embodiment, the metallic material has a carbide composition. In an exemplary embodiment, the layer thickness of the metallic material is in the range of about 0.1 to 10 microns. The structure further includes a matrix coupled to the diamond bonded body. The matrix may include a carbide component. The base body is attached to the diamond bonded body by a brazed joint interposed between the metallic material and the base body. The braze joint is formed from a non-reactive braze material that reacts with the substrate and metallic material. In one exemplary embodiment, the brazed joint is formed at the melting point of the non-reactive brazing material without high pressure. Such superhard structured diamond bonded bodies are produced under high pressure/high temperature conditions. The substrate interface surface of the body thus formed is treated to include said metallic material layer thereon. A metal matrix is attached to the diamond bonded body by a braze joint comprising the non-reactive brazing material at about the melting point of the brazing material and in the absence of high pressure. A carburizing treatment may be performed before attaching the base body, if desired. 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.

Description of drawings

An embodiment of a superhard structure is described with reference to the following figures:

Figure 1 is a view of a portion of a diamond bonded body that has been processed to remove catalyst material used to form the diamond bonded body;

Figure 2 is a perspective view of a diamond bonded body which has been processed to remove catalyst material used to form the diamond bonded body;

Figure 3 is a cross-sectional side view of a diamond bonded body including metallic material disposed on the body-matrix interface surface;

4 is a cross-sectional side view of a superhard structure as described herein, comprising a diamond-bonded body of metallic material disposed on a body-matrix interface surface, and further comprising a brazed joint interposed therebetween and bonding the matrix to brazing material of the body;

Figure 5 is a side view of a superhard structure implemented in the form of an insert as described herein;

6 is a side perspective view of a rotary cone drill bit including a plurality of inserts shown in FIG. 5;

7 is a side perspective view of an impact or percussion drill bit including a plurality of inserts shown in FIG. 5;

Figure 8 is a perspective view of a superhard structure implemented as a shear cutter as described herein; and

9 is a side perspective view of a drag bit including the plurality of shear cutters shown in FIG. 8 .

Detailed ways

The superhard and metallic structures disclosed herein comprise a thermally stable polycrystalline diamond (TSP) bonded body that is substantially free of the catalyst material originally used to sinter the body and is specifically designed to be bonded by brazing. Attachment to a substrate or end-use device in a manner that provides enhanced attachment strength over conventional TSP structures.

As used herein, the term "superhard" is understood to refer to those materials known in the art to have a grain hardness of about 4000 HV or greater. Such superhard materials may include those composed of consolidated materials capable of exhibiting physical stability at temperatures above about 750°C, and for some applications above about 1000°C. Such superhard materials may include, but are not limited to, diamond, cubic boron nitride (cBN), diamond-like carbon, boron suboxide, aluminum manganese borides, and those exhibiting similarities in the boron-nitrogen-carbon phase diagram to cBN and other Ceramic materials have hardness values for other materials.

Once polycrystalline diamond (PCD) has been treated to remove the catalyst material (such as the Group VIII species described above) originally used to sinter or form the PCD under high pressure/high temperature (HPHT) conditions, it is Useful materials for forming the superhard components. As used herein, the term "catalyst material" refers to a material originally used to promote diamond-diamond bonding or sintering for forming said PCD under HPHT processing conditions.

TSP has a material microstructure characterized by a polycrystalline matrix phase comprising diamond grains or crystals bonded together and a plurality of voids or voids present within the matrix in interstitial regions arranged Between the bonded diamond grains. The TSP material is initially formed by bonding adjacent diamond grains or crystals together under HPHT treatment conditions. The use of a suitable catalyst material (such as a metal solvent catalyst selected from Group VIII of the Periodic Table of the Elements) promotes the bonding of the diamond grains together under HPHT conditions, thereby forming a conventional PCD, which includes being disposed in the plurality of voids or catalyst material in the pores.

Diamond grains that can be used to form the TSP component or body may include natural and/or synthetic diamond powder having an average particle size ranging from submicron sizes to 100 microns, for example in the range of about 1 to 80 microns. The diamond powder may contain grains with a mono- or multi-modal size distribution. In an exemplary embodiment, the average particle size of the diamond powder is about 20 microns. Where the diamond powder used has grains of different sizes, the diamond grains are mixed together by conventional processes, for example by ball mills or attritors, for a sufficient time to ensure a good homogeneous distribution.

Clean diamond grain powder to improve sinterability of powder by treatment at high temperature, vacuum or reduced pressure. The diamond powder mixture is loaded into the desired container for placement in a suitable HPHT consolidation and sintering apparatus.

During HPHT processing, a desired catalyst material in powdered form, such as a solvent metal catalyst, can be combined with diamond powder to facilitate diamond bonding during HPHT processing, and/or the catalyst material can be obtained from Infiltration of the substrate is provided. Suitable substrates that may be used as a source for infiltrating catalyst material may include those used to form conventional PCD materials, and may be provided in powder, green state and/or sintered form. This matrix is characterized in that it includes a metal solvent catalyst capable of melting and infiltrating adjacent regions of the diamond powder to facilitate bonding of the diamond grains together during HPHT processing. In an example embodiment, the catalyst material is cobalt (Co), and the substrate that may be used to provide the catalyst material is a cobalt-containing cermet, such as WC—Co.

The diamond powder mixture may be provided in the form of a green state part or mixture comprising diamond powder combined with a binder to provide a suitable product of material, for example, in the form of a diamond ribbon or other formable/suitable diamond mixture product for in the manufacturing process. Where diamond powder is provided in such green state parts, it is desirable to take a preheating step prior to HPHT consolidation and sintering to drive off the binder material. In an exemplary embodiment, the volume content of diamond in the PCD material resulting from the above HPHT treatment may be in the range of about 85% to 95%.

The diamond powder mixture or green state part is loaded into the desired container for placement in a suitable HPHT consolidation and sintering apparatus. The HPHT unit is activated to apply the desired HPHT conditions to the vessel for diamond powder solidification and sintering to occur. In an exemplary embodiment, the apparatus is controlled to subject the container to HPHT treatment at a pressure of 5000 MPa or above and a temperature of from about 1350°C to 1500°C for a predetermined length of time. At this pressure and temperature, the catalyst material melts and infiltrates the diamond powder mixture, sintering the diamond grains to form PCD. When the HPHT treatment is complete, the container is removed from the HPHT unit, and the PCD material so formed is removed from the container.

Where a substrate is used during HPHT processing (eg, as a source of catalyst material), the substrate is removed prior to treating the PCD material to remove the catalyst material therefrom to form the TSP. The matrix may be removed during or after processing to form the TSP. In one embodiment, any matrix is removed prior to processing to speed up the process of removing catalyst material from the PCD body.

The term "removed" as used with respect to the catalyst material forming the TSP after the treatment process should be understood as the absence of a significant portion of said catalyst material in the remaining diamond bonded body. However, it should be understood that some small amounts of catalyst material may still remain in the resulting diamond bonded body, for example in interstitial regions and/or attached to the surface of the diamond crystals. In addition, the term "substantially free" as used herein to refer to the catalyst material in the diamond bonded body after the treatment step should be understood to mean that there may still be residual catalyst material in the TSP material as described above. Some small/trace amounts of catalyst material. Instead of removing the catalyst material from the PCD, the PCD can be made a TSP by treating the catalyst material used to form the PCD so that the catalyst material does not react or catalyze at the operating temperature of the structure.

In an exemplary embodiment, the PCD body is treated such that the entire body is substantially free of catalyst material. This can be achieved by subjecting the PCD body to chemical treatment such as acid leaching or an aqua regia bath, electrochemical treatment such as electrolysis, by liquid metal dissolution or by removing the catalyst material present during liquid phase sintering and replacing it with another This is accomplished by infiltration of liquid metal with replacement of the catalytic material, or by a combination of the above. This process can be performed under conditions of high temperature, high pressure, high frequency vibration and combinations thereof. In an exemplary embodiment, the catalyst material is removed from the PCD body by acid leaching techniques such as disclosed in US Patent No. 4,224,380.

TSPs can be formed using thermally stable catalyst systems such as carbonates, sulfites, or pyrites. In this case, temperatures above 2000° C. and pressures above 7.0 GPa may be required to form the TSP body. In an additional embodiment, the TSP may be formed from a graphitic or non-diamond carbon source, which requires temperatures above 2000°C and pressures above 10.0 GPa.

Figure 1 shows a portion of a diamond-bonded TSP body 10 from which catalyst material has been removed. The TSP body has a material microstructure comprising a polycrystalline diamond matrix phase consisting of a plurality of diamond grains or crystals 12 bonded together, and the bonds are disposed within the matrix due to removal of catalyst material therefrom. A plurality of interstitial regions 14 between adjacent diamond grains, which exist as voids or voids in the material microstructure.

Figure 2 shows an exemplary embodiment of a TSP body 16, wherein the TSP body includes a top surface 22 extending along a diamond table and side surfaces 24 extending along a wall portion of the body. The TSP body includes a working surface, which may include all or a portion of the top and/or sides, depending on the particular end-use application. Although the TSP body shown in FIG. 2 is in the form of a wafer or disk having generally cylindrical sides and flat top and bottom surfaces, it should be understood that TSP bodies of different configurations are intended to be included in the superstructures disclosed herein. Within the bounds of the hard structure. Additionally, the TSP body 16 may include one or more surface features provided to facilitate use of the structure in its end-use application. For example, the TSP body at this stage of processing may include a chamfered or beveled surface portion between its top and sides (eg extending circumferentially around the edge of the top surface), and this surface may be the working surface.

The TSP body so formed is processed prior to being attached to a substrate, which may be in the form of a separate component from the end-use device, such as conventionally used in the manufacture of PCD compacts, or an end-use The form of the device itself. The processing includes applying a layer of metallic material to a surface of the TSP body positioned to interface with the substrate (ie, a substrate interface surface). Said metallic material serves the purpose of increasing the strength of the attachment formed by said brazed joint with said substrate, thereby prolonging the service life by avoiding delamination of the substrate.

In an exemplary embodiment, the TSP body is processed by depositing a metallic material onto the TSP body, said deposition being any suitable deposition process, such as dipping, spraying, chemical vapor deposition (CVD) process, sputtering, etc. . In an exemplary embodiment, the metallic material is desirably a material that includes carbides and/or is a carbide former, eg, a material that forms carbides in subsequent processing. It is desirable to apply the metallic material in a sufficient amount and/or thickness to provide the desired amount of carbides at the substrate interface for the purpose of allowing non-reactive brazing to join the substrate and TSP body together. In some cases, more than one layer of metallic material may be applied to achieve a desired amount or content of carbides on the surface of the TSP body.

In an exemplary embodiment, the metal layer may have a thickness in a range of about 0.1 to 10 microns, in a range of about 0.5 to 5 microns, in a range of about 1 to 3 microns. It should be understood that the exact thickness of the metal layer used will depend on the type of metal material being applied as well as the type of brazing material being used. The treatment may be a treatment that provides a surface coating of a metallic material to the substrate interface surface and/or a treatment that introduces the metallic material into a region of the TSP body extending a fraction of the depth from the substrate interface surface.

Metallic materials that can be used for this treatment may include: metal-containing materials, metals, metal alloys, etc., which either include carbides or form carbides during subsequent processing, such as carbide formers. As mentioned above, the metallic material is used to provide the required amount of carbides on the TSP body to allow the use of non-reactive brazing materials in joining the TSP body to the substrate. The use of these non-reactive brazing materials is desirable because they provide a strong bond to the metal substrate and are superior to traditional reactive brazing materials used in bonding diamond bonded bodies (PCD and TSP) to cermet substrates. In contrast, it has a relatively high yield strength and melting point. As used herein, the term "active brazing" refers to a brazing material that reacts with polycrystalline superhard material (untreated). The term "non-reactive brazing" refers to a brazing material that does not react with the polycrystalline superhard material (untreated).

Suitable carbide-containing metallic materials that can be used for this treatment include B, Si, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W, combinations and alloys thereof. Exemplary carbide-containing metal materials include, but are not limited to, _B4C , SiC, TiC, ZrC, HfC, _VC , NbC, TaC, _Cr2C3 , _CrC2 , _Mo2C , MoC, _W2C , and WC.

Suitable carbide-forming metallic materials that can be used in this process include those that are capable of forming carbides when placed in a carburizing process, which can be performed as a separate step from or during the brazing process. Carburizing treatment. Suitable carbide-forming materials include refractory metals, such as those selected from Groups IV to VII of the Periodic Table of the Elements. In an exemplary embodiment, the metal material is tungsten (W), and the tungsten layer is carburized so that the main component on the interface surface of the substrate is tungsten carbide (WC). The metal material is titanium and the carbide is titanium carbide (TiC).

Metallic materials that can be used for this treatment are desirably those that produce the desired level or content of carbides on the substrate interface surface to facilitate joining the substrate to the TSP body using a non-reactive brazing material. Non-reactive brazing materials are uniquely suited to form a strong bond with carbide-containing surfaces. Thus, treating the TSP body-matrix interface surface in this manner provides a carbide surface on the TSP body that matches the carbides already present on the substrate surface, thereby ensuring Forms a strong brazed connection. Furthermore, because non-reactive brazing materials have relatively higher yield strengths and melting points than reactive brazing materials (typically used to join polycrystalline bodies to metal substrates), brazes formed from such non-reactive brazing materials The combination is less prone to delamination and failure during use, thereby prolonging the service life of the superhard structure formed from it.

The metallic material that can be used to help form the brazed connection between the TSP body and the substrate can also act as a barrier to prevent any unwanted migration or infiltration of material into the TSP body during the brazing operation. In addition, the metal material can help to accommodate any mechanical property mismatch that exists between the TSP body, braze material and substrate, such as differences in thermal expansion properties, which can occur during the attachment process. High residual stresses are generated in the structures described above. This residual stress mismatch can be avoided by using a tungsten or titanium layer with a graded carbide content, for example about 90% or more carbide near the superhard material interface, and at the part to be bonded with a non-active braze. The interface contains 50% or less carbide content.

Figure 3 shows an exemplary embodiment of a superhard structure as described herein, at this stage of processing the layer of metallic material 30 has been applied or deposited onto the substrate interface surface 32 of the TSP body 34 , for subsequent substrate bonding purposes. In an exemplary embodiment, metallic material 30 is tungsten and is provided by a CVD, PVD or sputtering process. The amount of metallic material 30 applied depends on whether a surface coating along the substrate interface surface 32 or an infiltrated region in the TSP body extending a portion of the depth from the substrate interface surface is desired. Whether a surface layer or an infiltrated area is required will depend on factors such as the type of substrate and brazing material used, and the end-use application.

Where TSP cutting edges or work faces require maximum thermal protection, it may be necessary to provide a coated surface treatment. Additional barrier coatings can optimize thermal gradients within the TSP body and thereby extend cut life. In an exemplary embodiment providing a coated surface, the coating can increase the thickness measured from the substrate interface surface of the TSP body by about 1 to 5 microns, about 5 to 20 microns, and greater than about 20 microns.

Treatments that provide infiltrated regions within the TSP body may be required where enhanced attachment strength is required between the substrate and the TSP body, the attachment strength being formed by brazing material (except for the surface of the TSP body). ) in combination with regions of the TSP body comprising said metallic material. In an exemplary embodiment where infiltration of a metallic material is desired, the infiltration depth may be in the range of about 1 to 20 microns.

In embodiments where a metallic material is additionally selected for use as a barrier material, the presence of the metallic material serves to prevent unwanted migration of components from the braze joint and/or matrix into the body of the TSP. Additionally, the presence of this barrier metal material can serve to prevent unwanted infiltration of any material from the body of the TSP into adjacent brazed joints or substrates.

Once the TSP body is processed to include the metallic material, it may be further processed prior to brazing attachment to the substrate. In case the metallic material applied to the TSP body already contains carbides, the TSP body may be brazed without further treatment. Where the metallic material applied to the TSP body is a carbide former and does not yet contain carbides, further processing is required to form the desired carbide composition. In an exemplary embodiment, such further processing may include carburizing the metallic material at an elevated temperature in the range of about 700 to 1500°C. In an exemplary embodiment, the carburizing process is performed at a temperature of about 900° C. for a sufficient time to produce the desired carbides. Temperature and time can also be manipulated to create the desired gradient conditions in the metal layer.

The step of forming said carbide composition in said metallic material, for example by carburizing, may be performed separately and independently from the step of brazing the TSP body to the substrate. The step of forming the carbide composition may be performed during the brazing step, for example immediately before joining the TSP body with the brazing material.

Suitable non-reactive brazing materials described herein that can be used to form superhard structures include those selected from the group consisting of Cu, Ni, Mn, Au, Pd, combinations and alloys thereof. Exemplary alloys include those having the following composition and liquid temperature (LT) and solid temperature (ST) alloys, wherein the composition content is expressed in weight percent: 40Ni, 60Pd, LT = ST = 1238 ° C; 70Au, 22Ni, 8Pd , LT=1037℃, ST=1005℃; 35Au, 31.5Cu, 14Ni, 10Pd, 9.5Mn, LT=1004℃, ST=971℃; 52.5Cu, 9.5Ni, 38Mn, LT=925℃, ST=880℃ ; 31Au, 43.5Cu, 9.75Ni, 9.75Pd, 16Mn, LT=949°C, ST=927°C; 54Ag, 21Cu, 25Pd, LT=950°C, ST=900°C; 67.5Cu, 9Ni, 23.5Mn, LT= 955°C, ST=925°C; 58.5Cu, 10Co, 31.5Mn, LT=999°C, ST=896°C; 35Au, 31.5Cu, 14Ni, 10Pd, 9.5Mn, LT=1004°C, ST=971°C; 25Su, 37Cu, 10Ni, 15Pd, 13Mn, LT=1013°C, ST=970°C; and 35Au, 62Cu, 3Ni, LT=1030°C, ST=1000°C.

The TSP body (including the carbide-containing matrix interface surface) is joined to the substrate by the brazing material under high temperature conditions sufficient to melt the brazing material. The brazed bond may be formed using conventional brazing techniques, such as by vacuum brazing, induction brazing, or the like. It is thus another feature of the superhard structures disclosed herein that the TSP body is attached to the substrate by brazing at high temperature rather than high pressure, ie without subjecting the TSP body to a second HPHT process. It is highly desirable to avoid the need to rely on HPHT processing to attach the TSP body to the substrate, as it increases manufacturing efficiency and reduces associated manufacturing costs, and avoids unwanted bleeding problems.

FIG. 4 illustrates an exemplary embodiment TSP structure 40 that includes a TSP body 42 attached to a substrate 44 by a brazed joint 46 . The TSP body includes working faces, side faces 50 and/or edge faces 52 which may exist along top face 48 . The TSP body includes a substrate interface surface 54 and a metallic material 56 having a carbide composition disposed thereon for providing the same properties as for forming the Enhanced attachment of the non-reactive brazing material of the brazed joint 46 described above.

Exemplary braze materials that can be used to form the braze joint include materials capable of forming a strong chemical bond between the TSP body and the desired substrate. The brazing material desirably includes one or more elements capable of reacting with one or more elements in the TSP body to form this strong chemical bond. For this reason, materials that can be used to form the brazing material may be referred to as "active" brazing materials or alloys.

As noted above, substrates useful in forming superhard structures as described herein may be in the form of a component separate from the end-use device, such as a cermet or carbide component, or may be part of the end-use device itself. form. Accordingly, it should be understood that a TSP body treated in the manner described above may be directly or indirectly attached to the end-use device by the brazing bond described above.

Suitable substrates provided separately from the end-use device may be selected from those materials commonly used as substrates for forming PCD compacts, and may include metallic materials, ceramic materials, cermet materials, and combinations thereof. An exemplary matrix is a carbide matrix, such as a matrix formed of WC—Co. Depending on the size and configuration of the TSP body and the end use application, the size and configuration of the matrix can and will vary. Different types of steel may be used as the matrix, and each type of steel may include or be subsequently machined to include features such as threads or other fastening means to facilitate its mechanical attachment to the drill bit. Among them, the types of steel that can be used as the base include those having a Rockwell hardness C of 50 and above.

Although specific exemplary embodiments of superhard structures have been disclosed and illustrated above, it should be understood that variations of these exemplary embodiments are intended to be within the scope of the disclosure herein.

A superhard structure as described herein is characterized in that the TSP body comprised herein has been treated to comprise a metallic material prior to being attached to the substrate by brazing, wherein such metallic material either comprises or is treated to comprise carbides Element. Another feature of such superhard structures as described herein is that the brazing material used to form said brazing joint is a non-reactive brazing material well suited to form enhanced bond strength between carbide-containing surfaces , because they exist on both the TSP body and the substrate. Another feature of this superhard structure is that the non-reactive brazing material has a relatively high yield strength compared to reactive brazing materials typically used to form the brazed bond between the TSP body and substrate and melting point, thereby extending service life by minimizing undesired delamination during use. Another feature of this superhard structure is that it avoids having to undergo HPHT processing to attach the TSP body to the substrate, wherein the brazing bond is at the melting point of the brazing material without the need for Formed at high pressure, thereby increasing manufacturing efficiency and reducing associated manufacturing costs.

Superhard structures as described herein can be used in a variety of different applications, such as mining, cutting, where shear strength, thermal stability, wear resistance, mechanical strength and/or reduced thermal residual stress are critically needed. , machining, grinding and tools for construction applications. The superhard structures as described herein are particularly well suited for use in forming working, wear and/or cutting elements in machine tools and such as roller cone bits, percussion or vibration bits, diamond bits and Drilling and mining bits with shear cutters.

Figure 5 shows one embodiment of a superhard structure provided in the form of a cutting element as described herein implemented as an insert 60 in a roller cone bit or a percussion or percussion drill bit for use in abrasive or cutting applications . For example, such an insert 60 may be formed from a blank comprising a base portion 62 formed from one or more base materials 64 as described above, and having a thermally stable region formed from the superhard body. The superhard material body 66 of the working face 68 . The blank is extruded or machined into the desired shape of the roller cone bit insert.

FIG. 6 shows a rotary or roller cone bit in the form of a roller cone bit 70 comprising a plurality of wear or cutting inserts 60 as described above and shown in FIG. 5 . The roller cone bit 70 includes a body 72 having three legs 74, and a roller cutting cone 76 mounted to the lower end of each leg. The insert 60 can be manufactured according to the method described above. The inserts 60 are located in the face of each cutting cone 76 to apply pressure to the rock formation being drilled.

FIG. 7 shows an insert 60 as described above for use with a percussion drill bit or hammer bit 80 . The hammer bit comprises a hollow steel body 82 with a threaded pin 84 on one end of the body to mount the bit to a drill string (not shown) for drilling an oil well or the like. A plurality of the inserts 60 (shown in FIG. 7 ) are located in the surface of the head 100 of the body 96 to apply pressure to the subterranean formation being drilled.

Figure 8 shows a superhard structure as described herein implemented in the form of a shear cutter 90 for use with, for example, a drag bit for drilling subterranean formations. The shear cutter 90 includes a thermally stable superhard body 92 sintered or otherwise attached/connected to a cutter base 94 . The body of thermally stable superhard material includes a working or cutting face 96 .

FIG. 9 shows a drag bit 100 including a plurality of shear cutters 90 as described above and shown in FIG. 8 . The shear cutters are each attached to a blade 102 each extending from a head 104 of the drag bit for cutting the subterranean formation being drilled.

While a few exemplary embodiments have been described above, those skilled in the art will readily appreciate that various modifications can be made to the exemplary embodiments without materially departing from the scope of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the claims. In the claims, clauses of functional means are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although nails and screws may not be structurally equivalent in that nails have cylindrical surfaces for fastening wooden parts and screws have helical surfaces, in the context of fastening wooden parts nails and screws may be equal price structure. It is Applicant's express intent not to invoke 35 U.S.C. §112, paragraph 6, for any limitation of any claim herein, except where the claim expressly uses the words "means for" and the associated function.

Claims (23)

1. A superhard structure (40), comprising: a diamond bonded body (42) comprising a matrix phase of diamond grains bonded together, wherein the body is thermally stable at temperatures above about 750°C; a metallic material (56) disposed on the matrix interface surface (54) of the diamond bonded body, the metallic material having a carbide composition; and A base body (44) is connected to the diamond bonded body (42) by a brazed joint (46) interposed between the metallic material (56) and the base body (44). 2. The structure of claim 1, wherein said diamond bonded body further comprises a plurality of interstitial regions interposed between said bonded diamond grains, said interstitial regions being substantially free of / Catalyst material for sintering diamond bonded bodies under high temperature conditions. 3. The structure of claim 1, wherein the diamond bonded body comprises a material synthesized using carbonate material under high pressure and temperature conditions. 4. The structure of claim 1, wherein the metallic material includes a carbide composition and the matrix includes a carbide composition. 5. The structure of claim 1, wherein the brazed joint is formed from a non-reactive brazing material that reacts with the substrate and metallic material. 6. The structure of claim 1, wherein the layer thickness of the metallic material is in the range of about 0.1 to 10 microns. 7. The structure of claim 5, wherein the non-reactive brazing material is selected from the group consisting of Cu, Ni, Mn, Au, Pd, combinations and alloys thereof. 8. A cutting element for drilling a subterranean formation, said cutting element comprising the superhard structure of claim 1. 9. A drill bit for drilling a subterranean formation comprising a body and a plurality of cutting elements as claimed in claim 8 operably attached to said body. 10. A superhard structure (40) prepared by the following process: forming a diamond bonded body (42) under high pressure/high temperature conditions, the diamond bonded body comprising a matrix phase of diamond grains bonded together, the body being thermally stable at temperatures above about 750°C; Treating the diamond bonded body (42) to include a metallic material (56) on a substrate interface surface (54), wherein the metallic material (56) is selected from the group consisting of carbide-containing materials and carbide-forming materials ;as well as attaching a metal matrix (44) to the diamond bonded body (42), wherein the metal matrix (44) is attached to the diamond bonded body (42) at high temperature rather than high pressure using a brazed joint (46) Ontology (42). 11. The structure of claim 10, wherein the diamond bonded body includes a plurality of interstitial regions interposed between the bonded diamond grains. 12. The structure of claim 10, wherein in said forming step a carbonate material is used. 13. The structure of claim 11, wherein the diamond bonded body is treated such that the interstitial region is substantially free of catalyst material used to form the diamond bonded body under high pressure/high temperature conditions. 14. The structure of claim 10, wherein the metallic material is a carbide forming material, the process further comprising the step of carburizing the metallic material to provide a carbide composition. 15. The structure of claim 14, wherein the step of carburizing is performed at a temperature above about 900°C. 16. The structure of claim 10, wherein the brazed joint is formed of a non-reactive brazing material that reacts with carbides in the substrate and the substrate interface surface to provide a gap between the substrate and the substrate interface surface. A strong bond is formed, wherein the elevated temperature is about the melting point of the non-reactive brazing material. 17. A method for manufacturing a superhard structure (40), comprising the steps of: forming a diamond bonded body (42) comprising a matrix phase of diamond grains bonded together under high pressure/high temperature conditions, the body (42) being thermally stable at temperatures above about 750°C; treating the substrate interface surface (54) of the diamond bonded body (42) to include a layer of metallic material (56) on the substrate interface surface; and attaching a metal matrix (44) to a diamond bonded body (42), wherein said metal material (56) comprises a carbide composition prior to said attaching step in which brazing material Melted under non-high pressure conditions and forms a brazed joint (46). 18. The method of claim 17, wherein the matrix includes a carbide composition and the brazing material is a non-reactive brazing material. 19. The method of claim 17, wherein, in the forming step, a carbonate material is used. 20. The method of claim 17, wherein said body includes a plurality of interstitial regions interposed between said bonded diamond grains, wherein said interstitial regions are substantially free of Catalyst material forming said diamond bonded body under high temperature conditions. 21. The method of claim 17, wherein, in the step of treating, the metallic material is a carbide-forming material, the method further comprising infiltrating the metallic material at a temperature greater than about 900° C. carbon step to provide carbide components. 22. The method of claim 21, wherein the carburizing step is performed separately from the attaching step. 23. The method of claim 17, wherein the attaching step is performed in a vacuum environment at a temperature between about 900 and 1200°C.