ULTRA-HARD MATERIAL CUTTING ELEMENTS, METHODS OF FORMING THE SAME AND BITS INCORPORATING THE SAME
The present disclosure relates to cutting tools incorporating polycrystalline diamond bodies used for subterranean drilling applications, and more particularly, to a polycrystalline diamond body joined to a substrate by a fastening member to form a cutting element. The polycrystalline diamond body may be binderless polycrystalline diamond, non-metal catalyst polycrystalline diamond, leached polycrystalline diamond, carbonate polycrystalline diamond or polycrystalline cubic boron nitride. The polycrystalline diamond body includes an aperture and a fastening member extending through the aperture and metallurgically bonded to the substrate by a HPHT process.
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This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/717,070 filed on Oct. 22, 2012, which is incorporated herein by reference in its entirety.
BACKGROUNDUltra-hard materials are often used in cutting tools and rock drilling tools. Polycrystalline diamond material is one such ultra-hard material, and is known for its good wear resistance and hardness, making it a popular material choice for use in such industrial applications as cutting tools for machining and wear and cutting elements in subterranean mining and drilling.
To form polycrystalline diamond, diamond particles are sintered at high pressure and high temperature (HPHT sintering) to produce an ultra-hard polycrystalline structure. A catalyst material may be added to the diamond particle mixture prior to sintering and/or infiltrates the diamond particle mixture during sintering in order to promote the intergrowth of the diamond crystals during HPHT sintering, to form the polycrystalline diamond (PCD) structure. Metals conventionally employed as the catalyst are selected from the group of solvent metal catalysts selected from Group VIII of the Periodic table, including cobalt, iron, and nickel, and combinations and alloys thereof. After HPHT sintering, the resulting PCD structure includes a network of interconnected diamond crystals bonded to each other, with the catalyst material occupying the interstitial spaces or pores between the bonded diamond crystals. The diamond particle mixture may be HPHT sintered in the presence of a substrate, to form a PCD body bonded to the substrate. The substrate may also act as a source of the metal catalyst that infiltrates into the diamond particle mixture during sintering.
A desired property of PCD bodies used for certain applications is improved thermal stability during wear or cutting operations. A problem known to exist with conventional PCD bodies is that they are vulnerable to thermal degradation when exposed to elevated temperatures. This vulnerability results from the differential that exists between the thermal expansion characteristics of the solvent metal catalyst material disposed interstitially within the PCD body and the thermal expansion characteristics of the intercrystalline bonded diamond. The material damage caused by such differential thermal expansion is known to start at temperatures as low as 400° C., and can induce thermal stresses that can be detrimental to the intercrystalline bonding of diamond and eventually result in the formation of cracks that can make the PCD structure vulnerable to failure. Further, the solvent metal catalyst is known to cause an undesired catalyzed phase transformation in diamond (converting it to graphite) with increasing temperature, thereby limiting practical use of the PCD body to about 750° C.
Thermally stable PCD materials have been developed to improve performance at high temperatures. However, it can be difficult to form a bond between the thermally stable PCD material and a substrate, for attachment to a cutting tool. Due to the high brittleness and high hardness of thermally stable PCD materials, machining conventional features, such as threads, on the PCD body or the carbide is not feasible. Accordingly, it is difficult to join the thermally stable PCD material and a substrate by conventional mechanical methods.
SUMMARYThe present disclosure relates to cutting tools incorporating polycrystalline diamond bodies used for subterranean drilling applications, and more particularly, to a thermally stable polycrystalline diamond (PCD) body joined to a substrate by one or more fastening elements to form a cutting element. In an embodiment, a cutting element includes a thermally stable polycrystalline diamond body mechanically joined to a carbide substrate with a fastening element. The thermally stable PCD body may be binderless PCD, non-metal catalyst PCD such as a carbonate PCD, or leached PCD. In an embodiment, a method is provided for joining a thermally stable polycrystalline diamond body to a substrate. The method includes forming a thermally stable PCD body, which may be binderless PCD, non-metal catalyst PCD, or leached PCD. The method includes forming an aperture in the thermally stable PCD body for receiving the fastening element, and inserting the fastening element into the aperture. The method also includes positioning the thermally stable PCD body and fastening element on the substrate. The method also includes subjecting the thermally stable PCD, the fastening element, and the substrate to high pressure high temperature (HPHT) sintering to bond the fastening member to the substrate.
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 in limiting the scope of the claimed subject matter.
Embodiments of thermally stable PCD materials mechanically fastened to substrates are described with reference to the following figures. The same numbers are used throughout the figures to reference like features and components.
The present disclosure relates to cutting tools, such as shear cutters on a drill bit, incorporating polycrystalline diamond bodies used for subterranean drilling applications, and more particularly, to a thermally stable polycrystalline diamond (PCD) body joined to a substrate by one or more fastening elements to form a cutting element. In an embodiment, the thermally stable PCD material may be binderless PCD, non-metal catalyst PCD, or leached PCD. The thermally stable PCD body includes an aperture to receive the fastening element securing the thermally stable PCD body to the substrate. The fastening element is subsequently metallurgically bonded to the substrate to mechanically fasten the PCD body to the substrate. The fastening element may also be metallurgically bonded to the PCD body.
The following disclosure is directed to various embodiments. The embodiments disclosed have broad application, and the discussion of any embodiment is meant only to be descriptive of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment or to the features of that embodiment.
Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art would appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name only. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness.
As used herein, a plurality of items, structural elements, compositional elements and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary.
Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.
For clarity, as used herein, the term “conventional PCD” refers to conventional polycrystalline diamond that has been formed with the use of a conventional metal catalyst during an HPHT sintering process, forming a microstructure of bonded diamond crystals with the metal catalyst material occupying the interstitial spaces or pores between the bonded diamond crystals.
“Non-metal catalyst PCD” refers to PCD material that has been formed with the use of a non-metal catalyst during an HPHT sintering process, forming a microstructure of bonded diamond crystals with the non-metal catalyst material occupying the interstitial spaces or pores between the bonded diamond crystals. Examples of non-metal catalysts include carbonates (e.g., MgCO3), sulfates (e.g., MgSO4), hydroxides (e.g., Mg(OH)2), and iron oxides (e.g., FeTiO3). A carbonate catalyst may be any Group I or Group II carbonate, such as magnesium carbonate, calcium carbonate, lithium carbonate, or sodium carbonate, or combinations of carbonates. “Binderless PCD” refers to a polycrystalline diamond matrix that is formed without the use of a catalyst, such as by converting graphite directly to diamond at ultra-high pressure and temperatures. “Leached PCD” refers to a PCD material that has been treated following the HPHT sintering process to remove at least a portion of the catalyst material formed in the interstitial regions between the bonded diamond crystals and, thus, comprises a plurality of interstitial regions that are substantially free of the catalyst material (i.e., the interstitial regions between the bonded diamond crystals are substantially empty voids or pores). “Thermally stable PCD” as used herein means non-metal catalyst PCD, binderless PCD or leached PCD. In an embodiment, the thermally stable PCD is selected from the group consisting essentially of non-metal catalyst PCD, binderless PCD, and leached PCD. Examples of suitable devices for performing the HPHT sintering process include a cubic press, a belt press, and a toroid press.
A region of non-metal catalyst PCD material 10 is schematically illustrated in
A region of binderless PCD material 20 is schematically illustrated in
In one embodiment the material microstructure of the binderless PCD material 20 has a diamond volume content of at least 98%, and in another embodiment at least or about 99%, and in another embodiment at least or about 99.5%, and in another embodiment at least or about 99.8%, and in another embodiment at least or about 99.9%. In one embodiment, the binderless PCD material 20 has a fine diamond grain size, such as an average diamond grain size less than 1 micron, such as about 50 nm or less. In other embodiments, the binderless PCD material 20 has an average grain size of about 1-30 microns.
In another embodiment, the thermally stable binderless diamond material is formed by depositing layers in a chemical vapor deposition (CVD) process, to form a binderless PCD material 20 with substantially 100% diamond volume content. The CVD process is performed by heating gas precursors in a reactive environment, which results in the precursors reacting or decomposing on the surface of a substrate, forming the desired deposit. This process results in growth of diamond crystals on the substrate.
Binderless PCD is thermally stable because it does not suffer from differential thermal expansion between diamond and catalyst. The binderless PCD has one phase, and thus there is no differential thermal expansion between different phases of the material. As a result, diamond bodies formed from this binderless PCD material can exhibit high strength even at elevated temperatures, whereas conventional PCD suffers from thermal degradation due to the differential expansion of the diamond and catalyst phases.
A region of leached PCD material 30 is schematically illustrated in
During a mining or drilling operation, shear cutters on the drill bit may experience high loads (e.g., between 2500 and 3000 lbs on a cutting edge of the shear cutters). Accordingly, forming a strong bond between the thermally stable PCD body and the substrate may enable the shear cutters to withstand these high loads. Bonding a thermally stable PCD body to a substrate can present a challenge because a thermally stable PCD body is formed without a conventional catalyst metal, such as cobalt. In a conventional PCD, the metal solvent catalyst used to facilitate diamond growth during HPHT sintering also forms a bond between the conventional PCD body and the substrate. In contrast, a thermally stable PCD body lacks a metal solvent catalyst to form a bond between the thermally stable PCD body and the substrate. Non-metal catalyst PCD includes non-metal catalyst occupying the interstitial spaces (see
According to an embodiment illustrated in
In an embodiment, the cutting element 40 is formed in two separate HPHT sintering processes. In one embodiment, the cutting element 40 is formed by pre-forming the thermally stable PCD body 41 in a first HPHT sintering process and subsequently joining the thermally stable PCD body 41 to the substrate 42 via a fastening member 43 in a second HPHT sintering process (i.e., the thermally stable PCD body 41 is first formed by HPHT sintering before a second HPHT bonding process is performed to secure the thermally stable PCD body 41 to the substrate 42). The thermally stable PCD body 41 formed in the first HPHT sintering process may be either non-metal catalyst PCD (such as carbonates, sulfates, hydroxides and iron oxides), binderless PCD, or leached PCD. In an embodiment, the first HPHT sintering process is performed on a pre-sintered or pre-compacted PCD body to form the thermally stable PCD body 41. An aperture 48 is subsequently formed in the thermally stable PCD body 41 to receive the fastening member 43 joining the thermally stable PCD body 41 to the substrate 42. In the embodiment illustrated in
With continued reference to an embodiment illustrated in
In an embodiment illustrated in
After the apertures 48, 51 have been formed in the thermally stable PCD body 41 and the substrate 42, respectively, the thermally stable PCD body 41 is positioned on top of the substrate 42 in a stacked configuration such that the aperture 48 in the thermally stable PCD body 41 is axially aligned with the aperture 51 in the substrate 42, as illustrated in
During the second HPHT process, the fastening member 43 becomes ductile and tends to flow from higher pressure regions to lower pressure regions. In one embodiment, the shaft 55 of the pin 43 can radially expand under the pressure and flow into the apertures 48, 51 in the thermally stable PCD body 41 and the substrate 42, respectively. In this manner, the second HPHT process results in a metallurgical bond between the fastening member 43 and the substrate 42 at the interface between the shaft 55 and the aperture 51 in the substrate 42. Specifically, a metallurgical bond is formed between the outer surface of the shaft 55 and the sidewall 53 of the aperture 51 in the substrate 42, and between the lower surface 58 of the shaft 55 and the lower surface 52 of the aperture 51 in the substrate 42. Depending on the conditions of the second HPHT process, a metallurgical bond may also form at the interface between the thermally stable PCD body 41 and the fastening member 43. In an embodiment, the carbide fastening member 43 becomes ductile during the second HPHT process and a portion of the fastening member 43 infiltrates into the interstitial regions between the bonded diamond crystals of the thermally stable PCD body 41. In one or more embodiments, the cobalt binder matrix of the fastening member 43 enters a liquid state during the second HPHT process and impregnates or infiltrates the interstitial regions disposed between the bonded diamond crystals of the PCD body 41, thereby forming a metallurgical bond between the fastening member 43 and the PCD body 41. Additionally, in one embodiment, a bond may form between the thermally stable PCD body 41 and the carbide substrate 42 along the respective interface surfaces 45, 50. Accordingly, the bond formed between the fastening member 43 and the substrate 42 mechanically secures the thermally stable PCD body 41 to the substrate 42. Moreover, the abutment of the head portion 54 of the fastening member 43 against the working surface 44 of the thermally stable PCD body 41 provides a compressive force securing the thermally stable PCD body 41 to the substrate 42.
The metallurgical bonds described above also avoid sharp contact points and areas of high stress concentration between the fastening member 43, the PCD body 41 and the substrate 42, which could otherwise result from joining an ultra-hard body to a substrate. Because the carbide fastening member 43 and substrate 42 may become ductile during the HPHT process, the carbide may flow and fill in any gaps between the PCD body 41 and the fastening member 43, the PCD body 41 and the substrate 42, and the fastening member 43 and the substrate 42. Accordingly, the flow of the carbide into the various gaps during the HPHT process tends to create smooth interfaces between the PCD body 41, the fastening member 43, and the substrate 42, thereby preventing sharp point or line contacts between the respective parts of the cutting element 40.
Although the PCD body 41 and the substrate 42 are illustrated with planar interface surfaces 45, 50, respectively, the interface surfaces may be non-planar. In one or more embodiments, the interface surface 50 of the substrate 42 may include one or more protrusions (e.g., a domed surface), and the interface surface 45 of the PCD body 41 may include one or more corresponding depressions (e.g., a concave groove) for receiving the protrusions. The protrusions and depressions are configured to join the PCD body 41 to the substrate 42.
In an embodiment illustrated in
An aperture 78 is subsequently formed in the thermally stable PCD body 71 to receive the fastening member 73 securing the thermally stable PCD body 71 to the substrate 72. In an embodiment illustrated in
In the embodiment illustrated in
With continued reference to the embodiments illustrated in
In an embodiment illustrated in
After the notch 78 has been formed in the thermally stable PCD body 71, the clamp 73 is seated in the notch 78 with the lip 92 and the flange 82 in an interlocking or lap joint configuration, as illustrated in
The thermally stable PCD body 71 and clamp 73 are subsequently positioned on the interface surface 95 of the substrate 72. Together, the thermally stable PCD body 71 and the clamp 73 are substantially coextensive with the interface surface 95 of the substrate 72. Subsequently, the thermally stable PCD body 71, the clamp 73 and the substrate 72 are placed into a press (e.g., a cubic press, a belt press, a toroid press, etc.) and a second HPHT process is then performed to mechanically secure the thermally stable PCD body 71 to the substrate 72 with the clamp 73. In an embodiment, the second HPHT process may be performed at pressures ranging between approximately 5.5 GPa and 7 GPa and temperatures ranging between approximately 1340° C. and 1550° C. In another embodiment, the second HPHT process may be performed at approximately 5 GPa. In one embodiment, the temperature and pressure applied during the HPHT process to bond the clamp 73 to the substrate 72 are substantially similar to the temperature and pressure applied during the HPHT sintering process forming the thermally stable PCD body 71. During the second HPHT process, a metallurgical bond is formed between the clamp 73 and the substrate 72 along the interface surface 90 of the clamp 73. Depending on the conditions of the second HPHT process, a metallurgical bond may also form at the interface between the thermally stable PCD body 71 and the clamp 73. In an embodiment, the carbide clamp 73 becomes ductile during the second HPHT process and a portion of the clamp 73 infiltrates into the interstitial regions between the bonded diamond crystals of the thermally stable PCD body 71, thereby forming the metallurgical bond between the PCD body 71 and the clamp 73. Additionally, in one embodiment, a bond may form between the thermally stable PCD body 71 and the carbide substrate 72 along the respective interface surfaces 75, 95. Accordingly, the metallurgical bond between the clamp 73 and the substrate 72, and the interlocking configuration of the clamp 73 and the notch 78, mechanically secure the thermally stable PCD body 71 to the substrate 72.
In another embodiment illustrated in
In the illustrated embodiment of
With continued reference to
After the tapered wedge 133 is positioned in the opening 138 in the PCD body 131, the tapered wedge 133 and the PCD body 131 are then stacked on an interface surface 142 of the substrate 132. In one embodiment, the tapered flange 139 does not extend entirely to the sidewall 136 of the PCD body 131 such that an interface surface portion 143 of the tapered wedge 133 which is not tapered rests on the interface surface 142 of the substrate 132. A second HPHT process is subsequently performed to mechanically secure the thermally stable PCD body 131 to the substrate 132 with the tapered wedge 133. The second HPHT process may be performed at pressures ranging between approximately 5.5 GPa and 7 GPa and temperatures ranging between approximately 1340° C. and 1550° C. During the second HPHT process, a metallurgical bond is formed between the tapered wedge 133 and the substrate 132 along the interface surfaces 142, 143 of the substrate 132 and the tapered wedge 133, respectively. Depending on the conditions of the second HPHT process, a metallurgical bond may also form at the interface between the thermally stable PCD body 131 and the tapered wedge 133, and between the thermally stable PCD body 131 and the substrate 132 along the respective interface surfaces 135, 142. Accordingly, the metallurgical bond between the tapered wedge 133 and the substrate 132, and the overlapping configuration of the tapered wedge 133 and the tapered flange 139, mechanically secure the thermally stable PCD body 131 to the substrate 132.
In an embodiment illustrated in
In an embodiment, the cutting element 100 is formed by pre-forming the thermally stable PCD body 101 in a first HPHT sintering process and subsequently mechanically joining the thermally stable PCD body 101 to the substrate 102 with the fastening member 103 in a second HPHT sintering process. The thermally stable PCD body 101 formed in the first HPHT sintering process may be either non-metal catalyst PCD (such as carbonates, sulfates, hydroxides and iron oxides), binderless PCD, or leached PCD, as described above.
Apertures 110, 111 are subsequently formed in the thermally stable PCD body 101 and the substrate 102, respectively, to receive the fastening member 103 rotatably joining the thermally stable PCD body 101 to the substrate 102. In an embodiment, the aperture in the thermally stable PCD body 101 is comprised of an axial through hole 110 extending along the longitudinal axis 109 of the cutting element 100, and the aperture in the substrate 102 is a generally cylindrical recess 111 concentric with the axial through hole 110. The cylindrical recess 111 in the substrate 102 is comprised of a lower surface 112 and a sidewall 113 extending between the lower surface 112 and the interface surface 114 of the substrate 102.
In an embodiment illustrated in
In an embodiment illustrated in
After the apertures 110, 111 have been formed in the thermally stable PCD body 101 and the substrate 102, respectively, and the ball bearings 116 have been inserted into the hemispherical depressions 115, the thermally stable PCD body 101 is positioned on top of the substrate 102 and the apertures 110, 111 are axially aligned. When the thermally stable PCD body 101 is positioned on the substrate 102, the interface surface 105 of the thermally stable PCD body 101 rotatably contacts a portion of the ball bearings 116, as illustrated in
In an embodiment, a small gap may exist between the bottom surface 120 of the head portion 117 of the pin 103 and the working surface 104 of the thermally stable PCD body 101. The gap is configured to permit the thermally stable PCD body 101 to rotate (arrow 108) about the pin 103 during operation. In another embodiment, the bottom surface of the head portion of the fastening member abuts the working surface of the thermally stable PCD body. Similarly, an annular gap may be formed between the pin 103 and the through hole 110 such that the thermally stable PCD body 101 is configured to rotate (arrow 108) about the pin 103 during operation. Additionally, the bottom surface 121 of the shaft 118 of the pin 103 abuts the lower surface 112 of the cylindrical recess 111 in the substrate 102, as shown in
Subsequently, the thermally stable PCD body 101, the pin 103, and the substrate 102 are placed into a press (e.g., a cubic press, a belt press, a toroid press, etc.) and a second HPHT process (e.g., pressures ranging between approximately 5.0 GPa and 5.5 GPa, and temperatures ranging between approximately 1300° C. and 1350° C.) is then performed to rotatably join the thermally stable PCD body 101 to the substrate 102 with the pin 103. During the second HPHT process, the pin 103 becomes ductile and a metallurgical bond is formed between the pin 103 and the substrate 102 at the interface between the shaft 118 and the cylindrical recess 111 in the substrate 102. Accordingly, the metallurgical bond formed between the pin 103 and the substrate 102 mechanically secures the thermally stable PCD body 101 to the substrate 102. Moreover, the interface surface 105 of the thermally stable PCD body 101 is slidably engaged with the plurality of bearings 116 recessed in the substrate 102 such that the thermally stable PCD body 101 is rotatably joined to the substrate 102. Accordingly, the PCD body 101 is configured to rotate (arrow 108) about pin 103 during a drilling or mining operation using the cutting element 100. Additionally, insulation in powder or tape form may be provided during the second HPHT process to avoid creating a bond between the pin 103 and the PCD body 101 or between the PCD body 101 and the ball bearings 116, which would tend to resist rotation (arrow 108) of the PCD body 101 relative to the substrate 102. The insulation may comprise any composition which does not react with cobalt under the pressure and temperature conditions of the second HPHT process, such as boron nitride (h-BN) or aluminum oxide (Al2O3). The insulation may be removed after the second HPHT process to permit free rotation (arrow 108) of the PCD body 101.
The pin 103 may be selected from the group including metallic materials, ceramic materials, cermet materials and combinations thereof. Examples include carbides such as WC, W 2 C, TiC, VC. In an embodiment, the pin 103 is formed of cemented tungsten carbide. Similarly, the substrate 102 can be selected from the group including metallic materials, ceramic materials, cermet materials and combinations thereof, such as WC, W 2 C, TiC, VC. In one embodiment, the substrate 102 is formed of cemented tungsten carbide. In an embodiment, the pin 103 and the substrate 102 are formed from substantially similar materials, although the pin 103 and the substrate 102 may be formed from dissimilar materials and still fall within the scope and spirit of the present disclosure. In one embodiment, the pin 103 and the substrate 102 may be formed from cemented tungsten carbide.
In one embodiment, the cutting element 100 may include a retaining plate 150 disposed between the PCD body 101 and the substrate 102, as illustrated in
A method 200 of joining a thermally stable PCD body to a substrate is shown in
The method 200 also includes forming an aperture (such as an axial through hole, a stepped notch or any other suitably shaped opening) in the thermally stable PCD 250, such as by laser cutting or electrical discharge machining (EDM). Forming the aperture in the thermally stable PCD body 250 may include forming a hole 260 or forming a notch 270 in the thermally stable PCD body. In an embodiment, the method 200 may also include forming an aperture in the substrate, such as by milling or machining. The method 200 may also include forming a fastening member, such as a pin or a notched clamp. The fastening member may be formed by any suitable process, such as extrusion or HPHT sintering.
The method 200 also includes inserting the fastening member into the aperture (e.g., an axial through hole or a stepped notch) in the thermally stable PCD body 280. The method 200 also includes bonding the fastening member to a substrate 290, thereby joining the thermally stable PCD body to the substrate. In an embodiment, forming the thermally stable PCD body is performed in a first HPHT sintering process and bonding the fastening element with the substrate is performed in a subsequent second HPHT sintering process. In an embodiment, bonding the fastening element with the substrate 290 includes placing the thermally stable PCD body, the fastening member, and the substrate in a press (e.g., a cubic press, a belt press, a toroid press, etc.) and performing an HPHT process (e.g., pressures ranging between approximately 5.5 GPa and 7 GPa, and temperatures ranging between approximately 1340° C. and 1550° C.).
A method 300 of joining a thermally stable PCD body to a substrate is shown in
In an embodiment, the method 300 includes inserting a plurality of ball bearings into the plurality of hemispherical depressions. The method 300 also includes inserting the fastening member into the aperture in the thermally stable PCD body and the aperture in the substrate 340. The method 300 also includes bonding the fastening member to the substrate 350, thereby joining the thermally stable PCD body to the substrate to form the cutting element. In an embodiment, bonding the fastening element with the substrate 350 includes placing the thermally stable PCD body, the fastening member, and the substrate in a press (e.g., a cubic press, a belt press, a toroid press, etc.) and performing an HPHT process (e.g., pressures ranging between approximately 5.5 GPa and 7 GPa, and temperatures ranging between approximately 1340° C. and 1550° C.). In an embodiment, the thermally stable PCD body is rotationally joined to the substrate.
While in one embodiment, the method 200, 300 of joining a thermally stable PCD body to a substrate may include each of the tasks described above and shown in
The ultra-hard bodies shown in
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 disclosure. 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. Moreover, although the present disclosure has described a fastening member for mechanically joining a thermally stable polycrystalline diamond (PCD) body (such as binderless PCD, non-metal catalyst PCD, and leached PCD) to a substrate, those skilled in the art will appreciate that the present disclosure applies equally to polycrystalline diamond (PCD) bodies and polycrystalline cubic boron nitride (PCBN) bodies. In addition, the thermally stable polycrystalline diamond (PCD) body may be formed with a thermally compatible silicon carbide binder. Additionally, in one embodiment, only a portion of the polycrystalline diamond (PCD) body is thermally stable PCD. For instance, only a portion of the PCD body may be leached and the remainder of the PCD body may be conventional PCD (e.g., the working surface of the PCD body may be leached PCD and the interface surface of the PCD body may be conventional PCD).
Claims
1. A cutting element, comprising:
- a polycrystalline diamond body having a working surface and an interface surface opposite the working surface; an aperture in the polycrystalline diamond body extending between the working surface and the interface surface; a substrate having an interface surface; a fastening element extending through the aperture in the polycrystalline diamond body; and a metallurgical bond between at least a portion of the fastening element and at least a portion of the substrate at an interface between the fastening element and the substrate.
2. The cutting element of claim 1, wherein the polycrystalline diamond body is selected from the group of bodies consisting essentially of binderless polycrystalline diamond bodies, non-metal catalyst polycrystalline diamond, leached polycrystalline diamond, carbonate polycrystalline diamond, and polycrystalline cubic boron nitride.
3. The cutting element of claim 1, wherein at least a portion of the polycrystalline diamond body is selected from the group of bodies consisting essentially of binderless polycrystalline diamond bodies, non-metal catalyst polycrystalline diamond, leached polycrystalline diamond, carbonate polycrystalline diamond, and polycrystalline cubic boron nitride.
4. The cutting element of claim 1, wherein the fastening member comprises a first carbide material and the substrate comprises a second carbide material, the first carbide material being different than the second carbide material.
5. The cutting element of claim 1, wherein the fastening member comprises a first carbide material and the substrate comprises a second carbide material, the first carbide material being the same as the second carbide material.
6. The cutting element of claim 1, wherein the fastening member comprises a cemented tungsten carbide material having a cobalt binder matrix.
7. The cutting element of claim 1, wherein the metallurgical bond is formed by high pressure high temperature sintering producing a pressure between approximately 5.5 GPa and 7 GPa and a temperature between approximately 1340° C. and 1550° C.
8. The cutting element of claim 1, further comprising a metallurgical bond between at least a portion of the fastening member and at least a portion of the polycrystalline diamond body.
9. The cutting element of claim 1, wherein the aperture is a hole extending between the working surface and the interface surface of the polycrystalline diamond body.
10. The cutting element of claim 9, further comprising a cylindrical recess in the carbide substrate extending down from the interface surface of the substrate, wherein the fastening element is a pin having a head portion and a shaft portion extending from the head portion, the shaft portion extending through the hole and into the cylindrical recess, and the head portion overhanging a portion of the working surface.
11. The cutting element of claim 1, wherein the aperture is a notch extending along at least a portion of the periphery of the polycrystalline diamond body.
12. The cutting element of claim 11, wherein the fastening element is a wedge-shaped clamp generally complementary to the notch.
13. The cutting element of claim 1, further comprising:
- a plurality of hemispherical depressions in the interface surface of the substrate, wherein the depressions are disposed in a circular pattern; and
- a plurality of ball bearings housed in the hemispherical depressions, wherein the interface surface of the thermally stable polycrystalline body is slidably engaged with the plurality of ball bearings such that the polycrystalline diamond body is rotatably joined to the substrate.
14. A drill bit comprising a body having a cutting element as in claim 1 mounted thereon.
15. A method of joining a thermally stable polycrystalline diamond body to a substrate with a fastening member, the method comprising:
- obtaining a thermally stable polycrystalline diamond body having an aperture, wherein the thermally stable polycrystalline diamond body is selected from the group of bodies consisting essentially of binderless polycrystalline diamond bodies, non-metal catalyst polycrystalline diamond bodies, leached polycrystalline diamond bodies, carbonate polycrystalline diamond, and polycrystalline cubic boron nitride;
- obtaining a substrate;
- inserting the fastening member into the aperture; and
- high pressure, high temperature sintering the fastening member, the thermally stable polycrystalline diamond body, and the substrate to form a metallurgical bond between the fastening member and the substrate.
16. The method of claim 15, wherein obtaining the thermally stable polycrystalline diamond body comprises forming the thermally stable polycrystalline diamond body and forming the aperture in the thermally stable polycrystalline diamond body.
17. The method of claim 16, wherein obtaining the thermally stable polycrystalline diamond body comprises sintering diamond particles and a non-metal catalyst at high temperature and high pressure to form non-metal catalyst polycrystalline diamond.
18. The method of claim 16, wherein obtaining the thermally stable polycrystalline diamond body comprises subjecting carbon to an ultra-high pressure, high temperature sintering process without a catalyst material, to form binderless polycrystalline diamond.
19. The method of claim 16, wherein obtaining the thermally stable polycrystalline diamond body comprises:
- subjecting diamond powder and a catalyst to a high pressure, high temperature sintering process to form a polycrystalline diamond body; and
- treating a portion of the polycrystalline diamond body to remove a substantial portion of the catalyst material in interstitial regions between the bonded diamond crystals to form leached polycrystalline diamond.
20. The method of claim 15, wherein high pressure, high temperature sintering the fastening member, the thermally stable polycrystalline diamond body, and the substrate to form a metallurgical bond between the fastening member and the substrate comprises producing a pressure between approximately 5.5 GPa and 7 GPa and a temperature between approximately 1340° C. and 1550° C.
Type: Application
Filed: Mar 15, 2013
Publication Date: Apr 24, 2014
Applicant: SMITH INTERNATIONAL, INC. (HOUSTON, TX)
Inventor: FENG YU (LINDON, UT)
Application Number: 13/837,609
International Classification: E21B 10/573 (20060101); E21B 10/50 (20060101); B24D 18/00 (20060101); E21B 10/55 (20060101);