Cutting elements for earth-boring tools, earth-boring tools including such cutting elements, and methods of forming cutting elements for earth-boring tools
09931736 ยท 2018-04-03
Assignee
Inventors
Cpc classification
B24D3/007
PERFORMING OPERATIONS; TRANSPORTING
B24D18/0072
PERFORMING OPERATIONS; TRANSPORTING
International classification
E21B10/46
FIXED CONSTRUCTIONS
B24D18/00
PERFORMING OPERATIONS; TRANSPORTING
B24D3/00
PERFORMING OPERATIONS; TRANSPORTING
B23F21/06
PERFORMING OPERATIONS; TRANSPORTING
Abstract
Cutting elements for use with earth-boring tools include a cutting table having a base surface and a substrate having a support surface. An intermediate structure and an adhesion layer extend between the base surface of the cutting table and the support surface of the substrate. Earth-boring tools include such cutting elements. Methods for fabricating cutting elements for use with earth-boring tools include forming an intermediate structure on and extending from a support surface of a substrate and adhering a cutting table comprising a superabrasive material to the support surface of the substrate.
Claims
1. A method for fabricating a cutting element for use with an earth-boring tool, comprising: forming an intermediate structure comprising a plurality of discrete protrusions on and extending from a support surface of a substrate positioned within an outer boundary of the support surface of the substrate; positioning a planar base surface of a cutting table comprising a superabrasive material directly on the plurality of protrusions and over the support surface of the substrate to define voids between the support surface of the substrate and the planar base surface of the cutting table, the cutting table having a cutting surface on one side and the planar base surface on a second, opposing side; and adhering the cutting table to the support surface of the substrate and the plurality of protrusions using an adhesive, the adhesive at least partially filling the voids between the support surface of the substrate and the planar base surface of the cutting table.
2. The method of claim 1, further comprising forming the intermediate structure from a material exhibiting a hardness greater than a hardness of a material forming the substrate.
3. The method of claim 1, wherein forming an intermediate structure comprises: forming the substrate and the plurality of protrusions from a powder mixture; and pressing and sintering the powder mixture to form a unitary sintered structure comprising the substrate and the plurality of protrusions.
4. The method of claim 1, further comprising forming a TSP cutting table by at least partially leaching a catalyst from the cutting table.
5. The method of claim 1, wherein adhering the cutting table comprises adhering the cutting table to the substrate and the plurality of protrusions using a brazing process.
6. The method of claim 1, wherein adhering the cutting table comprises flowing a brazing material into the voids defined by the plurality of protrusions and extending between the cutting table and the substrate.
7. The method of claim 1, wherein forming an intermediate structure comprises locating at least one of diamond grit, particles of cubic boron nitride, and particles of silicon carbide on the support surface of the substrate.
8. The method of claim 7, wherein locating at least one of diamond grit, particles of cubic boron nitride, and particles of silicon carbide on the support surface of the substrate comprises selecting the at least one of diamond grit, particles of cubic boron nitride, and particles of silicon carbide to have a uniform average particle size of between 10 microns and 100 microns.
9. The method of claim 1, further comprising extending each protrusion of the plurality of protrusions from the support surface of the substrate to a base surface of the cutting table.
10. The method of claim 9, further comprising contacting the base surface of the cutting table with each protrusion of the plurality of protrusions.
11. The method of claim 1, further comprising: selecting the substrate to comprises tungsten carbide; and forming the plurality of protrusions from a material relatively harder than the tungsten carbide of the substrate.
12. A method for fabricating a cutting element for use with an earth-boring tool, the method comprising: forming an intermediate structure comprising a plurality of particles secured to and protruding from a support surface of a substrate, the plurality of particles being separate from the substrate prior to the forming of the intermediate structure; and adhering a cutting table comprising a superabrasive material to the support surface of the substrate and the plurality of particles using an adhesive.
13. The method of claim 12, further comprising: selecting the cutting table to have a cutting surface on one side and a planar base surface on a second, opposing side; and positioning the planar base surface of the cutting table over the support surface proximate the plurality of particles.
14. The method of claim 12, further comprising adhering the plurality of particles to the support surface of the substrate.
15. The method of claim 12, further comprising forming the plurality of particles from at least one of diamond grit, carbide particles, nitride particles, oxide particles, and boride particles.
16. The method of claim 12, further comprising forming the plurality of particles with a plurality of carbide particles comprising at least one of tungsten carbide, cubic boron nitride, and silicon carbide.
17. The method of claim 12, further comprising selecting the plurality of particles to comprise a uniform particle size in a size range between 0.1 micron and 40 microns.
18. A method for fabricating a cutting element for use with an earth-boring tool, the method comprising: forming a plurality of protrusions comprising a first material on and protruding from a support surface of a substrate comprising a second material; selecting the first material of the plurality of protrusions to exhibit a hardness greater than a hardness of the second material of the substrate; and adhering a cutting table comprising a superabrasive material to the support surface of the substrate and the plurality of protrusions using an adhesive.
19. A method of forming an earth-boring tool, the method comprising: providing a tool body; and coupling at least one cutting element formed by the method recited in claim 1 to the tool body.
20. A method of forming an earth-boring tool, the method comprising: providing a tool body; and coupling at least one cutting element formed by the method recited in claim 12 to the tool body.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) While the specification concludes with claims particularly pointing out and distinctly claiming which are regarded as embodiments of the present disclosure, the advantages of embodiments of the disclosure may be more readily ascertained from the following description of embodiments of the disclosure when read in conjunction with the accompanying drawings in which:
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DETAILED DESCRIPTION
(9) The illustrations presented herein are not meant to be actual views of any particular material, apparatus, system, or method, but are merely idealized representations which are employed to describe the present disclosure. Additionally, elements common between figures may retain the same numerical designation.
(10) Embodiments of the present disclosure include cutting elements for use with earth-boring tools such as, for example, an earth-boring rotary drill bit.
(11) The bit body 12 may include internal fluid passageways (not shown) that extend between the face 13 of the bit body 12 and a longitudinal bore (not shown), which extends through the shank 14, the extension 18, and partially through the bit body 12. Nozzle inserts 24 also may be provided at the face 13 of the bit body 12 within the internal fluid passageways. The bit body 12 may further include a plurality of blades 26 that are separated by junk slots 28. In some embodiments, the bit body 12 may include gage wear plugs 32 and wear knots 38. One or more cutting elements 100 in accordance with embodiments of the present disclosure may be mounted on the face 13 of the bit body 12 in cutting element pockets 22 that are located along each of the blades 26. The bit body 12 of the earth-boring rotary drill bit 10 shown in
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(13) In some embodiments, the cutting table 102 may comprise a thermally stable PDC, or TSP. For example, a catalyst material used to form the PDC may be substantially removed (e.g., by leaching, electrolytic processes, etc.) from the polycrystalline diamond material in the cutting table 102. Removal of the catalyst material from the cutting table 102 may be controlled to substantially uniformly remove the catalyst material from the polycrystalline diamond material in the cutting table 102. The catalyst material within the polycrystalline diamond material in the cutting table 102 may be substantially removed from interstitial spaces within the polycrystalline material and from surfaces of the bonded diamond particles of which the polycrystalline material is comprised. After the removal process, the polycrystalline material in the cutting table 102 may have a portion (e.g., a substantial portion), or even the entirety of the polycrystalline diamond material, which is rendered substantially free of catalyst material.
(14) The substrate 104 may include a support surface 106 and a base portion 107. The base portion 107 of the substrate 104 may be attached (e.g., brazed) to an earth-boring tool (e.g., the earth-boring rotary drill bit 10 (
(15) The cutting element 100 may include an intermediate structure positioned between the substrate 104 and the cutting table 102. For example, a portion of the cutting element 100 (e.g., the substrate 104) may include a plurality of discrete protrusions 110 extending from the support surface 106 of the substrate 104. In some embodiments, the intermediate structure may be attached, prior to mutual securement thereof, to one of or both the cutting table 102 and the substrate 104. As shown in
(16) Referring still to
(17) In some embodiments, while the protrusions 110 may exhibit an exposure above support surface 106, the protrusions 110 may exhibit different heights, extending from the support surface 106 of the substrate 104. For example, the support surface 106 of the substrate 104 may exhibit a contoured surface (e.g., a convex surface, a concave surface, a surface formed by concentric rings, combinations thereof, or any other suitable non-planar surface geometry). In such an embodiment, the protrusions 110 at relatively higher portions of the support surface 106 of the substrate 104 may have a height smaller than a height of the protrusions 110 at relatively lower portions of the support surface 106 of the substrate 104. For example, in a concave surface, the protrusions 110 proximate to the edge of the substrate 104 will exhibit a height less than the protrusions 110 proximate to the center of the substrate 104.
(18) In some embodiments and as shown in
(19) In other embodiments and as shown in
(20) In some embodiments, the distance between the distal end of the protrusions 110 formed on the substrate 104 and the base surface 108 of the cutting table 102 may exhibit a distance substantially (e.g., by an order of magnitude or more) smaller than the distance between the support surface 106 of the substrate 104 and the base surface 108 of the cutting table 102.
(21) In some embodiments, an intermediate portion of the cutting element 100 (e.g., dimensions of the protrusions 110 and adhesion layer 114) may be sized to provide a cutting element 100 that exhibits relatively enhanced stiffness and toughness as compared to conventional cutting elements. For example, a distance between the distal end of the protrusions 110 and the base surface 108 of the cutting table 102 (e.g., a distance forming a void 113 between the distal end of the protrusions 110 and the base surface 108 of the cutting table 102 for a portion of the adhesion layer 114) may exhibit a distance of about 10 microns to 100 microns and a distance of exposure of the protrusions 110 may exhibit a distance of about 25 microns to 250 microns. Such a configuration may provide a cutting element 100 having an adhesion layer 114 enabling the cutting element 100 to absorb energy and deform without substantial fracturing (i.e., toughness) while the protrusions 110 will support the cutting table 102 by limiting the amount of deflection of the cutting table 102 (i.e., stiffness).
(22) Referring back to
(23) In some embodiments, portions of the cutting element 100 (e.g., the substrate 104 or, in some embodiments, the substrate 104 and the protrusions 110) may be fabricated using powder metallurgical processes such as, for example, press and sintering processes, directed powder spraying, and laser sintering. For example, portions of the cutting elements 100 may be fabricated using powder compaction and sintering techniques such as, for example, those disclosed in pending U.S. patent application Ser. No. 11/271,153, now U.S. Pat. No. 7,802,495, issued Sep. 28, 2010, and pending U.S. patent application Ser. No. 11/272,439, now U.S. Pat. No. 7,776,256, issued Aug. 17, 2010, each of which is assigned to the assignee of the present disclosure, and the entire disclosure of each of which is incorporated herein by this reference. Broadly, the methods comprise injecting a powder mixture into a cavity within a mold to form a green body, and the green body then may be sintered to a desired final density to form the portions of the cutting elements 100. Such processes are often referred to in the art as metal injection molding (MIM) or powder injection molding (PIM) processes. The powder mixture may be mechanically injected into the mold cavity using, for example, an injection molding process or a transfer molding process. To form a powder mixture for use in embodiments of methods of the present disclosure, a plurality of hard particles may be mixed with a plurality of matrix particles that comprise a metal matrix material. In some embodiments, an organic material also may be included in the powder mixture. The organic material may comprise a material that acts as a lubricant to aid in particle compaction during a molding process.
(24) The hard particles of the powder mixture may comprise diamond, or may comprise ceramic materials such as carbides, nitrides, oxides, and borides (including boron carbide (B.sub.4C)). More specifically, the hard particles may comprise carbides and borides made from elements such as W, Ti, Mo, Nb, V, Hf, Ta, Cr, Zr, Al, and Si. By way of example and not limitation, materials that may be used to form hard particles include tungsten carbide (WC), titanium carbide (TiC), tantalum carbide (TaC), titanium diboride (TiB.sub.2), chromium carbide (Cr.sub.3C.sub.2), titanium nitride (TiN), aluminum oxide (Al.sub.2O.sub.3), aluminum nitride (AlN), boron nitride (BN), silicon nitride (Si.sub.3N.sub.4), and silicon carbide (SiC). Furthermore, combinations of different hard particles may be used to tailor the physical properties and characteristics of the particle-matrix composite material.
(25) The matrix particles of the powder mixture may comprise, for example, cobalt-based, iron-based, nickel-based, aluminum-based, copper-based, magnesium-based, and titanium-based alloys. The matrix material may also be selected from commercially pure elements such as cobalt, aluminum, copper, magnesium, titanium, iron, and nickel. By way of example and not limitation, the matrix material may include carbon steel, alloy steel, stainless steel, tool steel, Hadfield manganese steel, nickel or cobalt superalloy material, and low thermal expansion iron- or nickel-based alloys such as INVAR. As used herein, the term superalloy refers to iron-, nickel-, and cobalt-based alloys having at least 12% chromium by weight. Additional example alloys that may be used as matrix material include austenitic steels, nickel-based superalloys such as INCONEL 625M or RENE 95, and INVAR type alloys having a coefficient of thermal expansion that closely matches that of the hard particles used in the particular particle-matrix composite material. More closely matching the coefficient of thermal expansion of matrix material with that of the hard particles offers advantages such as reducing problems associated with residual stresses and thermal fatigue. Another example of a matrix material is a Hadfield austenitic manganese steel (Fe with approximately 12% Mn by weight and 1.1% C by weight).
(26) In some embodiments, the portions of the cutting element 100 in contact with the adhesion layer 114 (e.g., the support surface 106 of the substrate 104 and, in some embodiments, the protrusions 110 formed on the support surface 106 of the substrate 104) may be processed to enhance subsequent adhesion of a preformed cutting table 102 thereto. Such processing of the portions of the cutting element 100 may, in some embodiments, include removal of one or more contaminants or materials that may weaken or otherwise interfere with optimal bonding of cutting table 102 to the portions of the cutting element 100.
(27) In other embodiments, the surface area of portions of the cutting element 100 in contact with the adhesion layer 114 (e.g., the support surface 106 of the substrate 104 and, in some embodiments, the protrusions 110 formed on the support surface 106 of the substrate 104) may be increased. For example, chemical, electrical, and/or mechanical processes may be used to increase the surface area of the portions of the cutting element 100 by removing material from the portions of the cutting element 100. For example, techniques for increasing the surface area of the portions of the cutting element 100 include laser ablation, blasting with abrasive material, and exposure to chemical etchants.
(28) In some embodiments, where the protrusions 110 are integrally formed from the substrate 104, the protrusions 110 on the support surface 106 of the substrate 104 may be formed by chemical, electrical, and/or mechanical processes used to increase the surface area of the portions of the cutting element 100 (e.g., as discussed above) by removing material from the portions of the cutting element 100. For example, the protrusions 110 may be formed by texturing or dimpling the support surface 106 of the substrate 104. By way of further example, techniques for foaming the protrusions 110 on the support surface 106 of the substrate 104 include machining (e.g., milling, electric discharge machining (EDM), grinding, etc.), laser ablation, blasting with abrasive material, and exposure to chemical etchants.
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(30) Although embodiments of methods of the present disclosure have been described hereinabove with reference to cutting elements for earth-boring rotary drill bits, the present disclosure may be used to form cutting elements for use with earth-boring tools and components thereof other than fixed-cutter rotary drill bits including, for example, other components of fixed-cutter rotary drill bits, roller cone bits, hybrid bits incorporating fixed cutters and rolling cutting structures, core bits, eccentric bits, bicenter bits, reamers, mills, and other such tools and structures known in the art. Accordingly, the term earth-boring tool encompasses all of the foregoing tools and structures.
(31) Embodiments of the present disclosure may be particularly useful in forming cutting elements for earth-boring tools that provide improved structural support between the cutting tables and the substrates of cutting elements. For example, such configurations may provide cutting elements where an intermediate structure supplies additional support under bending and tensile stresses to a cutting table, which may reduce the tendency of failure of the cutting element under such stresses during drilling operations as compared to other conventional cutting elements. As discussed above, configurations of the adhesion layer between the cutting table and substrate of a conventional cutting element may introduce stresses to the cutting table and the interface between the cutting table and the substrate due to a relatively softer adhesion layer allowing the cutting table to flex and deform during drilling operations. Such flexure and deformation may cause the cutting element to fail during drilling operations due to failure of the cutting table or failure of the interface between the cutting table and the substrate. Conventional cutting elements including TSP cutting tables may particularly exhibit problems related to the bonding of the substrate to the TSP cutting table. Cutting elements in accordance with embodiments of the present disclosure may provide a cutting element providing greater support and stiffness for the cutting table mounted on a substrate with an intermediate structure and an adhesion layer disposed therebetween. Such configurations may be relatively less susceptible to failure of the cutting elements due to failure of the cutting table or failure of the interface between the cutting table and the substrate. The intermediate structure may also provide additional surface area over which the adhesion layer is applied in order to strengthen the bond between the cutting table and the substrate.
(32) While the present disclosure has been described herein with respect to certain embodiments, those of ordinary skill in the art will recognize and appreciate that it is not so limited. Rather, many additions, deletions and modifications to the described embodiments may be made without departing from the scope of the disclosure as hereinafter claimed, including legal equivalents. In addition, features from one embodiment may be combined with features of another embodiment while still being encompassed within the scope of the disclosure as contemplated by the inventors.