WO2016109110A1

WO2016109110A1 - Cutting elements and drill bits incorporating the same

Info

Publication number: WO2016109110A1
Application number: PCT/US2015/063646
Authority: WO
Inventors: Lynn Belnap; Stewart Middlemiss
Original assignee: Smith International, Inc.
Priority date: 2014-12-31
Filing date: 2015-12-03
Publication date: 2016-07-07

Abstract

A drill bit for use with a drilling tool, such as a handheld rotary hammer tool. The drill bit includes a shank and an ultra-hard cutting element coupled to the shank. At least a portion of an outer surface of the ultra-hard cutting element includes an ultra-hard abrasive material. The ultra-hard cutting element includes at least one flute. The ultra-hard abrasive material may be polycrystalline diamond or polycrystalline cubic boron nitride. The drill bit may also include one or more lips extending radially across at least a portion of the outer surface.

Description

CUTTING ELEMENTS AND DRILL BITS INCORPORATING THE SAME

CROSS REFERENCE

[0001] This application claims the benefit of U.S. Provisional Application No. 62/098,566, entitled "CUTTING ELEMENTS AND DRILL BITS FNCORPORATING THE SAME," filed December 31, 2014, the disclosure of which is hereby incorporated herein by reference.

BACKGROUND

[0002] Rotary hammer tools are used in a variety of industries, such as, for instance, in the construction industry to install wall anchors for hanging struts or for forming electrical conduits in a structure (e.g., a cement structure, a masonry structure, or a rock formation). In operation, a drill bit coupled to the rotary hammer tool is repeatedly axially reciprocated and rotated to advance the drill bit further into the structure. The axial reciprocation (i.e., hammering) of the drill bit is configured to crush or crack the structure and the rotary action of the drill bit is configured to cut into the structure.

[0003] Conventional drill bits for use in rotary hammer tools include a carbide insert on a tip of the drill bit. For instance, conventional drill bits may include a carbide wafer brazed into a slot in the tip of the drill bit. Other conventional drill bits may include a solid carbide tip brazed or welded to a shank of the drill bit.

[0004] However, carbide inserts tend to wear after prolonged use. As the carbide inserts wear, the efficiency of the rotary hammer tool decreases. For instance, the wearing of the carbide insert reduces the efficiency of the hammering action of the drill bit to crush or crack the structure. Additionally, as the carbide inserts wear, sharp edges of the carbide inserts round, which reduces the efficiency of the rotary action of the drill bit to cut into the structure. Additionally, as the carbide insert on a conventional drill bit wears, the rate of penetration of the drill bit into the structure decreases. Accordingly, the drilling rate of conventional drill bits is inconsistent over the service life of the drill bit due to the wearing of the carbide tip.

SUMMARY

[0005] The present disclosure is directed to various embodiments of drill bits. In one embodiment, the drill bit includes a shank and an ultra-hard cutting element coupled to the shank. At least a portion of an outer surface of the ultra-hard cutting element includes an ultra-hard abrasive material. At least one flute is defined in the ultra-hard cutting element. The ultra-hard abrasive material may be polycrystallme diamond or polycrystallme cubic boron nitride. At least a portion of the ultra-hard abrasive material may have a hardness of at least approximately 4000 kg/mm². The outer surface of the ultra-hard cutting element may have any suitable shape, such as substantially spherical. The drill bit may also include at least one angled notch extending from the outer surface of the ultra-hard cutting element to an outer end of the flute. The ultra-hard cutting element may include a lip extending radially across at least a portion of the outer surface. The shank may be a cylindrical member having a plurality of helical flutes and the ultra-hard cutting element may have a plurality of flutes. Each of the flutes in the ultra-hard cutting element may be aligned with one of the helical flutes in the shank. The flutes in the ultra-hard cutting element may be helical or axial.

[0006] The present disclosure is also directed to various embodiments of ultra-hard cutting elements. In one embodiment, the ultra-hard cutting element includes a base portion defining a longitudinal axis, an extension portion on an end of the base portion, and a lip on the outer surface of the extension portion. The lip has a length between a first end and a second end. At least a portion of an outer surface of the extension portion includes an ultra-hard abrasive material. The ultra-hard abrasive material may be polycrystallme diamond or polycrystallme cubic boron nitride. The outer surface of the ultra-hard cutting element may have any suitable shape, such as substantially spherical. The lip may extend radially across at least a portion of the outer surface. A height of the lip may taper between a higher end proximate the longitudinal axis and a lower end proximate an interface edge between the outer surface and a sidewall of the base portion. The height of the lip may be substantially constant along the length of the lip. The lip may be defined by a depression in the outer surface of the extension portion. The lip may project beyond the outer surface of the extension portion. The ultra-hard cutting element may include a first lip extending radially across the outer surface in a first direction and a second lip extending radially across the outer surface in a second direction different than the first direction. The second direction may be opposite the first direction. The first and second lips may each include a cutting face, and the cutting face of the first lip may face in a direction opposite the cutting face of the second lip.

[0007] The present disclosure is also directed to various methods of manufacturing a drill bit. In one embodiment, the method includes coupling an ultra-hard cutting element to a shank. An outer surface of the ultra-hard cutting element includes an ultra-hard abrasive material. The ultra-hard abrasive material polycrystalline diamond or polycrystalline cubic boron nitride. Coupling the ultra- hard cutting element to the shank may include brazing and/or welding the ultra-hard cutting element to the shank. The method may also include forming the ultra-hard cutting element before the coupling of the ultra-hard cutting element to the shank. Forming the ultra-hard cutting element may include high pressure, high temperature sintering a mixture of diamond particles or cubic boron nitride particles and a catalyst material or a ceramic binder to a substrate. Forming the ultra-hard cutting element may include forming a lip extending radially across at least a portion of the outer surface. Forming the lip may include inserting the mixture in a deformable can and deforming at least a portion of the diamond particles and the deformable can with a forming device. The method may also include forming a series of flutes in the ultra-hard cutting element. Forming the flutes may include electrical discharge machining the flutes.

[0008] 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] These and other features and advantages of embodiments of the present disclosure will become more apparent by reference to the following detailed description when considered in conjunction with the following drawings. In the drawings, like reference numerals are used throughout the figures to reference like features and components. The figures are not necessarily drawn to scale.

[0010] FIG. 1 is a perspective view of a drill bit according to one embodiment of the present disclosure;

[0011 ] FIGS . 2 A and 2B are a perspective view and a side view, respectively, of a cutting element according to one embodiment of the present disclosure;

[0012] FIGS. 3A and 3B are a perspective view and a side view, respectively, of a cutting element according to another embodiment of the present disclosure;

[0013] FIGS . 4A and 4B are a perspective view and a side view, respectively, of a cutting element according to a further embodiment of the present disclosure;

[0014] FIG. 5 is a flowchart illustrating tasks of forming a drill bit according to one embodiment of the present disclosure; and

[0015] FIG. 6 is a schematic view of an assembly used to manufacture a drill bit according to one embodiment of the present disclosure.

DETAILED DESCRIPTION

[0016] The present disclosure is directed to various embodiments of a drill bit having an ultra- hard cutting element. The drill bits of the present disclosure may be used in any suitable type of tool, such as, for instance, a handheld rotary hammer tool for drilling a hole into a structure (e.g., a cement structure, a masonry structure, or a rock formation). The ultra-hard cutting elements of the present disclosure include wear-resistant properties configured to prolong the service life of the drill bit and provide a generally consistent drilling rate by reducing the wear of the drill bit. Embodiments of the cutting elements of the present disclosure may also include one or more geometric features configured to concentrate the force of the hammering action of the drill bit onto a localized area of the structure. Embodiments of the cutting elements of the present disclosure may also include one or more geometric features configured to cut into the structure during the rotary action of the drill bit.

[0017] With reference now to FIG. 1 , a drill bit 100 according to one embodiment of the present disclosure includes a shank 101 and an ultra-hard cutting element 102 coupled to the shank 101. The ultra-hard cutting element 102 defines a tip 103 of the drill bit 100 that engages a structure (e.g., a cement structure, a masonry structure, or a rock formation) during a drilling operation. The drill bit 100 of the present disclosure may be any type of drill bit suitable for the composition of the structure the drill bit 100 is intended to drill through, the type of tool with which the drill bit 100 is intended to be used, and/or the type of hole desired to be drilled in the structure, such as, for instance, a masonry drill bit or a reamer drill bit. In the illustrated embodiment, the shank 101 is a generally cylindrical member having a proximal tool-engaging end 104 and a distal end 105 opposite the proximal end 104. The distal end 105 of the shank 101 may be coupled to the ultra-hard cutting element 102 by any suitable process, such as, for instance, brazing or welding. The proximal tool- engaging end 104 of the shank 101 may include one or more circumferentially disposed flats or notches 106 configured to be engaged by a tool (e.g., a chuck on a handheld rotary hammer tool). Additionally, in the illustrated embodiment, the shank 101 defines a plurality of helical flutes 107 extending along at least a portion of a length of the shank 101 from the distal end 105 toward the proximal end 104. The helical flutes 107 are configured to direct formation cuttings away from the tip 103 of the drill bit 100 during a drilling operation. The shank 101 may be made out of any suitably strong and durable material, such as, for instance, steel or tungsten carbide.

[0018] With reference now to FIGS. 2A and 2B, the ultra-hard cutting element 102 in the illustrated embodiment includes a base portion 108 and an extension portion 109 coupled to or integrally formed with the base portion 108. In the illustrated embodiment, the base portion 108 is cylindrical and includes a circular base 110 and a cylindrical sidewall 111 extending from the circular base 110. In one or more embodiments, the base portion 108 of the ultra-hard cutting element 102 may have any other suitable shape depending, for instance, on the composition of the structure the drill bit 100 is intended to drill through and the type of tool with which the drill bit 100 is intended to be used. A longitudinal axis A extends through the base portion 108. The cylindrical sidewall 111 of the base portion 108 may have any suitable length L along the longitudinal axis A.

[0019] The extension portion 109 of the ultra-hard cutting element 102 includes an outer formation-engaging surface 113. The ultra-hard cutting element 102 also includes a circumferential edge 114 at the interface between the extension portion 109 and the cylindrical sidewall 111 of the base portion 108. In the illustrated embodiment, the outer formation-engaging surface 113 of the extension portion 109 is spherical or substantially spherical. The extension portion 109 also defines an apex or a crown 115 on the outer surface 113 that is furthest from the circular base 110 of the base portion 108. The extension portion 109 has a maximum height H defined between the apex 115 and a plane that is perpendicular to the longitudinal axis A and extends through the circumferential edge 114. The outer formation-engaging surface 113 of the extension portion 109 also has a radius of curvature R. Although in the illustrated embodiment the radius of curvature R of the outer formation- engaging surface 113 is constant or substantially constant, in one or more alternate embodiments, the radius of curvature R may vary across the outer formation-engaging surface 113. In one embodiment, the outer surface of the extension portion 109 may be a spherical cap or a spherical dome the maximum height H of which is less than the radius of curvature R of the spherical cap. In one or more embodiments, the outer formation- engaging surface 113 may hemispherical (i.e., the height H of the outer formation-engaging surface 113 of the extension portion 109 may be equal or substantially equal to the radius R of the outer formation-engaging surface 113). In one or more embodiments, the outer formation-engaging surface 113 of the extension portion 109 may have any other suitable shape, such as, for instance, conical, frusto-conical, ellipsoidal, or substantially ellipsoidal. Additionally, in one or more embodiments, at least a portion of the outer formation- engaging surface 113 may include a flat or substantially flat segment or portion (e.g., the outer formation-engaging surface 113 may include a straight segment and a curved segment).

[0020] At least a portion of the outer formation-engaging surface 113 may be formed from any material having highly abrasive and/or wear-resistant properties. In one embodiment, at least a portion of the outer formation-engaging surface 113 may include polycrystalline diamond ("PCD") or polycrystalline cubic boron nitride ("PCBN"). In one embodiment, the outer formation-engaging surface 113 of the ultra-hard cutting element 102 may include any suitable type of thermally stable polycrystalline diamond (e.g., leached PCD, non-metal catalyst PCD, or catalyst-free PCD) or thermally stable PCBN. In one embodiment, the material of at least a portion of the outer formation- engaging surface 113 of the ultra-hard cutting element 102 may have a hardness greater than or equal to approximately 4000 kg/mm². Although in one embodiment only the outer formation-engaging surface 113 (or a portion thereof) of the extension portion 109 is formed from PCD or PCBN, in one or more embodiments, any other suitable portion of the extension portion 109 may be formed from PCD or PCBN. For instance, in one embodiment, all or substantially all of the extension portion 109 may be formed from PCD or PCBN.

[0021] In one embodiment, a remainder of the ultra-hard cutting element 102 may be formed from any suitably hard and durable material, such as, for instance, tungsten carbide or other matrix materials of carbides, nitrides, and/or borides (e.g., in one embodiment, the base portion 108 and the portion of the extension portion 109 below the outer formation-engaging surface 113 may be formed from tungsten carbide). In one embodiment, the material of the remainder of the ultra-hard cutting element 102 may be selected to facilitate coupling (e.g., by welding or brazing) the ultra-hard cutting element 102 to the shank 101 during a process of manufacturing the drill bit 100, as described in more detail below. Additionally, in one embodiment, the material of the remainder of the ultra-hard cutting element 102 may be infiltrated into interstitial spaces (e.g., pores or voids) defined between a network of interconnected crystals of the PCD or PCBN outer formation-engaging surface 113. [0022] In one embodiment, the ultra-hard cutting element 102 may include one or more transition layers (e.g., a diamond-tungsten carbide composite material). For instance, in one embodiment, the ultra-hard cutting element 102 may include a transition layer between the PCD or PCBN outer formation-engaging surface 113 and an inner portion of the ultra-hard cutting element 102 formed from tungsten carbide. The material of the transition layer may be selected such that the transition layer has a coefficient of thermal expansion that is between a coefficient of thermal expansion of the PCD or PCBN outer formation-engaging surface 113 and a coefficient of thermal expansion of tungsten carbide of the inner portion of the ultra-hard cutting element 102. In one embodiment, the material of the transition layer may also be selected such that the transition layer has an elastic modulus that is between the elastic modulus of the PCD or PCBN outer formation-engaging surface 113 and the elastic modulus of the tungsten carbide of the inner portion of the ultra-hard cutting element 102. In one embodiment, a portion of the transition layer may be infiltrated into the interstitial spaces defined between the network of interconnected crystals of the PCD or PCBN outer formation-engaging surface 113 (e.g., cobalt from the transition layer may be infiltrated into the PCD or PCBN on the outer formation-engaging surface 113). Accordingly, in one embodiment, the transition layer may be configured to mitigate the formation of thermal stress concentrations which might otherwise develop when the ultra-hard cutting element 102 is subject to elevated temperatures, such as during a drilling operation, due to the thermal expansion differential between the PCD or PCBN layer and the tungsten carbide (i.e., the one or more transition layers may be configured to mitigate the formation of thermal cracks in the outer formation-engage surface 113 due to the thermal expansion differential between the PCD or PCBN outer formation-engaging surface 113 and the inner tungsten carbide, which may result in the premature failure of the ultra-hard cutting element 102). The transition layer may also serve to reduce the elastic mismatch between the PCD or PCBN outer formation-engaging surface 113 and the tungsten carbide of the inner portion of the ultra-hard cutting element 102, thereby improving reliability of the ultra-hard cutting element 102, particularly during dynamic loading of the ultra-hard cutting element 102. [0023] Still referring to the embodiment illustrated in FIGS. 2A and 2B, the ultra-hard cutting element 102 also defines a plurality of flutes 116. The flutes 116 in the ultra-hard cutting element 102 are configured to cooperate with the flutes 107 in the shank 101 (see FIG. 1) to direct formation cuttings away from the tip 103 of the drill bit 100 during a drilling operation. In the illustrated embodiment, the ultra-hard cutting element 102 defines a pair of diametrically opposed flutes 116 (i.e., the pair of flutes 116 are angularly spaced apart along the circumferential interface edge 114 by angle a of approximately 180°). In the illustrated embodiment, the flutes 116 in the ultra-hard cutting element 102 are aligned with the flutes 107 defined in the shank 101. In one or more embodiments, the ultra-hard cutting element 102 may define any other suitable number of flutes 116 corresponding to the number of flutes 107 in the shank 101. Additionally, the flutes 116 in the ultra-hard cutting element 102 may be spaced apart by any other suitable angle a depending on the arrangement of the flutes 107 defined in the shank 101. In one or more embodiments, the number and/or orientation of flutes 116 in the ultra-hard cutting element 102 may not correspond to the number and/or orientation of the flutes 107 in the shank 101.

[0024] Furthermore, in the illustrated embodiment, the plurality of flutes 116 defined by the ultra-hard cutting element 102 extend axially along the cylindrical sidewall 111 of the base portion 108 (e.g., the flutes 116 extend parallel or substantially parallel to the longitudinal axis A). The flutes 116 extend between the outer formation-engaging surface 113 and the circular base 110 of the base portion 108. In one or more embodiment, the flutes 116 may have any other suitable orientation. For instance, in one embodiment, the flutes 116 may be curved (e.g., the flutes 116 may extend helically around the longitudinal axis A). Additionally, in the illustrated embodiment, the flutes 116 are wedge-shaped in a plane perpendicular to the longitudinal axis A (e.g., the flutes 116 taper between a wider end 117 proximate the cylindrical sidewall 111 and a narrower end 118 proximate the longitudinal axis A). In one or more alternate embodiments, the flutes 116 may have any other suitable cross-sectional shape, such as, for instance, a curved cross-sectional shape (e.g., a semicircular cross-section). [0025] Additionally, in the embodiment illustrated in FIGS. 2A and 2B, ultra-hard cutting element 102 also defines a pair of angled notches 119. The notches 119 extend from the outer formation-engaging surface 113, into the extension portion 109 of the ultra-hard cutting element 102, and to outer ends of the flutes 116. In the illustrated embodiment, sharp edges 120 are defined at interfaces between the angled notches 119 and the outer formation-engaging surface 113. The sharp edges 120 are configured to facilitate cutting into a structure. For instance, when the drill bit 100 is attached to a handheld rotary hammer tool, the sharp edges 120 are configured to cut into the structure due to the rotary action of the drill bit 100. The notches 120 may by angled at any suitable angle β relative to a plane extending through the longitudinal axis A, such as, for instance, from approximately 10 degrees to approximately 60 degrees. In one embodiment, the angle β of the notches 119 may be greater than 60 degrees. Although in the illustrated embodiment the ultra-hard cutting element 102 defines two notches 119, in one or more embodiments, the ultra-hard cutting element 102 may define any other suitable number of notches 119, such as, for instance, more or fewer than two notches 119. Additionally, although in the illustrated embodiment the number of notches 119 corresponds to the number of flutes 116, in one or more embodiment, the number of notches 119 may differ from the number of flutes 116.

[0026] With reference now to FIGS. 3 A and 3B, an ultra-hard cutting element 200 according to another embodiment of the present disclosure includes a base portion 201 and an extension portion 202 coupled to or integrally formed with the base portion 201. In the illustrated embodiment, the base portion 201 is cylindrical and includes a circular base 203 and a cylindrical sidewall 204 extending from the circular base 203, although in one or more embodiments, the base portion 201 may have any other suitable shape. The base portion 201 also defines a longitudinal axis A'. The cylindrical sidewall 204 of the base portion 201 may have any suitable diameter D and may have any suitable length L' along the longitudinal axis A'.

[0027] In the illustrated embodiment, an outer formation-engaging surface 205 of the extension portion 202 is substantially spherical. For instance, in one embodiment, the outer formation-engaging surface 205 of the extension portion 202 may be a substantially spherical cap or a substantially spherical dome. In another embodiment, the outer formation-engaging surface 205 of the extension portion 202 may be substantially hemispherical. In one or more embodiments, the outer formation- engaging surface 205 of the extension portion 202 may have any other suitable shape, such as, for instance, conical, frusto-conical, ellipsoidal, or substantially ellipsoidal. Additionally, in one or more embodiments, at least a portion of the outer formation-engaging surface 205 may include a flat or substantially flat segment or portion (e.g., the outer formation-engaging surface 205 may include a straight segment and a curved segment). A center 206 of the outer formation-engaging surface 205 is defined at the intersection between the longitudinal axis A' and the outer formation-engaging surface 205. The ultra-hard cutting element 200 also includes a circumferential edge 207 at the interface between the outer formation-engaging surface 205 and the cylindrical sidewall 204 of the base portion 201. The extension portion 202 has a height H' defined between the center 206 and a plane that is perpendicular to the longitudinal axis A' and extends through the circumferential edge 207. The outer formation-engaging surface 205 of the extension portion 202 also has a radius of curvature R\ In one embodiment, at least a portion of the outer formation-engaging surface 205 may be formed from any material having highly abrasive and/or wear-resistant properties, such as, for instance, one or more of the materials of the outer formation-engaging surface 113 described above with reference to the embodiment of the ultra-hard cutting element 102 illustrated in FIGS. 2A and 2B (e.g., PCD, PCBN, and/or any material having a hardness greater than or equal to approximately 4000 kg/mm²). Although in one embodiment only the outer formation-engaging surface 205 (or a portion thereof) of the extension portion 202 is formed from PCD or PCBN, in one or more embodiments, any other suitable portion of the extension portion 202 may be formed from PCD or PCBN. For instance, in one embodiment, all or substantially all of the extension portion 202 may be formed from PCD or PCBN.

[0028] Still referring to the embodiment illustrated in FIGS. 3A and 3B, the outer formation- engaging surface 205 of the ultra-hard cutting element 200 also defines a pair of ridges or lips 208, 209. In the illustrated embodiment, the first lip 208 extends radially outward from the center 206 toward the circumferential interface edge 207 in a first direction and the second lip 209 extends radially outward from the center 206 toward the circumferential interface edge 207 in a second direction. In the illustrated embodiment, the first and second lips 208, 209 extend radially outward from the center 206 in opposite directions (i.e., the first and second lips 208, 209 are angularly spaced apart along the circumferential interface edge 207 by an angle μ of approximately 180°). In one or more alternate embodiments, the lips 208, 209 may be spaced apart by any other suitable angle μ. Although in the illustrated embodiment, the ultra-hard cutting element 200 includes two lips 208, 209, in one or more alternate embodiments, the ultra-hard cutting element 200 may include any other suitable number of lips 208, 209, such as, for instance, from one to eight lips. For instance, in one embodiment, the ultra-hard cutting element 200 may include four lips equally spaced apart by an angle μ of approximately 90°. Additionally, in one embodiment in which the ultra-hard cutting element 200 includes three or more lips, the lips may not be equally spaced apart. Furthermore, in the illustrated embodiment, the lips 208, 209 extend from the center 206 to the circumferential interface edge 207, although in one or more alternate embodiments, the lips 208, 209 may not extend completely to the circumferential interface edge 207 and/or may not extend completely to the center 206. Furthermore, although in the illustrated embodiment the lips 208, 209 are straight or substantially straight, in one or more embodiments, the lips 208, 209 may not be straight (e.g., the lips 208, 209 may be curved such that the lips 208, 209 are arranged in a spiral pattern). Additionally, although in the illustrated embodiment the lips 208, 209 together extend diametrically across the extension portion 202 such that the lips 208, 209 pass through the longitudinal axis A', in one or more alternate embodiments, one or more of the lips 208, 209 may be offset (i.e., spaced apart) from the longitudinal axis A' by any suitable distance. In an embodiment in which one or more of the lips 208, 209 are spaced apart from the longitudinal axis A', one or more of the outer ends of the lips 208, 209 may not be orthogonal to the circumferential interface edge 207 (e.g., one or more of the outer ends of the lips 208, 209 may be oriented at an acute angle relative to the circumferential interface edge 207).

[0029] In the illustrated embodiment, the lips 208, 209 segment or divide the outer formation- engaging surface 205 into a first portion 210 and a second portion 211. In one or more alternate embodiments, the outer formation-engaging surface 205 may be divided into any other number of portions depending on the number of lips 208, 209. In the illustrated embodiment, the lips 208, 209 are defined by recesses or depressions 212, 213 in the first and second portions 210, 211, respectively, of the outer formation-engaging surface 205. Accordingly, due to the presence of the first depression 212, the first portion 210 of the outer formation-engaging surface 205 slopes between a higher end 214 at the first lip 208 and a lower end 215 at the second lip 209. Due to the presence of the second depression 213, the second portion 211 of the outer formation-engaging surface 205 slopes between a higher end 216 at the second lip 209 and a lower end 217 at the first lip 208. Accordingly, the first lip 208 is defined between the higher end 214 of the first portion 210 and the lower end 217 of the second portion 211 of the outer formation-engaging surface 205. The second lip 209 is defined between the higher end 216 of the second portion 211 and the lower end 215 of the first portion 210 of the outer formation-engaging surface 205. Additionally, due to the depressions 212, 213, the radius of curvature R' varies across the first and second portions 210, 211 of the outer formation-engaging surface 205.

[0030] In one embodiment, the ultra-hard cutting element 200 may include one or more transition layers (e.g., a diamond-tungsten carbide composite material). For instance, in one embodiment, the ultra-hard cutting element 200 may include a transition layer between the PCD or PCBN outer formation-engaging surface 205 and the lips 208, 209 and an inner portion of the ultra-hard cutting element 200 formed from tungsten carbide. The material of the transition layer may be selected such that the transition layer has a coefficient of thermal expansion that is between a coefficient of thermal expansion of the PCD or PCBN outer formation-engaging surface 205 and the lips 208, 209 and a coefficient of thermal expansion of tungsten carbide of the inner portion of the ultra-hard cutting element 200. In one embodiment, the material of the transition layer may also be selected such that the transition layer has an elastic modulus that is between the elastic modulus of the PCD or PCBN outer formation-engaging surface 205 and the lips 208, 209 and the elastic modulus of the tungsten carbide of the inner portion of the ultra-hard cutting element 200. In one embodiment, a portion of the transition layer may be infiltrated into the interstitial spaces defined between the network of interconnected crystals of the PCD or PCBN outer formation-engaging surface 205 and/or the PCD or PCBN lips 208, 209 (e.g., cobalt from the transition layer may be infiltrated into the PCD or PCBN on the outer formation-engaging surface 205 and/or infiltrated into the PCD or PCBN on the lips

208, 209). Additionally, in one or more embodiments, the material properties of at least one of the first portion 210, the second portion 211, the first lip 208, and the second lip 209 may be different than the material properties of at least one of the other portions 210, 211 or one of the other lips 208,

209. For instance, in one embodiment, one of the first portion 210, the second portion 211, the first lip 208, or the second lip 209 may have a hardness less than one of the other portions 210, 211 or one of the other lips 208, 209 by approximately 500 kg/mm² to approximately 2500 kg/mm², such as, for instance, by approximately 2200 kg/mm².

[0031] In the illustrated embodiment, each lip 208, 209 includes a cutting face 218, 219 configured cut into a structure (e.g., a masonry or cement structure) when the ultra-hard cutting element 200 is rotated against the structure. In the illustrated embodiment, the faces 218, 219 of the lips 208, 209 are perpendicular or substantially perpendicular to the first and second portions 210, 211, respectively, of the outer formation-engaging surface 205. In one or more alternate embodiments, the faces 218, 219 of the lips 208, 209 may be canted at angles relative to planes perpendicular to the first and second portions 210, 211 of the outer formation-engaging surface 205. In the illustrated embodiment, the cutting face 218 of the first lip 208 is aligned with the cutting face 219 of the second lip 209, although in one or more alternate embodiments the cutting face 218 of the first lip 208 may not be aligned with the cutting face 219 of the second lip 209. Additionally, in the illustrated embodiment, outer ends 220, 221 of the cutting faces 218, 219 are rounded such that the lips 208, 209 blend into the first and second portions 210, 211, respectively, of the outer formation- engaging surface 205. In one or more alternate embodiments, the outer ends 220, 221 of the cutting faces 218, 219 may define sharp edges. In one or more alternate embodiments, one or more of the outer ends 220, 221 of the cutting faces 218, 219 may include a chamfer. Opposite sides of the chamfers may be either rounded (e.g., include a radius) or may define sharp edges. Additionally, in one embodiment, inner ends 222, 223 of the cutting faces 218, 219 may be rounded such that the lips 208, 209 blend into the second and first portions 211, 210, respectively, of the outer formation- engaging surface 205, although in one or more alternate embodiments, the inner ends 222, 223 of the lips 208, 209 may define sharp edges. Furthermore, in the illustrated embodiment, the cutting faces 218, 219 of the lips 208, 209 face in opposite directions. Accordingly, during a drilling operation (e.g., a rotary percussive drilling operation or a rotary drilling operation), both lips 208, 209 are configured to engage and cut into the structure (i.e., during a drilling operation, both of the opposing cutting faces 218, 219 of the lips 208, 209 are advanced into the structure).

[0032] A height h of the lips 208, 209 is defined between the inner ends 222, 223 and the outer ends 220, 221 of the cutting faces 218, 219, respectively. In the illustrated embodiment, the maximum height h of each of the lips 208, 209 is at an intermediate point between the center 206 and the circumferential interface edge 207. Additionally, in the illustrated embodiment, the height h of each of the lips 208, 209 tapers between the highest point and lower points proximate the center 206 (i.e., the intersection between the longitudinal axis A' and the outer formation-engaging surface 205) and the circumferential interface edge 207 where the outer formation-engaging surface 205 joins the sidewall 204 of the base portion 201. In one or more embodiments, the highest points of the lips 208, 209 may be proximate the center 206 (i.e., the intersection between the longitudinal axis A' and the outer formation-engaging surface 205) or any other suitable location, such as, for instance, proximate the circumferential interface edge 207. Additionally, in the illustrated embodiment, the height h of each of the lips 208, 209 at or proximate the circumferential interface edge 207 is zero or substantially zero. In one or more alternate embodiments, the height h of each of the lips 208, 209 may be constant or substantially constant along the length of each of the lips 208, 209. In one or more embodiments, the lips 208, 209 may include a segment or a portion that has a constant or substantially constant height and a segment that tapers between a higher end and a lower end. In one embodiment, the height h of the lips 208, 209 may not taper uniformly. The lips 208, 209 may have any suitable maximum height h depending, for instance, on the desired performance characteristics of the ultra- hard cutting element 200 and the composition of the material the ultra-hard cutting element 200 is intended to drill through. In one or more embodiments, the ratio of the maximum height h of the lips 208, 209 to the diameter D of the cylindrical sidewall 204 of the ultra-hard cutting element 200 may be from approximately 0.01 to approximately 0.4. In one or more embodiments, the ratio of the maximum height h of the lips 208, 209 to the diameter D of the cylindrical sidewall 204 of the ultra- hard cutting element 200 may be from approximately 0.01 to approximately 0.1. In one or more embodiments, the ratio of the maximum height h of the lips 208, 209 to the diameter D of the cylindrical sidewall 204 may be greater than 0.4. In another embodiment, the ratio of the maximum height h of the lips 208, 209 to the diameter D of the cylindrical sidewall 204 may be less than 0.01.

[0033] Still referring to the embodiment illustrated in FIGS. 3 A and 3B, the ultra-hard cutting element 200 also defines a plurality of flutes 224 extending between the first and second portions 210, 211, respectively, of the outer formation-engaging surface 205 and the circular base 203 of the base portion 201. Although in the illustrated embodiment the flutes 224 have a semicircular cross- sectional shape in a plane perpendicular to the longitudinal axis A', in one or more embodiments, the flutes 224 may have any other suitable cross-sectional shape, such as, for instance, a tapered cross- sectional shape (e.g., wedge-shaped). Additionally, although in the illustrated embodiment the flutes 224 extend axially along the cylindrical sidewall 204 of the base portion 201 (e.g., the flutes 224 extend parallel or substantially parallel to the longitudinal axis A'), in one or more embodiments, the flutes 224 may be curved (e.g., the flutes 224 may extend helically around the longitudinal axis A').

[0034] Additionally, in the illustrated embodiment, the lips 208, 209 on the outer formation- engaging surface 205 are tangential to the flutes 224 defined in the ultra-hard cutting element 200. In the illustrated embodiment, the lips 208, 209 intersect the circumferential interface edge 207 at the same point an edge 225 of the flutes 224 intersects the circumferential interface edge 207. Accordingly, in the illustrated the lips 208, 209 and the flutes 224 are positioned such that the lips 208, 209 are configured to direct the formation cuttings into the flutes 224 during a drilling operation. Accordingly, in the illustrated embodiment, the flutes 224 are angularly spaced apart by the same or substantially the same angle μ as the lips 208, 209. In one or more alternate embodiments, the lips 208, 209 may have any other suitable position on the outer formation-engage surface 205 relative to the flutes 224.

[0035] With reference now to FIGS. 4 A and 4B, an ultra-hard cutting element 300 according to another embodiment of the present disclosure includes a base portion 301 and an extension portion 302 coupled to or integrally formed with the base portion 301. In the illustrated embodiment, the base portion 301 is cylindrical and includes a circular base 303 and a cylindrical sidewall 304 extending from the circular base 303, although in one or more embodiments, the base portion 301 may have any other suitable shape. The base portion 301 also defines a longitudinal axis A". The cylindrical sidewall 304 of the base portion 301 may have any suitable diameter D' and may have any suitable length L" along the longitudinal axis A".

[0036] In the illustrated embodiment, an outer formation-engaging surface 305 of the extension portion 302 is substantially spherical. For instance, in one embodiment, the outer formation-engaging surface 305 of the extension portion 302 may be a substantially spherical cap or a substantially spherical dome. In another embodiment, the outer formation-engaging surface 305 of the extension portion 302 may be substantially hemispherical. In one or more embodiments, the outer formation- engaging surface 305 of the extension portion 302 may have any other suitable shape, such as, for instance, conical, frusto-conical, ellipsoidal, or substantially ellipsoidal. Additionally, in one or more embodiments, at least a portion of the outer formation-engaging surface 305 may include a fiat or substantially fiat segment or portion (e.g., the outer formation-engaging surface 305 may include a straight segment and a curved segment). A center 306 of the outer formation-engaging surface 305 is defined at the intersection between the longitudinal axis A" and the outer formation-engaging surface 305. The ultra-hard cutting element 300 also includes a circumferential edge 307 at the interface between the outer formation-engaging surface 305 and the cylindrical sidewall 304 of the base portion 301. The extension portion 302 has a height H" defined between the center 306 and a plane that is perpendicular to the longitudinal axis A" and extends through the circumferential edge 307. The outer formation-engaging surface 305 of the extension portion 302 also has a radius of curvature R". In one embodiment, at least a portion of the outer formation-engaging surface 305 may be formed from any material having highly abrasive and/or wear-resistant properties, such as, for instance, one or more of the materials of the outer formation-engaging surface 113, 205 described above with reference to the embodiment of the ultra-hard cutting element 102, 200 illustrated in FIGS. 2A, 2B and FIGS. 3A, 3B, respectively (e.g., PCD, PCBN, and/or any material having a hardness greater than or equal to approximately 4000 kg/mm²). Although in one embodiment only the outer formation-engaging surface 305 (or a portion thereof) of the extension portion 302 is formed from PCD or PCBN, in one or more embodiments, any other suitable portion of the extension portion 302 may be formed from PCD or PCBN. For instance, in one embodiment, all or substantially all of the extension portion 302 may be formed from PCD or PCBN.

[0037] Still referring to the embodiment illustrated in FIGS. 4A and 4B, the ultra-hard cutting element 300 also includes a pair of ridges or lips 308, 309 on the outer formation-engaging surface 305. In the illustrated embodiment, the first lip 308 extends radially outward from the center 306 toward the circumferential interface edge 307 in a first direction and the second lip 309 extends radially outward from the center 306 toward the circumferential interface edge 307 in a second direction. In the illustrated embodiment, the first and second lips 308, 309 extend radially outward from the center 306 in opposite directions (i.e., the first and second lips 308, 309 are angularly spaced apart along the circumferential interface edge 307 by an angle μ' of approximately 180°). In one or more alternate embodiments, the lips 308, 309 may be spaced apart by any other suitable angle μ'. Although in the illustrated embodiment, the ultra-hard cutting element 300 includes two lips 308, 309, in one or more alternate embodiments, the ultra-hard cutting element 300 may include any other suitable number of lips 308, 309, such as, for instance, from one to eight lips. For instance, in one embodiment, the ultra-hard cutting element 300 may include four lips equally spaced apart by an angle μ' of approximately 90°. Additionally, in one embodiment in which the ultra-hard cutting element 300 includes three or more lips, the lips may not be equally spaced apart. Furthermore, in the illustrated embodiment, the lips 308, 309 extend from the center 306 to the circumferential interface edge 307, although in one or more alternate embodiments, the lips 308, 309 may not extend completely to the circumferential interface edge 307 and/or may not extend completely to the center 306. Furthermore, although in the illustrated embodiment the lips 308, 309 are straight or substantially straight, in one or more embodiments, the lips 308, 309 may not be straight (e.g., the lips 308, 309 may be curved such that the lips 308, 309 are arranged in a spiral pattern). Additionally, although in the illustrated embodiment the lips 308, 309 together extend diametrically across the extension portion 302 such that the lips 308, 309 pass through the longitudinal axis A", in one or more alternate embodiments, one or more of the lips 308, 309 may be offset (i.e., spaced apart) from the longitudinal axis A" by any suitable distance. In an embodiment in which one or more of the lips 308, 309 are spaced apart from the longitudinal axis A", one or more of the outer ends of the lips 308, 309 may not be orthogonal to the circumferential interface edge 307 (e.g., one or more of the outer ends of the lips 308, 309 may be oriented at an acute angle relative to the circumferential interface edge 307). In one embodiment, at least a portion of the lips 308, 309 may be formed from any material having highly abrasive and/or wear-resistant properties, such as, for instance, PCD, PCBN, and/or any material having a hardness greater than or equal to approximately 4000 kg/mm²).

[0038] In the illustrated embodiment, the lips 308, 309 segment or divide the outer formation- engaging surface 305 into a first portion 310 and a second portion 311. In one or more alternate embodiments, the outer formation-engaging surface 305 may be divided into any other number of portions depending on the number of lips 308, 309. Unlike the lips 208, 209 described above with reference to the embodiment of the ultra-hard cutting element 200 illustrated in FIGS. 3A and 3B, the lips 308, 309 in FIGS. 4A and 4B project above both the first and second portions 310, 311 of the outer formation-engaging surface 305. Accordingly, when the ultra-hard cutting element 300 is used in a rotary hammer or hammer drilling operation, the hammering force is concentrated on the lips 308, 309 because the lips 308, 309 project above the first and second portions 310, 311 of the outer formation-engaging surface 305 (i.e., the hammering force imparted to the ultra-hard cutting element 300 during a drilling operation is initially concentrated on the lips 308, 309, rather than distributed across the area of the outer formation-engaging surface 305). The concentration of the hammering force onto the lips 308, 309 may increase the rate of penetration of the drill bit 100 incorporating the ultra-hard cutting element 300 into a structure compared to conventional drill bits.

[0039] In one embodiment, the ultra-hard cutting element 300 may include one or more transition layers (e.g., a diamond-tungsten carbide composite material). For instance, in one embodiment, the ultra-hard cutting element 300 may include a transition layer between the PCD or PCBN outer formation-engaging surface 305 and the lips 308, 309 and an inner portion of the ultra-hard cutting element 300 formed from tungsten carbide. The material of the transition layer may be selected such that the transition layer has a coefficient of thermal expansion that is between a coefficient of thermal expansion of the PCD or PCBN outer formation-engaging surface 305 and the lips 308, 309 and a coefficient of thermal expansion of tungsten carbide of the inner portion of the ultra-hard cutting element 300. In one embodiment, the material of the transition layer may also be selected such that the transition layer has an elastic modulus that is between the elastic modulus of the PCD or PCBN outer formation-engaging surface 305 and the lips 308, 309 and the elastic modulus of the tungsten carbide of the inner portion of the ultra-hard cutting element 300. In one embodiment, a portion of the transition layer may be infiltrated into the interstitial spaces defined between the network of interconnected crystals of the PCD or PCBN outer formation-engaging surface 305 and/or the PCD or PCBN lips 308, 309 (e.g., cobalt from the transition layer may be infiltrated into the PCD or PCBN on the outer formation-engaging surface 305 and/or infiltrated into the PCD or PCBN on the lips 308, 309). Additionally, in one or more embodiments, the material properties of at least one of the first portion 310, the second portion 311, the first lip 308, and the second lip 309 may be different than the material properties of at least one of the other portions 310, 311 or one of the other lips 308,

309. For instance, in one embodiment, one of the first portion 310, the second portion 311, the first lip 308, or the second lip 309 may have a hardness less than one of the other portions 310, 311 or one of the other lips 308, 309 by approximately 500 kg/mm² to approximately 2500 kg/mm², such as, for instance, by approximately 2200 kg/mm².

[0040] In the illustrated embodiment, each lip 308, 309 includes a cutting face 312, 313 configured cut into a structure (e.g., a masonry or cement structure) when the ultra-hard cutting element 300 is rotated against the structure. In the illustrated embodiment, the cutting faces 312, 313 of the lips 308, 309 are perpendicular or substantially perpendicular to the first and second portions

310, 311, respectively, of the outer formation-engaging surface 305. In one or more alternate embodiments, the cutting faces 312, 313 of the lips 308, 309 may be canted at angles relative to planes perpendicular to the first and second portions 310, 311 of the outer formation-engaging surface 305. In the illustrated embodiment, the cutting face 312 of the first lip 308 is aligned with the cutting face 313 of the second lip 309, although in one or more alternate embodiments the cutting face 312 of the first lip 308 may not be aligned with the cutting face 313 of the second lip 309. Additionally, in the illustrated embodiment, outer ends 314, 315 of the cutting faces 312, 313 are rounded such that the lips 308, 309 blend into the first and second portions 310, 311, respectively, of the outer formation-engaging surface 305. In one or more alternate embodiments, the outer ends 314, 315 of the cutting faces 312, 313 may define sharp edges. In one or more alternate embodiments, one or more of the outer ends 314, 315 of the cutting faces 312, 313 may include a chamfer. Opposite sides of the chamfers may be either rounded (e.g., include a radius) or may define sharp edges. Additionally, in one embodiment, inner ends 316, 317 of the cutting faces 312, 313 may be rounded such that the lips 308, 309 blend into the second and first portions 311, 310, respectively, of the outer formation-engaging surface 205, although in one or more alternate embodiments, the inner ends 316, 317 of the lips 308, 309 may define sharp edges. Furthermore, in the illustrated embodiment, the cutting faces 312, 313 of the lips 308, 309 face in opposite directions. Accordingly, during a drilling operation (e.g., a rotary percussive drilling operation or a rotary drilling operation), both lips 308, 309 are configured to engage and cut into the structure (i.e., during a drilling operation, both of the opposing cutting faces 312, 313 of the lips 308, 309 are advanced into the structure).

[0041] A height h' of the lips 308, 309 is defined between the inner ends 316, 317 and the outer ends 314, 315 of the cutting faces 312, 313, respectively. In the illustrated embodiment, the height h' of each of the lips 308, 309 tapers between a highest point at or proximate the center 306 (i.e., the intersection between the longitudinal axis A" and the outer formation-engaging surface 305) and a lowest point proximate the circumferential interface edge 307 where the outer formation-engaging surface 305 joins the sidewall 304 of the base portion 301. In one or more embodiments, the highest points of the lips 308, 309 may be at any other suitable locations, such as, for instance, at intermediate points between the center 306 and the circumferential interface edge 307 or proximate the circumferential interface edge 307. Additionally, in the illustrated embodiment, the height h' of each of the lips 308, 309 at or proximate the circumferential interface edge 307 is zero or substantially zero. In one or more alternate embodiments, the height h' of each of the lips 308, 309 may be constant or substantially constant along the length of each of the lips 308, 309. In one or more embodiments, the lips 308, 309 may include a segment or a portion that has a constant or substantially constant height and a segment that tapers between a higher end and a lower end. In one embodiment, the height h' of the lips 308, 309 may not taper uniformly. The lips 308, 309 may have any suitable maximum height h' depending, for instance, on the desired performance characteristics of the ultra- hard cutting element 300 and the composition of the material the ultra-hard cutting element 300 is intended to drill through. In one or more embodiments, the ratio of the maximum height h' of the lips 308, 309 to the diameter D' of the cylindrical sidewall 304 of the ultra-hard cutting element 300 may be from approximately 0.01 to approximately 0.4. In one or more embodiments, the ratio of the maximum height h' of the lips 308, 309 to the diameter D' of the cylindrical sidewall 304 of the ultra- hard cutting element 300 may be from approximately 0.01 to approximately 0.1. In one or more embodiments, the ratio of the maximum height h' of the lips 308, 309 to the diameter D' of the cylindrical sidewall 304 may be greater than 0.4. In another embodiment, the ratio of the maximum height h' of the lips 308, 309 to the diameter D' of the cylindrical sidewall 304 may be less than 0.01.

[0042] Still referring to the embodiment illustrated in FIGS. 4A and 4B, the ultra-hard cutting element 300 also defines a plurality of flutes 318 extending between the first and second portions 310, 311, respectively, of the outer formation-engaging surface 305 and the circular base 303 of the base portion 301. Although in the illustrated embodiment the flutes 318 have a semicircular cross- sectional shape in a plane perpendicular to the longitudinal axis A", in one or more embodiments, the flutes 318 may have any other suitable cross-sectional shape, such as, for instance, a tapered cross-sectional shape (e.g., wedge-shaped). Additionally, although in the illustrated embodiment the flutes 318 extend axially along the cylindrical sidewall 304 of the base portion 301 (e.g., the flutes 318 extend parallel or substantially parallel to the longitudinal axis A"), in one or more embodiments, the flutes 318 may be curved (e.g., the flutes 318 may extend helically around the longitudinal axis A").

[0043] Additionally, in the illustrated embodiment, the lips 308, 309 on the outer formation- engaging surface 305 are tangential to the flutes 318 defined in the ultra-hard cutting element 300. In the illustrated embodiment, the lips 308, 309 intersect the circumferential interface edge 307 at the same point that an edge 319 of the flutes 318 intersects the circumferential interface edge 307. Accordingly, in the illustrated the lips 308, 309 and the flutes 318 are positioned such that the lips 308, 309 are configured to direct the formation cuttings into the flutes 318 during a drilling operation. Accordingly, in the illustrated embodiment, the flutes 318 are angularly spaced apart by the same or substantially the same angle μ' as the lips 308, 309. In one or more alternate embodiments, the lips 308, 309 may have any other suitable position on the outer formation-engage surface 305 relative to the flutes 318.

[0044] With reference now to FIGS. 5 and 6, a method 400 of manufacturing a drill bit 100 (see FIG. 1) according to one embodiment of the present disclosure includes a task 410 of forming an ultra-hard cutting element (e.g., an ultra-hard cutting element 102, 200, 300 according to one embodiment described above with reference to FIGS. 2A-4B). In one embodiment, the task 410 of forming the ultra-hard cutting element 102, 200, 300 includes inserting a plurality of solid particulates 501 into a deformable can 502. In the illustrated embodiment, the deformable can 502 is a hollow shell having an open upper end 503. In one or more embodiments, the solid particulates 501 may be or include diamond (e.g., diamond crystals), cobalt, tungsten, cubic boron nitride, or any combination thereof. In one embodiment, the composition of the solid particulates 501 may be selected to include highly abrasive and/or wear-resistant properties depending, for instance, on the desired performance characteristics of the ultra-hard cutting element 102, 200, 300 and/or the composition of the material the ultra-hard cutting element 102, 200, 300 is intended to drill through. Additionally, in one or more embodiments, the task 410 may include inserting a transition layer material into the can 502. The solid particulates 501 of the ultra-hard material and/or the transition layer may also include one or more binder materials. The binder serves to bond the particles together during a subsequent task of forming and shaping the layers of the ultra-hard cutting element 102, 200, 300. The binder material may be any suitable material or materials, such as, for instance, various waxes, polymers, or other organic materials. The binder material may be subsequently removed from the layers following the formation of the ultra-hard cutting element 102, 200, 300 by any suitable manufacturing process or technique, such as, for instance, by chemical reaction, high-temperature decomposition, and/or solvent extraction.

[0045] With continued reference to FIGS. 5 and 6, the task 410 of forming the ultra-hard cutting element 102, 200, 300 also includes at least partially inserting a substrate 504 into the can 502 through the open upper end 503. In the illustrated embodiment, the substrate 504 includes a base portion 505 and an extension portion 506 extending from one end of the base portion 505. Additionally, in the illustrated embodiment, the base portion 505 is cylindrical and the extension portion 506 is spherical (e.g., hemispherical or a spherical cap or dome), although in one or more alternate embodiments the substrate 504 may have any other suitable shape depending on the desired shape of the ultra-hard cutting element 102, 200, 300. The substrate 504 maybe formed from any suitable strong and durable material, such as, for instance, tungsten carbide. The material of the substrate 504 may also be selected to facilitate coupling the ultra-hard cutting element 102, 200, 300 to a shank (see FIG. 1) (e.g., by welding or brazing) to form the drill bit 100 during a subsequent task, described below.

[0046] With continued reference to FIGS. 5 and 6, the task 410 of forming the ultra-hard cutting element 102, 200, 300 also includes pressing the can 502, and the substrate 504 at least partially received therein, down onto a forming device 507. In the illustrated embodiment, the forming device 507 includes a recess 508 configured to receive at least a portion of the can 502 and the substrate 504 received therein. In the illustrated embodiment, an inner surface 509 of the recess 508 in the forming device 507 is spherical (e.g., hemispherical or a spherical cap or dome). The inner surface 509 of the recess 508 in the forming device 507 may include one or more protrusions and/or one or more depressions 510. The protrusions are configured to deform the can 502, the solid particulates 501, and the extension portion 506 of the substrate 504 into the shape of the inner surface 509 of the forming device 507 when the can 502 and the substrate 504 are pressed onto the forming device 507. In one embodiment, the forming device 507 may be configured not to deform the extension portion 506 of the substrate 504. In one or more alternate embodiments, the can 502 may not be deformable and the can 502 may be pre-formed or pre-shaped into the desired shape (or a portion thereof) of the ultra-hard cutting element 102, 200, 300.

[0047] The depressions 510 are configured to form one or more lips (e.g., lips 208, 209 in FIGS. 3A and 3B or lips 308, 309 in FIGS. 4A and 4B). The shape, size, and orientation of the depressions 510 in the forming device 507 correspond to the desired configuration of the lips on the outer formation-engaging surface of the ultra-hard cutting element 102, 200, 300. Accordingly, in one or more embodiments, the inner surface 509 of the recess 508 in the forming device 507 may be a negative impression that corresponds to the desired shape of the outer formation-engaging surface of the ultra-hard cutting element 102, 200, 300. In the illustrated embodiment, the inner surface 509 of the forming device 507 includes a pair of depressions 510 extending radially outward in opposite directions from a center point of the inner surface 509. In one or more alternate embodiments, the inner surface 509 of the forming device 507 may be provided without depressions. For instance, the forming device 507 may be provided without depressions to form an ultra-hard cutting element having a smooth outer surface, as shown, for example, in the embodiment of the ultra-hard cutting element 102 in FIGS. 2A and 2B.

[0048] Pressing the can 502 and the substrate 504 onto the forming device 507 may also cause the solid particulates 501 (e.g., diamond powder) to become a solid mass. Pressing the can 502 and the substrate 504 onto the forming device 507 may also create a connection (e.g., a press-fit connection) between the solid particulate mass 501 and an outer surface 510 of the extension portion 506 of the substrate 504.

[0049] Still referring to FIGS. 5 and 6, the task 410 of forming the ultra-hard cutting element 102, 200, 300 also includes exposing the substrate 504 and the solid particulate mass 501 to a high pressure, high temperature ("HPHT") sintering process. The HPHT sintering process may be performing during or after the process of pressing the can 502 and the substrate 504 onto the forming device 507. In an embodiment in which the solid particulates 501 include diamond powder, the HPHT sintering process causes the solid particulate mass 501 to form into a polycrystalline diamond structure having a network of intercrystalline bonded diamond crystals.

[0050] A catalyst material may be used to facilitate and promote the inter-crystalline bonding of the diamond crystals. In one or more embodiments, the catalyst material may be mixed into the diamond powder prior to the HPTP sintering process and/or may infiltrate the diamond powder from an adjacent substrate during the HPHT sintering process. The HPHT sintering process creates a polycrystalline diamond structure having a network of intercrystalline bonded diamond crystals, with the catalyst material remaining in interstitial spaces (e.g., voids or gaps) between the bonded diamond crystals. In one embodiment, the catalyst material may be a solvent catalyst metal selected from Group VIII of the Periodic table (e.g., iron), Group IX of the Periodic table (e.g., cobalt), or Group X of the Periodic table (e.g., nickel). Accordingly, the HPHT sintering process forms the ultra-hard cutting element 102, 200, 300 having a substrate 504 and solid particulate mass 501 (e.g., polycrystalline diamond structure) coupled to the outer surface 510 of the substrate 504. The ultra- hard cutting element 102, 200, 300 may be removed from the can 502 and the forming device 507 following the HPHT sintering process.

[0051] The method also includes a task 420 of forming one or more flutes (e.g., flutes 116 in FIGS. 2A and 2B, flutes 224 in FIGS. 3A and 3B, or flutes 318 in FIGS. 4A and 4B) in the ultra- hard cutting element 102, 200, 300. In one embodiment, the task 420 of forming the flutes in the ultra-hard cutting element 102, 200, 300 includes electro discharge machining (EDM) the ultra-hard cutting element 102, 200, 300 to remove at least a portion of substrate 504, and at least a portion of the solid particulate mass 501 (e.g., polycrystalline diamond structure) coupled to the outer surface 510 of the substrate 504, corresponding to the desired size, shape, and orientation of the flutes. In one or more embodiments, the task 420 of forming the flutes in the ultra-hard cutting element 102, 200, 300 may include any other suitable manufacturing technique or process, such as, for instance, grinding (e.g., diamond or glass grinding). In an alternate embodiment, the flutes may be formed during the task 410 of forming the ultra-hard cutting element 102, 200, 300. For instance, in one embodiment, the can 502 and the substrate 504 may include depressions corresponding to the desired shape, size, and orientation of the flutes in the ultra-hard cutting element 102, 200, 300.

[0052] The method may also include a task 430 of coupling the ultra-hard cutting element 102, 200, 300 to a shank to form the drill bit. In one embodiment, the task 430 of coupling the ultra-hard cutting element 102, 200, 300 to the shank includes brazing the ultra-hard cutting element 102, 200, 300 to the shank. In one or more embodiments, the task 430 of coupling the ultra-hard cutting element 102, 200, 300 to the shank may include any other suitable manufacturing technique or process, such as, for instance, welding (e.g., laser beam welding). The method 400 of forming the drill bit may include forming the shank or obtaining or providing a pre-formed shank. The shank may be made out of any suitably strong and durable material, such as, for instance, steel or tungsten carbide. The shank may also be made out of any material suitable to facilitate coupling the ultra-hard cutting element 102, 200, 300 to the shank.

[0053] While this invention has been described in detail with particular references to embodiments thereof, the embodiments described herein are not intended to be exhaustive or to limit the scope of the invention to the exact forms disclosed. Persons skilled in the art and technology to which this invention pertains will appreciate that alterations and changes in the described structures and methods of assembly and operation can be practiced without meaningfully departing from the principles, spirit, and scope of this invention. Additionally, as used herein, the term "substantially" and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Furthermore, as used herein, when a component is referred to as being "on" or "coupled to" another component, it can be directly on or attached to the other component or intervening components may be present therebetween.

Claims

WHAT IS CLAIMED IS:

1. A drill bit, comprising:

a shank;

an ultra-hard cutting element coupled to the shank, wherein at least a portion of an outer surface of the ultra-hard cutting element includes an ultra-hard abrasive material; and

at least one flute defined in the ultra-hard cutting element.

2. The drill bit of claim 1 , wherein the ultra-hard abrasive material is selected from the group of materials consisting of polycrystallme diamond and polycrystallme cubic boron nitride.

3. The drill bit of claim 1 , wherein at least a portion of the ultra-hard abrasive material has a hardness of at least approximately 4000 kg/mm².

4. The drill bit of claim 1 , wherein the outer surface of the ultra-hard cutting element is substantially spherical.

5. The drill bit of claim 1 , further comprising at least one angled notch extending from the outer surface of the ultra-hard cutting element to an outer end of the at least one flute.

6. The drill bit of claim 1 , wherein the ultra-hard cutting element further comprises a lip extending radially across at least a portion of the outer surface.

7. The drill bit of claim 1, wherein:

the shank is a cylindrical member defining a plurality of helical flutes, and

the ultra-hard cutting element defines a plurality of flutes, wherein each of the flutes in the ultra-hard cutting element is aligned with a respective one of the helical flutes in the shank.

8. The drill bit of claim 7, wherein each of the plurality of flutes defined in the ultra- hard cutting element is helical.

9. The drill bit of claim 7, wherein each of the plurality of flutes defined in the ultra- hard cutting element is axial.

10. An ultra-hard cutting element, comprising:

a base portion defining a longitudinal axis;

an extension portion on an end of the base portion, wherein at least a portion of an outer surface of the extension portion includes an ultra-hard abrasive material; and

at least one lip on the outer surface of the extension portion, the at least one lip having a length between a first end and a second end.

11. The ultra-hard cutting element of claim 10, wherein the ultra-hard abrasive material is selected from the group of materials consisting of polycrystallme diamond and polycrystallme cubic boron nitride.

12. The ultra-hard cutting element of claim 10, wherein the outer surface of the ultra-hard cutting element is substantially spherical.

13. The ultra-hard cutting element of claim 10, wherein the at least one lip extends radially across at least a portion of the outer surface.

14. The ultra-hard cutting element of claim 10, wherein a height of the at least one lip tapers between a higher end proximate the longitudinal axis and a lower end proximate an interface edge between the outer surface and a sidewall of the base portion.

15. The ultra-hard cutting element of claim 10, wherein a height of the lip is substantially constant along the length of the lip.

16. The ultra-hard cutting element of claim 10, wherein the at least one lip is defined by a depression in the outer surface of the extension portion.

17. The ultra-hard cutting element of claim 10, wherein the at least one lip projects beyond the outer surface of the extension portion.

18. The ultra-hard cutting element of claim 10, wherein the at least one lip comprises: a first lip extending radially across the outer surface in a first direction; and

a second lip extending radially across the outer surface in a second direction different than the first direction.

19. The ultra-hard cutting element of claim 18, wherein the second direction is opposite the first direction.

20. The ultra-hard cutting element of claim 19, wherein each of the first and second lips comprises a cutting face, and wherein the cutting face of the first lip faces in a direction opposite the cutting face of the second lip.

21. A method of manufacturing a drill bit, comprising: coupling an ultra-hard cutting element to a shank, wherein an outer surface of the ultra-hard cutting element comprises an ultra-hard abrasive material selected from the group of materials consisting of poly crystalline diamond and poly crystalline cubic boron nitride.

22. The method of claim 21 , wherein the coupling of the ultra-hard cutting element to the shank comprises brazing the ultra-hard cutting element to the shank.

23. The method of claim 21 , wherein coupling the ultra-hard cutting element to the shank comprises welding the ultra-hard cutting element to the shank.

24. The method of claim 21, further comprising forming the ultra-hard cutting element before the coupling of the ultra-hard cutting element to the shank, wherein the forming of the ultra- hard cutting element comprises high pressure, high temperature sintering a mixture of at least one of diamond particles and cubic boron nitride particles and at least one of a catalyst material and a ceramic binder material to a substrate.

25. The method of claim 24, whether the forming of the ultra-hard cutting element further comprises forming at least one lip extending radially across at least a portion of the outer surface.

26. The method of claim 25, wherein the forming of the at least one lip comprises: inserting the mixture in a deformable can; and

deforming at least a portion of the mixture and the deformable can with a forming device.

27. The method of claim 24, further comprising forming a plurality of flutes in the ultra- hard cutting element.

28. The method of claim 27, wherein the forming of the plurality of flutes comprises electrical discharge machining the plurality of flutes.