POLYCRYSTALLINE DIAMOND CUTTER WITH INTEGRAL POLYCRYSTALLINE DIAMOND LINED PASSAGE
Provided are polycrystalline diamond cutters including a substrate, a diamond body, and a passage extending through the cutter along an axis from an opening in a lower side of the substrate to an opening in a first side of a diamond body. The diamond body may have a planar oriented portion and a projecting portion. The planar oriented portion of the diamond body may be attached to the upper side of the substrate and the projecting portion of the diamond body may form at least a portion of an inner wall surface of the first passage.
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TECHNICAL FIELD AND INDUSTRIAL APPLICABILITYThe present disclosure relates generally to polycrystalline diamond cutters. Specifically, the present disclosure relates to polycrystalline diamond cutters incorporating an axially oriented passage through the cutter that is lined with polycrystalline diamond and methods to manufacture such polycrystalline diamond cutters.
BACKGROUNDIn the discussion that follows, reference is made to certain structures and/or methods. However, the following references should not be construed as an admission that these structures and/or methods constitute prior art. Applicant expressly reserves the right to demonstrate that such structures and/or methods do not qualify as prior art against the present invention.
Tools used in the drilling industry, such as drag bits 10 (see
Diamond tables and polycrystalline diamond cutters can be formed by sintering diamond particles under high pressure and high temperature conditions in the presence of a metal catalyst, such as cobalt (Co). The metal catalyst can originate from an independent source, such as a metal catalyst powder blended into the diamond particles or metal catalyst powder or foil adjacent the diamond particles or from a substrate material as described below. Conventional HPHT conditions include pressures at or above about 4-5 GPa and temperatures at or above about 1200° C. Typically, under the HPHT processing conditions, binder material present in an independent source or in a substrate (typically a cemented carbide substrate) positioned adjacent to diamond powders melts and sweeps into the mass of diamond. When a substrate is present, the binder material of the substrate can act as a metal catalyst in the diamond powders. In the presence of the metal catalyst, diamond crystals are bonded to each other in diamond-to-diamond bonds by a dissolution-precipitation process to form a sintered compact in which polycrystalline diamond mass, i.e., a diamond table, is formed which is attached to the substrate (if present). The presence of the metal catalyst facilitates formation of diamond-to-diamond bonds and, where applicable, the attachment of the diamond table to the substrate. However, the metal catalyst remains in the diamond table after the HPHT sintering process, and the presence of the metal catalyst is detrimental to polycrystalline diamond performance when used in cutting and machining applications. In particular, the presence of the metal catalyst in the sintered polycrystalline diamond compact may have detrimental effects on the mechanical properties of the polycrystalline diamond cutter when used in intended applications, such as drilling geologic formations.
The polycrystalline diamond cutter 20 may be later machined to a desired shape, including machining to specified outer diameter, height and the addition of any chamfers or beveled surfaces. Examples of chamfers or beveled surfaces 70 can be seen in side view in
Commonly, a polycrystalline diamond cutter is made using a high pressure and high temperature (HPHT) sweep-through process. In the sweep-through process, a mass of diamond crystals is placed into a refractory metal container. The diamond mass may contain some binder material or additives blended in to promote sintering. A cemented carbide substrate is placed in the container such that a surface of the substrate touches the mass of diamond crystals. The assembly is then subjected to HPHT conditions. Typically the binder material present in the substrate melts and sweeps into the mass of diamond crystals. In the presence of the liquefied binder material, diamond crystals bond to each other by a dissolution-precipitation process to form a polycrystalline diamond mass attached to the cemented carbide substrate.
The cemented carbide substrate usually includes small amounts of a binder material, such as cobalt, nickel, iron or their alloys, to improve integrity and strength. The binder material is generally selected to function as a catalyst for melting and sintering the diamond crystals. That is, in existing processes for forming a polycrystalline diamond cutter, the cobalt or other binder material from the substrate will melt under HPHT conditions from the carbide substrate and “sweep” across the diamond powder to create the polycrystalline diamond cutter. The sweep occurs as a front that moves from an interface between the substrate and the diamond crystals toward a distal surface of the diamond. If the interface between the substrate and the diamond is planar, the sweep may be uniform.
Polycrystalline diamond demonstrates wear and thermal properties that are advantageous in drilling operations. However, the presence in polycrystalline diamond compacts of catalyst promotes degradation of the cutting edge of the cutter during the cutting process, especially if the edge temperature reaches a high enough critical value. Probably, this catalyst driven degradation is caused by the graphitization of diamond. Such graphitization is known to occur at temperatures of about 700° C. and above and can cause ruptures to occur in the diamond-to-diamond bonding, and eventually result in the formation of cracks and chips in the polycrystalline diamond structure, rendering the polycrystalline diamond cutter unsuited for further use.
SUMMARYFor polycrystalline diamond cutters, it would be beneficial to mitigate thermally induced degradation. Thus, there is a need for structures and techniques that provide thermal management of the polycrystalline diamond cutter to improve the wear and thermal performance.
In one embodiment, a polycrystalline diamond cutter, comprises a substrate including an upper side, a lower side opposite the upper side, and at least one edge side connecting the upper side to the lower side, a diamond body including a planar oriented portion and a projecting portion, and a first passage extending through the cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body, wherein the planar oriented portion of the diamond body is attached to the upper side of the substrate, and wherein the projecting portion of the diamond body forms at least a portion of an inner wall surface of the first passage.
In another embodiment, a method of making a polycrystalline diamond cutter comprises forming an assembly, wherein the assembly comprises a substrate having a channel extending through a body of the substrate from a first opening in a lower side to a second opening in an upper side, a layer of diamond feed in contact with surfaces of the channel and with one of the lower side and upper side, and a refractory container including a tube portion inserted into the channel, adding poisoned diamond feed into an interior volume of the tube portion to form a poisoned assembly, and processing the poisoned assembly at elevated temperature and elevated pressure sufficient to sinter the diamond feed into a diamond body, wherein the diamond body includes a planar oriented portion attached to one of the lower side and upper side of the substrate, and wherein the diamond body includes a projecting portion attached to surfaces of the channel and forming at least a portion of an inner wall surface of a passage extending through the cutter on an axis.
In a further embodiment, a method of making a polycrystalline diamond cutter comprises forming an assembly, wherein the assembly comprises a substrate having a channel extending through a body of the substrate from a first opening in a lower side to a second opening in an upper side, a layer of diamond feed in contact with surfaces of the channel and with one of the lower side and upper side, and a refractory container, processing the assembly at elevated temperature and elevated pressure sufficient to sinter the diamond feed into a diamond body, wherein the diamond body includes a planar oriented portion attached to one of the lower side and upper side of the substrate, and wherein the diamond body includes a projecting portion filling the channel, and making a passage extending through the polycrystalline diamond cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body.
The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown.
The substrate 110 has body 150 with an upper side 160, a lower side 170 opposite the upper side 160, and at least one edge side 180 connecting the upper side 160 and the lower side 170, e.g., at a corner 190. For example, when the cutter 100 is in the shape of a cylinder, the outer cylindrical surface is the at least one edge side. In addition, the substrate has a channel 200 that extends through the substrate body 150 from a first opening 210 in the lower side 170 to a second opening 220 in the upper side 160. Typically, the channel 200 is a bore having a cylindrical shape and is coaxially located with axis 140. However, the channel 200 can be other shapes or can be offset from axis 140 or angled with respect to axis 140 or one or more of these variations from that depicted in
The diamond body 120 includes a planar oriented portion 240 and a projecting portion 250 and is continuous from the radial outer edge side of the planar oriented portion 240 to an axially most distant end of the projecting portion 250. The planar oriented portion 240 lies in a plane substantially perpendicular to axis 140 and has an upper side 260 and a lower side 270 and a thickness L1, in the axial direction, i.e., parallel to axis 140, of about 0.5 mm to 5.0 mm, alternatively about 2.0 mm. An edge side 280 connects the upper side 260 and the lower side 270, e.g., at a corner 290. The projecting portion 250 protrudes from the lower side 270 of the planar portion 250 a distance L2 in a direction substantially parallel, alternatively coaxial with, axis 140 and terminates in a distal end 300. The projecting portion 250 has outer surface 310 and a passage 320 that extends from a first opening 330 in the upper side 260 of the planar oriented portion 240 to second opening 340 at the distal end 300 of the projecting portion 250 and has an inner surface 350. In exemplary embodiments, the passage 310 is coaxial with axis 140 and is also coaxial with channel 200 of the substrate 110. In the exemplary embodiment shown, the surface 360 of the distal end 300 is planar and is oriented in a plane perpendicular to the axis 140 and, when viewed along axis 140, forms an annulus.
In the assembled form of the cutter 100, the planar oriented portion 240 of the diamond body 120 is attached to the upper side 160 of the substrate 110. Additionally, in the assembled form of the cutter 100, the projecting portion 250 of the diamond body 120 is located within at least a portion of the channel 200 in the substrate 110 and is attached to at least a portion of the surface 230 of the channel 200 to form at least a portion of an inner wall surface; alternatively the projecting portion 250 is attached to and runs the length of the entire surface 230 of the channel 200.
The composition of the diamond body can be sintered diamond particle sizes between about 1 micron to about 50 microns and a catalyst metal phase between about 8 percent by weight (wt. %) to about 25 percent by weight (wt. %). The diamond body 120 is formed integrally to the substrate through a high pressure—high temperature sintering process as described herein during which metal catalyst diffuses into the diamond body and not only densifies the diamond body, but also serves to mechanically bond the diamond body to the substrate.
The substrate 110 can be any suitable substrate that can be processed in the high pressure—high temperature sintering environment used to consolidate and sinter the polycrystalline diamond particles into the diamond body and to bond the diamond body to the substrate. Further, the composition of the substrate typically includes a metal catalyst. In exemplary embodiments, the substrate is a hard metal alloy or composite, a cemented carbide, or cobalt sintered tungsten carbide (WC—Co). In preferred embodiments, the substrate is cobalt sintered tungsten carbide and has a composition of 8-15 wt. % cobalt and 85-92 wt. % tungsten carbide and, optionally, 0.3-2.5 wt. % chromium.
Before describing the methods in more detail, reference is made to
Although one embodiment of a refractory container includes a tube portion, such embodiments are preferably used when the tube portion imparts the feature of the passage or the feature of a shaped portion of the in the polycrystalline diamond cutter during the high pressure—high temperature process. Other embodiments of the refractory container without the tube portion feature can also be used, particularly where the feature of the passage in the polycrystalline diamond cutter is imparted through a separate manufacturing process applied to the diamond body.
The refractory container is typically made from a refractory alloy such as tantalum (Ta), niobium (Nb), molybdenum (Mo), and zirconium (Zr), with tantalum being the preferred material. The refractory container can be made by any suitable method. However, it is preferred that the refractory container is seamless and is formed by a sheet metal forming process that includes a drawing operation, preferably deep drawing. When a tube portion is present, it also can be formed by a sheet metal forming process that includes a drawing operation, preferably deep drawing.
Turning back to the methods and with reference to
The assembly can be formed in one of several ways. In a first method, a layer of diamond feed is formed in the refractory container 410a. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that includes a tube portion. The diamond feed is distributed in a layer on the bottom of the refractory container and has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1 mm and 5 mm.
A substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 410b. The substrate is positioned in the refractory container with the upper side of the substrate in contact with the layer of diamond feed. Additionally, the substrate is positioned such that the tube portion of the refractory container extends through the channel in the substrate.
Typically, the tube portion will extend through the channel and past the lower surface of the substrate. Also, there is typically a clearance space between the surfaces of the tube portion and the surfaces of the channel. Accordingly, diamond feed is added into this clearance space 410c. The diamond feed added into the clearance space contacts the diamond feed already present in the layer of diamond feed formed previously (see 410a) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the clearance space. The diamond feed in the clearance space can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. Alternatively, the diamond body can be formed along less than the entire length of the tube by using a substrate geometry which closes off the channel at the bottom, thereby preventing diamond from forming in the portion where the substrate is in direct contact with the tube wall. A geometric feature can be imparted to a portion of the diamond body, for example, the portion that corresponds to the distal portion of the projecting portion of the diamond body, by modifying the geometry of the substrate, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.
A cap is subsequently positioned over the opening of the refractory container to cover the contents of the refractory container and the capped refractory container is sealed to form an assembly 430. In one embodiment, the cap can have a shape similar to the container 600,600′ but without a tube portion and having a diameter of the opening that is sufficiently larger than the diameter of the container 600,600′ so that the cap can slide over at least a portion of the distance d of the outer peripheral surfaces of the container in a telescoping manner to form a container-over-container structure. This structure positions the bottom of the interior volume of the cap in contact with the opening 630,630′ in the container 600,600′. Once arranged into the structure, the container and the cap can be crimped or otherwise pressed together so as to seal the cap and the container to form an assembly. In another embodiment, the cap can be a disc or foil or similar planar structure that is placed in the opening 630,630′ of the container 600,600′ over the contents in the container 600,600′ and then the peripheral edge of the cap and the peripheral edge of the opening 630,630′ are crimped or otherwise pressed together or folded over so as to seal the cap and the container to form an assembly. Sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container. The cap is typically of the same material as the refractory container, e.g., tantalum.
In a second method, a substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 420a. The substrate is positioned in the refractory container with the lower side oriented toward the bottom of the refractory container and with the upper side oriented toward the open side of the refractory container. In addition, the substrate is positioned within the refractory container such that the tube portion of the refractory container extends through the channel in the substrate.
Typically, the tube portion will extend through the channel and past the upper surface of the substrate. Also, there is typically a clearance space between the surfaces of the tube portion and the surfaces of the channel. Accordingly, diamond feed is added into this clearance space 420b. The diamond feed can be added by pouring or otherwise adding the diamond feed into the clearance space. The diamond feed in the clearance space can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. Alternatively, the diamond body can be formed along less than the entire length of the tube by using a substrate geometry which closes off the channel at the bottom, thereby preventing sintered diamond from forming in the portion where the substrate is in direct contact with the tube wall. A geometric feature can be imparted to a portion of the diamond body, for example, the portion that corresponds to the distal portion of the projecting portion of the diamond body, by modifying the geometry of the substrate, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.
After the axial length of the clearance space is filled, for example, when the diamond feed extends axially up to the level of the upper surface of the substrate, a layer of diamond feed is formed 420c. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that is above the upper surface of the substrate. The diamond feed added to form the layer contacts the diamond feed already present in the clearance space added previously (see 420b) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the clearance space. Also, the diamond feed is distributed in a layer that is in contact with at least a portion of the upper surface, alternatively in contact with the entire upper surface. The layer has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1.0 mm and 4.0 mm.
A cap is subsequently positioned in the opening of the refractory container to cover the contents of the refractory container and the capped refractory container is sealed to form an assembly 430. In one embodiment, the cap can have a shape similar to the container 600/600′ but without a tube portion and having a diameter of the opening that is sufficiently larger than the diameter of the container 600,600′ so that the cap can slide over at least a portion of the distance d of the outer peripheral surfaces of the container in a telescoping manner to form a container-over-container structure. This structure positions the bottom of the interior volume of the cap in contact with the opening 630,630′ in the container 600,600′. Once arranged into the structure, the container and the cap can be crimped or otherwise pressed together so as to seal the cap and the container to form an assembly. In another embodiment, the cap can be a disc or foil or similar planar structure that is placed over the opening 630,630′ of the container 600,600′ over the contents in the container 600,600′ and then the peripheral edge of the cap and the peripheral edge of the opening 630,630′ are crimped or otherwise pressed together or folded over so as to seal the cap and the container to form an assembly. Sealing can be by any suitable means that secures the cap to the refractory container and secures the contents of the assembly within the capped refractory container. The cap is typically of the same material as the refractory container, e.g., tantalum.
Assemblies formed in the first method (410a, 410b, 410c, 430) and formed in the second method (420a, 420b, 420c, 430) can then be further prepared for processing under high pressure—high temperature (HPHT) processing. Further preparations include 440 placing a non-reactive material in the interior space 650,650′ of the tube portion 640,640′ of the refractory container, preferably to fill the interior space 650,650′. The non-reactive material should be capable of withstanding the high pressure—high temperature processing conditions without reacting with the contents of the assembly and while also transmitting the pressure applied to the assembly. The non-reactive material should also be capable of providing structural rigidity sufficient to approximately maintain the channel geometry at HPHT conditions. An example of a suitable non-reactive material is a diamond feed that has been poisoned to be non-reactive and non-sinterable. Such a poisoned diamond feed has a composition of between about 5 percent and 30 percent by weight talc powder, balance diamond powder. Another example of a suitable non-reactive material is salt. Assemblies to which a non-reactive material has been added are referred to herein as poisoned assemblies.
Although shown in step-wise fashion in
In
In other embodiments discussed herein, the clearance space can extend only a portion of the entire axial length of the channel in the substrate.
As seen in
One or more poisoned assemblies are loaded into a cell for high pressure—high temperature (HPHT) processing 450. Generally, the cell includes a pressure transmitting medium, a heater, the product assembly, and a thermal insulating material. An example of a suitable cell is disclosed in U.S. Pat. No. 4,807,402, the entire contents of which are incorporated herein by reference. The cell is then subjected to high pressure—high temperature (HPHT) processing conditions sufficient to consolidate and sinter the diamond feed into a diamond body that is bonded to the substrate. An example of suitable HPHT processing conditions includes temperatures in the range 1300° C. to 1700° C., pressures in the range 50 kbar to 80 kbar (5 GPa to 8 GPa), and sintering times between about 2 minutes to about 20 minutes. After removing the pressure and allowing the cell to cool, the cell and assembly can be opened and the polycrystalline diamond cutter recovered.
Using the embodiments shown in
Referring back to the methods and with reference to
The assembly can be formed in one of several ways. In a third method, a layer of diamond feed is formed in the refractory container 510a. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container. The diamond feed is distributed in a layer on the bottom of the refractory container and has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1 mm and 5 mm.
A substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 510b. The substrate is positioned in the refractory container with the upper side of the substrate in contact with the layer of diamond feed. Diamond feed is then added into channel of the substrate 510c. The diamond feed added into the channel contacts the diamond feed already present in the layer of diamond feed formed previously (see 510a) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the channel. The diamond feed in the channel can fill the entire clearance space consistent with the length of the channel, in which case the diamond body will be formed along the entire length of the channel. A geometric feature can be imparted to a portion of the diamond body, for example by modifying the shape of channel, such as with a chamfer, an angled surface, a concave surface, a convex surface, or a hyperbolic surface.
To secure the contents of the assembly or poisoned assembly, a cap is placed over the opening of the refractory container or interior cap and sealed. In one embodiment, an example of which is shown in
In a fourth method, a substrate, such as a WC—Co substrate having a channel that extends through the substrate body from a first opening in the lower side to a second opening in the upper side, is positioned in the refractory container 520a. The substrate is positioned in the refractory container with the lower side oriented toward the bottom of the refractory container and with the upper side oriented toward the open side of the refractory container. Diamond feed is added into the channel of the substrate 520b. The diamond feed can be added by pouring or otherwise adding the diamond feed into the channel. The diamond feed in the channel can fill the axial length of the channel, in which case the diamond body will be formed along the entire length of the channel.
After the axial length of the channel is filled, for example, the diamond feed extends axially up to the level of the upper surface of the substrate, a layer of diamond feed is formed 520c. The layer can be formed by pouring or otherwise adding the diamond feed into the interior volume of a refractory container that is above the upper surface of the substrate. The diamond feed added to form the layer contacts the diamond feed already present in the channel added previously (see 520b) so that there is a continuous volume of diamond feed that includes the diamond feed in the layer and the diamond feed in the channel. Also, the diamond feed is distributed in a layer that is in contact with at least a portion of the upper surface, alternatively in contact with the entire upper surface. The layer has a desired distribution and thickness based on the desired distribution and thickness of the diamond body in the finished product. Typically, however, the diamond feed is distributed uniformly in a layer having a thickness of between 1.0 mm and 4.0 mm.
Similar to that described and show in connection with the embodiment in
Returning to
The alternative embodiments in
The various embodiments of the polycrystalline diamond cutter can be further processed to final form. Such processing can include finish wire shaping or grinding of the surfaces of the passage, lapping or grinding of the diamond body to planarize the top surface of the grinder, grinding to add a bevel or chamfer to the diamond body and/or substrate, rotational grinding to finish grind the cylindrical sides of the cutter, and leaching of the metal catalyst in one or more portions of the diamond body.
The features and geometry of the substrate and the diamond body that form the polycrystalline diamond cutter can vary.
For example,
The diameter of the inlet 1230 and the outlet 1260 are both greater than the diameter of the throat 1250, but themselves can either be the same diameter or of different diameters to each other. The absolute and relative sizes of the inlet 1230, outlet 1260 and throat 1250 are such that a coolant liquid or suspension pass freely into the inlet, through the throat, and out from the outlet without blockage and in a manner that removes heat from the cutting edge of the diamond layer. In exemplary embodiments, the diameter of the inlet 1230 can be from about ½ to about ¼ the final diameter of the finished cutter, the diameter of the outlet 1260 can be from about ½ to about ¼ the final diameter of the finished cutter and the diameter of the throat 1250 can be from about ½ to about ¼ the final diameter of the finished cutter. A ratio of dimensions includes: (a) an outlet:inlet ratio between about 1.2-1.6 and (b) an outlet:throat ratio between about 2.0-2.7. Generally, proportions of the passage in the finished cutter, i.e., the channel finished with a portion of the diamond body, will preserve the general shape and parameters of the channel 1210 in the substrate 1200.
Other shapes and geometries of the channel can be used, including full or partial chamfers, angled surfaces, concave surfaces, convex surfaces, or hyperbolic surfaces.
In the exemplary embodiment in
The first side 1350 of the diamond body 1310 has a bevel or chamfer surface 1355 at the corner where the first side 1350 connects to the side surface 1360 of the diamond body 1310. The bevel or chamfer surface 1355 may have a vertical height, i.e., length in the axial direction, of 0.5 mm and an angle of 45 degrees which may provide a particularly strong and fracture resistant tool component. The upper surface of the substrate 1305 also has a bevel or chamfer surface 1365 at the corner where the upper side of the substrate 1305 connects to the side surface 1370 of the substrate 1305 and the lower side of the diamond body 1310 has a surface conformally shaped to and in contact with this bevel or chamfer surface 1365. As seen in
In the exemplary embodiment in
In the embodiment illustrated in
The diamond body 1310 has a shoulder 1420 in the area of the second opening 1345. The shoulder 1420 has an increased radial thickness that provides more volume of diamond body 1310 and an increased wear life of the diamond body 1310 in the area of the shoulder 1420.
The cavity can be formed by machining of the substrate or can be formed in the substrate manufacturing process, for example, by pressing the geometry of the substrate (including the cavity) in a green body using powder metallurgical techniques. Using a suitably formed substrate, a manufacturing method outlined in connection with
In the embodiment illustrated in
The modulation can be periodic or aperiodic. The modulation can also provide a pattern in the top surface, for example the pattern as shown in U.S. Pat. No. 5,484,330, the entire disclosure of which is incorporated herein by reference. In the embodiment illustrated in
The cutter in
In the embodiment illustrated in
The embodiment illustrated in
The cutters in
In the embodiment illustrated in
The cutter in
Although particular features discussed above were discussed in relation to particular cutters in
In general, the surfaces of the passage 1315 transition into the lower side 1340 of the substrate 1305 and into the first side 1350 of the diamond body 1310 at respective openings 1335, 1345. In exemplary embodiments, both transitions can be a curved surface as shown in
In general, the substrate can be manufactured to final shape or near final shape prior to use in the high pressure—high temperature manufacturing operation. For example, the substrate can be formed substantially in the shape of a solid body, such as any type of cylinder or any type of polyhedron, and a channel can be manufactured in the solid body by machining, such as by reaming or drilling. In the case of complex geometries for the substrate or for the channel in the substrate (for example, with the cavity as shown in
The passage and the diamond body, particularly the protruding portion of the diamond body, can take any suitable geometry that allows for one or more of a cooling medium to be transported to the region of the diamond body through the passage, heat to be transported away from the diamond body through the diamond body itself and/or through contact with a medium in the passage, or combinations thereof. In exemplary embodiments, the passage is shaped to impart a venturi effect to the cooling medium. However, in other embodiments, the passage need not follow venturi principles.
Further, the size of the exit opening (i.e., the second opening when the passage is considered as supplying cooling media to the side of the cutter with the planar oriented portion) is between approximately 3 mm and 7 mm diameter, depending on the diameter of the cutter. Larger diameter cutters may use a larger exit hole opening. The size of the entrance hole (i.e., the first opening when the passage is considered as supplying cooling media to the side of the cutter with the planar oriented portion) lies within a similar range, but may be different from the size of the exit hole opening on a given cutter.
In alternative embodiments of the methods disclosed herein, assemblies and poisoned assemblies can employ metal catalyst solid, such as a foil or metal disc, placed at the bottom of the substrate opposite the diamond-substrate interface. A typical metal catalyst solid is a cobalt or cobalt alloy metal disc. The metal body is in direct contact with a portion of the diamond feed, particular a portion located in the channel and, during the HPHT processing, sweeps axially through the diamond feed in the channel. This typically occurs prior to the binder sweep from the substrate. The infiltration of catalyst metal from two sources—binder in the substrate and metal catalyst in foil or disc—contributes to attachment of the diamond table to the substrate.
In a further variation, portions of the diamond body can be leached to remove metal catalyst material from interstitial regions. Removal of metal catalyst from the diamond body, particularly from portions of the diamond body that act as a working surface of the polycrystalline diamond cutter leaves interconnected network of pores and a residual metal catalyst (up to 10 vol. %) trapped inside the polycrystalline diamond body. The removal of metal catalyst, such as cobalt, from diamond bodies significantly improves abrasion resistance of the diamond body. Such leaching can occur in at least a portion of the diamond body and renders the diamond body in that portion substantially free of metal catalyst material. Leaching can occur, for example, by chemical etching in acids in which portions to be leached are exposed to an acid or a mixture of acids, such as aqua regia, for a period of time sufficient to dissolve the catalyst material to a depth from the surface of the diamond body. The time varies by strength of acid, temperature and pressure as well as the desired depth. Exemplary depths from which the catalyst material has been removed range from 50 microns to 800 microns, alternatively less than 300 microns or less than 200 microns or less than 100 microns. Also, for example, the depth may be at least half of the overall thickness of the diamond body, but the depth is no closer to the interface between the lower side of the diamond body and the upper side of the substrate than about 200 microns. Descriptions of leaching and of leached polycrystalline diamond cutters are contained in, for example, U.S. Pat. No. 4,224,380; U.S. Pat. No. 6,544,308 and U.S. Pat. No. 8,852,546, the entire contents of each are incorporated herein by reference.
The exemplary cutters described and disclosed herein can be incorporated in drilling tools used, for example, in drilling geological formations. Such drilling tools can incorporate flushing media supplied to the drill head to facilitate removing debris from the drilling zone as well as to remove heat from the drill head that is generated in the drilling operation. Examples of drilling tools include drag bits having polycrystalline diamond cutters arranged along a periphery region of a fin or blade.
The exemplary embodiment of a drilling tool comprises a body 2040 including a drill head 2050, a shoulder region 2060, and a shank portion 2070. The drill head 2050, shoulder region 2060 and shank portion 2070 are arranged axially along axis 2030. The shank portion can include an attachment structure, such as a threaded surface or fasteners, to attach the drilling tool 2000 to a drilling apparatus (not shown). The shoulder region 2060 provides a transition area between the drill head 2050 and shank portion 2070.
Mounted along the fin 2010 is a plurality of cutters 2020. At least a portion of the cutters 2020 are of the type disclosed and described herein with a substrate 2080, a diamond body 2090, and a first passage 2100 extending through the cutter 2020 along an axis from a first opening 2110 in the lower side of the substrate to a second opening 2120 in a first side of the diamond body 2090. These details are illustrated on one of the cutters 202) in
In exemplary embodiments, flushing media is supplied to the drill head 2040 via a network of internal channels. The internal channels include a central supply channel 2130 that is open at the shank portion 2070, e.g., for connecting to a supply line from the drilling apparatus, and a plurality of branching channels 2140 that connect the supply channel 2130 to individual outlets. The individual outlets can include the passages 2100 extending through the cutters 2020. Generally, the diameters of the branching channels 2140 are smaller than the diameter of the supply channel 2130, but the relative sizes of the diameters can be adjusted to achieve a desired flow rate of media through network of internal channels. The drilling tool 2000 can be manufactured by casting, for example by using a sand casting or lost-wax method, although machining can also be used to supplement the casting methods, particularly in connection with finish forming of the pockets for the cutters.
In operation, the fluid media, such as cooling fluid, supplied to the drill head 2050 flows through the branching channels 2140 and passages 2100 in the cutters 2020 and exits through the second opening 2120. Debris generated by the drilling action is flushed away from the drill head 2050 by the flow of the fluid media. Additionally, heat generated in the cutters 2020 by the drilling action is transported away from the heat generating regions through the diamond body's contact with a fluid medium in the passage 2100 as well as through the diamond body 2090 itself. In this last regard, the body 2040 of the drilling tool 2000 functions as a heat sink (which is in contact with the cutter 2020 via the braze joint 2150) and heat generated in the cutters is transported through the diamond body 2090 to the heat sink.
While reference has been made to specific embodiments, it is apparent that other embodiments and variations can be devised by others skilled in the art without departing from their spirit and scope. The appended claims are intended to be construed to include all such embodiments and equivalent variations.
Claims
1. A polycrystalline diamond cutter, comprising:
- a substrate including an upper side, a lower side opposite the upper side, and at least one edge side connecting the upper side to the lower side;
- a diamond body including a planar oriented portion and a projecting portion; and
- a first passage extending through the cutter along an axis from a first opening in the lower side of the substrate to a second opening in a first side of the diamond body,
- wherein the planar oriented portion of the diamond body is attached to the upper side of the substrate, and
- wherein the projecting portion of the diamond body forms at least a portion of an inner wall surface of the first passage.
2. The polycrystalline diamond cutter of claim 1, wherein the projecting portion of the diamond body forms the entire inner wall surface of the first passage
3. The polycrystalline diamond cutter according to claim 1, wherein the planar oriented portion of the diamond body has a first side, a second side opposite the first side, and an outer edge side connecting the first side to the second side, and wherein the outer edge side is aligned with the at least one edge side of the substrate.
4. The polycrystalline diamond cutter of claim 3, wherein the outer edge side transforms into a beveled surface.
5. The polycrystalline diamond cutter according to claim 1, wherein the first side of the planar portion forms a right angle with the inner wall of the first passage.
6. The polycrystalline diamond cutter according to claim 1, wherein the first side of the planar portion forms a non-right angle with the inner wall of the first passage.
7. The polycrystalline diamond cutter according to claims claim 1, wherein the first side of the planar portion transforms into the inner wall of the first passage by a curved surface.
8. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of a right cylinder.
9. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of frustum of a cone.
10. The polycrystalline diamond cutter according to claim 1, wherein the first passage has a shape of a one sheet hyperboloid.
11. The polycrystalline diamond cutter according to claim 1, wherein a thickness of the projecting portion varies as a function of axial position.
12-13. (canceled)
14. The polycrystalline diamond cutter according to claim 1, wherein an axial end of the projecting portion that is distal from the planar portion is aligned with the lower side of the substrate.
15. The polycrystalline diamond cutter according to claim 1, wherein an axial length of the projecting portion is less than an axial length of the inner wall of the first passage.
16. The polycrystalline diamond cutter according to claim 1, wherein the second side of the planar oriented portion is attached to the upper side of the substrate.
17. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion is planar.
18. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion is non-planar.
19. The polycrystalline diamond cutter according to claim 16, wherein the second side of the planar oriented portion has a modulated surface texture.
20. The polycrystalline diamond cutter according to claim 1, wherein the first passage extends axially along an axis coincident with a symmetry axis of the cutter and wherein the diamond body is continuous from the radial outer edge side to an axially most distant end of the projecting portion.
21. The polycrystalline diamond cutter according to claim 1, wherein the first passage extends axially along an axis radially offset from a symmetry axis of the cutter
22. The polycrystalline diamond cutter according to claim 21, wherein the diamond body is continuous from the radial outer edge side to an axially most distant end of the projecting portion.
23-42. (canceled)
Type: Application
Filed: Oct 3, 2017
Publication Date: Feb 6, 2020
Inventor: Gary Flood (Canal Winchester, OH)
Application Number: 16/338,822