Polycrystalline Diamond Compact Cutter Having Surface Texturing
A polycrystalline diamond compact cutter for a tool includes a substrate of cemented carbide and a volume of polycrystalline diamond bonded to the substrate. At least one chamfer extends along an outer circumference of the volume of polycrystalline diamond. A textured surface is disposed on at least the at least one chamfer. The textured surface provides a termination point for crack formation, an increased surface area for heat transfer, and decreases chipping of the volume of polycrystalline diamond.
The present disclosure relates to a polycrystalline diamond compact (PCD) cutter having a textured surface for increasing surface area for heat transfer, decreasing chipping or breaking of the cutter and/or providing a termination point for crack formation.
BACKGROUNDAbrasive compacts consist of a mass of diamond or cubic boron nitride particles bonded into a coherent, polycrystalline hard conglomerate. The abrasive particle content of abrasive compacts is high and there is an extensive amount of direct particle-to-particle bonding. Abrasive compacts tend to be brittle and in use they are frequently supported by being bonded to a cemented carbide substrate or support.
Polycrystalline diamond (“PCD”) abrasive compacts are used extensively in cutting, milling, grinding, drilling and other abrasive operations. In some of these applications large forces act on the point or cutting edge and cracks develop in or behind the cutting edge or point. These cracks can propagate through the compact layer.
Cutter performance is limited by the amount of surface area to dissipate heat, as well as friction generated by the chip and coolant flow running across the face of the cutter. Additionally, cutters experience impact damage, resulting in large cracks which propagate through the diamond, leading to large loss of the diamond table.
To limit crack propagation it is known to provide a pattern on the top surface of the diamond table. However, focusing the pattern on the top surface of the cutter does not effectively limit crack propagation or other damage.
Another problem is that in order to effectively limit propagation of cracks and to limit breaking, spalling or chipping, a fairly large amount of diamond volume is required to be removed when forming the pattern along the top surface of the compact. This compromises the abrasion resistance of the cutter.
SUMMARYIn one embodiment a polycrystalline diamond compact cutter for a tool includes a substrate of cemented carbide and a volume of polycrystalline diamond bonded to the substrate. At least one chamfer extends along an outer circumference of the volume of polycrystalline diamond. A textured surface is disposed on at least the at least one chamfer. The textured surface provides a termination point for crack formation, an increased surface area for heat transfer, and decreases chipping of the volume of polycrystalline diamond.
In another embodiment a method for forming a polycrystalline diamond compact cutter includes the steps of providing a cemented carbide substrate and disposing a volume of polycrystalline diamond material on the cemented carbide substrate. The substrate and volume of diamond material are subjected to a high pressure and a high temperature condition to bond the volume of polycrystalline diamond material and substrate. A textured surface is formed on at least at least one chamfer disposed along an outer circumference of the volume of polycrystalline diamond to provide a termination point for crack formation, an increased surface area for heat transfer, and to decrease chipping of the volume of polycrystalline diamond.
In yet another embodiment, a drilling bit includes a cutting element of a volume of polycrystalline diamond. The cutting element includes a cutting edge formed by at least one chamfer extending along an outer circumference of the cutting element. A textured surface is disposed on at least the at least one chamfer to provide a termination point for crack formation, an increased surface area for heat transfer, and decreasing chipping of the volume of polycrystalline diamond. The drill bit includes a substrate of cemented carbide, the cutting element being bonded to the substrate.
In one aspect, having a textured surface with features patterned on the chamfer of the cutter enhances the toughness of a given cutter in an impact damage mode thereby minimizing spalling and chipping at the cutting edge.
In another aspect, the textured surface provides a greater surface area to increase heat transfer at the cutting edge.
In yet another aspect, the textured surface being provided on the chamfer of the cutter limits the amount of diamond removed from the volume allowing the cutter to be leached.
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.
A polycrystalline diamond (“PCD”) cutter may be formed by placing a cemented carbide substrate into the container of a press. A mixture of diamond grains or diamond grains and catalyst binder is placed atop the substrate and compressed under high pressure, high temperature conditions. In so doing, metal binder migrates from the substrate and passes through the diamond grains to promote a sintering of the diamond grains. As a result, the diamond grains become bonded to each other to form the diamond layer, and the diamond layer is subsequently bonded to the substrate. The substrate is often a metal-carbide composite material, such as sintered tungsten carbide (tungsten carbide/cobalt).
As set forth above, PCD compacts are used extensively in cutting, milling, grinding, drilling and other abrasive operations. In some of these applications large forces act on the point or cutting edge and cracks develop in or behind the cutting edge or point. Referring to
As used herein, the articles “a” and “an” are used herein to refer to one or more than one object of the article. By way of example, “an element” means one or more than one element. The term “about” will be understood by persons of ordinary skill in the art to depend on the context in which it is used. As used herein, “about” encompasses variations from ±10% of the reported nominal value. For example, “about 40” is meant to encompass from 36 to 44.
As shown in
PCD volume 14 includes a cutting surface 16 and an outer circumference 18 along which a cutting edge 20 is disposed. A chamfer 24 extends along an outer circumference 18 from cutting edge 20 by an angle, for example 45°. Although only one chamfer is shown it should be appreciated that a plurality of chamfers, either stacked above one another or extending along portions of the outer circumference 18, can be provided. Moreover, chamfer 24 can extend only partially along the height of an outer circumference 18 of the PCD volume.
Cutting surface 16 and chamfer 24 includes a textured surface 30 formed therein. As will be described further herein, textured surface 30 can be applied into a plurality of different patterns by using a laser cutting technique. The laser cutting technique may incorporate a laser having wavelength and power selected to super-heat metal solvent catalyst material that remains in the polycrystalline diamond from the synthesis procedure. The superheating of the solvent metal catalyst may vaporize the solvent metal catalyst, and may carry diamond away, thereby forming a channel in the underlying diamond. The channel generally has a “u-shaped” form having a round bottom at positions generally parallel with the underlying diamond surface into which the channel is formed. The laser cutting technique may also cut diamond through an ablation mechanism. The laser cutting technique may be applied across multiple areas of the diamond, thereby forming a textured surface 30 on the diamond. When evaluated macroscopically, the channel appears as a line that is formed in the exterior surfaces of the diamond. As shown in
As shown in
Radial lines 34 and radial circles 36 can have a depth of about 10 μm to about 0.1 mm and a width of about 0.002″ (inches) to about 0.004″ (inches). Radial lines 34 are spaced at about 4 degrees. Radial circles 36 are spaced at about 0.020″ from one another. The PCD volume 14 has a nominal outer diameter of 16 mm.
As shown in
Referring to
Referring to
It should be appreciated that radial lines are not limited to straight or smooth lines. Wavy, or irregular lines may also assist with heat dissipation.
As shown in
Pattern 40 can be a repeat of pattern sections 44, for example, from about 3 (as shown) to about 5 sections disposed about the periphery portion 28. Accordingly, the cutter may have a plurality of areas such that when one section 44 is worn, the cutter can be rotated to another section in which the pattern 40 repeats, and the cutter may be run again, presenting equivalent textured surfaces for the material removal operation.
Referring to
The radial lines can be spaced from about 0.01″ to about 0.02″ apart from one another. The spacing between the radial lines determines how aggressively the cutter engages the rock or other material being drilled. As can be seen from
Referring to
The PCD cutters of the present disclosure can be formed by providing a cemented carbide substrate, disposing a volume of polycrystalline diamond material on the cemented carbide substrate and subjecting the substrate and volume of diamond material to a high pressure and a high temperature condition to bond the volume of diamond material and substrate.
The textured surface is formed by laser cutting. The compact is placed in a laser cutting machine and aligned properly so that the CAD-driven laser cuts the pattern appropriately. The pattern of the textured surface can be applied to a desired portion of the PCD volume. However, the textured surface if formed on at least a chamfer disposed along an outer circumference of the volume of polycrystalline diamond to provide a termination point for crack propagation and to decrease chipping of the volume of polycrystalline diamond. As set forth below, when a crack does occur it may run along the pre-cut line of the textured surface in the chamfer and terminate before the crack grows into the cutting surface, thereby preserving the structural integrity of the surrounding portions of the cutter.
As set forth above, the textured surface can have a variety of patterns. The more patterns/lines cut into the PCD volume the greater the surface area and increased heat transfer and more cutting edges.
After the textured surface is applied to the PCD volume the cutter can be finished, for example, leached, cleaned or machined.
Another feature of the PCD cutter of the present disclosure is that leaching to remove retained metal solvent catalyst that remains in the diamond from the synthesis process is improved due to the positioning of the radial lines of the pattern and volume removal. It is believed that it is not feasible to leach a cutter that has been cut deeply. Such cutters that are deeply cut may expose the carbide to the leaching acid, thereby impairing the structural integrity of the cutter. The PCD cutter of the present disclosure having cuts that extend a distance less than the thickness of the diamond will still allow the cutter to be leachable. Referring again to
Additionally, less volume of diamond is removed while still benefiting from the crack arresting features.
ExampleLaboratory tests of cutter performance were conducted using a series of instrumentation. Frontal impact testing was performed to observe crack propagation in a surface textured and a conventional, untextured cutter. In this test, cutters are mounted to a dead-weight drop system at an inclined angle, and dropped against a hard work piece, such as a hardened steel block, tungsten carbide block, or volume of sintered diamond. Cutters are dropped from various heights to control the energy of impact. Testing was also performed in an interrupted milling of rock. Cutters are mounted on a fly wheel and rotated at high speed as a slab of rock is feed into the rotating path of the cutter. In this work, the rock used was barre granite. As the cutter rubs across the face of the rock without coolant, rapid heating of the cutter occurs, leading to accelerated thermal breakdown of the PCD cutter.
Referring to Table 1 below although the pattern of the textured surface acts as a crack arrestor, see
1. A polycrystalline diamond cutter for a tool, comprising:
a substrate of cemented carbide;
a volume of polycrystalline diamond bonded to said substrate;
at least one chamfer extending along an outer circumference of the volume of polycrystalline diamond; and
a textured surface disposed on at least the at least one chamfer, wherein the textured surface has at least about 60% diamond along the at least one chamfer, and the textured surface provides a termination point for crack formation, an increased surface area for heat transfer, and decreasing chipping of the volume of polycrystalline diamond.
2. The polycrystalline diamond cutter of item 1, wherein the textured surface is a pattern formed in the volume of polycrystalline diamond.
3. The polycrystalline diamond cutter of items 1 or 2, wherein the textured surface is disposed only on the at least one chamfer.
4. The polycrystalline diamond cutter of any one of the above items, wherein the volume of polycrystalline diamond includes a cutting surface having a periphery portion, the textured surface being disposed on the periphery portion and the at least one chamfer.
5. The polycrystalline diamond cutter of any one of the above items, wherein the periphery portion is about 20% of an area of the cutting surface.
6. The polycrystalline diamond cutter of any one of the above items, wherein the pattern is a grid formed by a plurality of intersecting radial lines and radial circles.
7. The polycrystalline diamond cutter of any one of the above items, wherein the pattern is a plurality of radial lines.
8. The polycrystalline diamond cutter of any one of the above items, wherein the pattern is a plurality of radial circles.
9. The polycrystalline diamond cutter any one of items 6-8, wherein each of the radial circles and/or each of the radial lines has a depth of about 10 μm to about 0.1 mm and a width of about 0.002″ to about 0.004″.
10. The polycrystalline diamond cutter of any one of the above items, wherein the pattern is formed by a plurality of different intersecting patterns.
11. The polycrystalline diamond cutter of any one of the above items, wherein the pattern is a formed by a plurality of pattern sections extending along the periphery portion and at least one chamfer.
12. The polycrystalline diamond cutter of any of the above items, wherein spacing between at least two adjacent radial lines is in a range from about 2 degrees to about 6 degrees.
13. The polycrystalline diamond cutter of any of the above items, wherein spacing between at least two adjacent radial lines is in a range from about 3.6 degrees to about 4.4 degrees.
14. A method for forming a polycrystalline diamond cutter, comprising the steps of:
providing a cemented carbide substrate;
disposing a volume of polycrystalline diamond material on the cemented carbide substrate;
subjecting said substrate and volume of diamond material to a high pressure and a high temperature condition to bond said volume of diamond material and substrate; and
forming a textured surface on at least at least one chamfer disposed along an outer circumference of the volume of polycrystalline diamond, wherein the textured surface has at least about 60% diamond along the at least one chamfer, and the textured surface providing a termination point for crack formation, an increased surface area for heat transfer, and to decrease chipping of the volume of polycrystalline diamond.
15. The method of item 14, wherein the textured surface is a pattern formed in the volume of polycrystalline diamond.
16. The method of items 14 or 15, wherein the textured surface is formed only on the at least one chamfer.
17. The method of any one of items 14-16, wherein the volume of polycrystalline diamond includes a cutting surface having a periphery portion, the textured surface being disposed on the periphery portion and the at least one chamfer.
18. The method of any one of items 14-17, wherein the periphery portion is about 20% of an area of the cutting surface.
19. The method of any one of items 14-18, wherein the pattern is a grid formed by a plurality of intersecting radial lines and radial circles.
20. The method of any one of items 14-19, wherein the pattern is a plurality of radial lines.
21. The method of any one of items 14-20, wherein the pattern is a plurality of radial circles.
22. The method of any one of items 19-21, wherein each of the radial circles and/or each of the radial lines has a depth of about 10 μm to about 0.1 mm and a width of about 0.002″ to about 0.004″.
23. The method of any one of items 14-22, wherein the pattern is formed by a plurality of different intersecting patterns.
24. The method of any one of items 14-23, wherein the pattern is a formed by a plurality of pattern sections extending along the periphery portion and at least one chamfer.
25. The method of any one of items 14-24, further comprising the step of leaching the volume of polycrystalline diamond.
26. The method of any one of items 14-25, wherein spacing between at least two adjacent radial lines is in a range from about 2 degrees to about 6 degrees.
Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.
Claims
1. A polycrystalline diamond cutter for a tool, comprising:
- a substrate of cemented carbide;
- a volume of polycrystalline diamond bonded to said substrate;
- at least one chamfer extending along an outer circumference of the volume of polycrystalline diamond; and
- a textured surface disposed on at least the at least one chamfer, the textured surface having at least two adjacent repeating elements that are spaced apart about 6 degrees or less from one another, the textured surface providing a termination point for crack formation and decreasing chipping of the volume of polycrystalline diamond.
2. The polycrystalline diamond cutter of claim 1, wherein the textured surface has at least three adjacent repeating elements, the outside adjacent repeating elements are each spaced apart about 6 degrees or less from an inside adjacent repeating element.
3. The polycrystalline diamond cutter of claim 1, wherein the textured surface is a pattern formed in the volume of polycrystalline diamond.
4. The polycrystalline diamond cutter of claim 1, wherein the textured surface is disposed only on the at least one chamfer.
5. The polycrystalline diamond cutter of claim 3, wherein the volume of polycrystalline diamond includes a cutting surface having a periphery portion, the textured surface being disposed on the periphery portion and the at least one chamfer.
6. The polycrystalline diamond cutter of claim 4, wherein the periphery portion is about 20% of an area the cutting surface.
7. The polycrystalline diamond cutter of claim 3, wherein the pattern is a grid formed by a plurality of intersecting radial lines and radial circles.
8. The polycrystalline diamond cutter of claim 5, wherein each of the radial lines and radial circles has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
9. The polycrystalline diamond cutter of claim 3, wherein the pattern is a plurality of radial lines.
10. The polycrystalline diamond cutter of claim 9, wherein each of the radial lines has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
11. The polycrystalline diamond cutter of claim 9, wherein spacing between at least two adjacent radial lines is in a range from about 2 degrees to about 6 degrees.
12. The polycrystalline diamond cutter of claim 3, wherein the pattern is a plurality of radial circles.
13. The polycrystalline diamond cutter of claim 12, wherein each of the radial circles has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
14. The polycrystalline diamond cutter of claim 3, wherein the pattern is formed by a plurality of different intersecting patterns.
15. A method for forming a polycrystalline diamond cutter, comprising the steps of:
- providing a cemented carbide substrate;
- disposing a volume of polycrystalline diamond material on the cemented carbide substrate;
- subjecting said substrate and volume of diamond material to a high pressure and a high temperature condition to bond said volume of diamond material and substrate; and
- forming a textured surface on at least at least one chamfer disposed along an outer circumference of the volume of polycrystalline diamond, the textured surface having at least two adjacent repeating elements that are spaced apart about 6 degrees or less from one another, the textured surface providing a termination point for crack formation and decreasing chipping of the volume of polycrystalline diamond.
16. The method of claim 15, wherein the textured surface has at least three adjacent repeating elements, the outside adjacent repeating elements are each spaced apart about 6 degrees or less from an inside adjacent repeating element.
17. The method of claim 15, wherein the textured surface is a pattern formed in the volume of polycrystalline diamond.
18. The method of claim 17, wherein the textured surface is formed only on the at least one chamfer.
19. The method of claim 17, wherein the volume of polycrystalline diamond includes a cutting surface having a periphery portion, the textured surface being disposed on the periphery portion and the at least one chamfer.
20. The method of claim 19, wherein the periphery portion is about 20% of an area of the cutting surface.
21. The method of claim 17, wherein the pattern is a grid formed by a plurality of intersecting radial lines and radial circles.
22. The method of claim 21, wherein each of the radial lines and radial circles has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
23. The method of claim 17, wherein the pattern is a plurality of radial lines.
24. The method of claim 23, wherein each of the radial lines has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
25. The method of claim 23, wherein spacing between at least two adjacent radial lines is in a range from about 2 degrees to about 6 degrees.
26. The method of claim 17, wherein the pattern is a plurality of radial circles.
27. The method of claim 26, wherein each of the radial circles has a depth of about 10 μm to about 0.1 mm from the underlying polycrystalline diamond and a width of about 0.002 inches to about 0.004 inches.
28. The method of claim 17, wherein the pattern is formed by a plurality of different intersecting patterns.
29. The method of claim 15, further comprising the step of leaching the volume of polycrystalline diamond.
30. A drilling bit comprising:
- a cutting element of a volume of polycrystalline diamond, the cutting element including a cutting edge formed by at least one chamfer extending along an outer circumference of the cutting element, a textured surface disposed on at least the at least one chamfer, the textured surface having at least about 60% diamond along the at least one chamfer, the textured surface providing a termination point for crack formation and decreasing chipping of the volume of polycrystalline diamond, and the textured surface has at least three adjacent repeating elements, the outside adjacent repeating elements are each spaced apart about 6 degrees or less from an inside adjacent repeating element; and
- a substrate of cemented carbide, the cutting element being bonded to the substrate.
Type: Application
Filed: Sep 14, 2015
Publication Date: Oct 12, 2017
Inventor: Andrew GLEDHILL (Westerville, OH)
Application Number: 15/510,547