US20140231151A1

US20140231151A1 - Optimum powder placement in polycrystalline diamond cutters

Info

Publication number: US20140231151A1
Application number: US14/165,355
Authority: US
Inventors: Terry Richard Matthias; Mark Francis; Simon Brown; Kevin Emery; Paul Ellis; Michael Scott Nixon
Original assignee: National Oilwell Varco LP
Current assignee: National Oilwell Varco LP
Priority date: 2013-01-28
Filing date: 2014-01-27
Publication date: 2014-08-21

Abstract

A precise and reproducible method of making a cutter element for a cutting tool includes positioning at least a first material layer of powder; a substrate and sintering. Whereby the positioning is performed by a fill to weight system, and comprises depositing the first material at a rate of about 1 mg per second to about 300 mg per second by the automated system.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/757,322 filed Jan. 28, 2013, which is incorporated herein by reference in its entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

BACKGROUND

1. Field of Endeavor
This disclosure relates generally to polycrystalline diamond compacts in all its manufacture and uses. This disclosure relates further to the use of polycrystalline diamond compacts in cutting tools such as earth-boring drill bits used to drill a borehole for the ultimate recovery of oil, gas, or minerals. More particularly, the disclosure relates to polycrystalline diamond compact cutter elements with improved wear resistance and toughness, and methods of powder placement for manufacturing cutter elements and cutting tools employing such cutter elements.
2. Background Technology
An earth-boring drill bit is typically mounted on the lower end of a drill string and is rotated by rotating the drill string at the surface or by actuation of downhole motors or turbines, or by both methods. With weight applied to the drill string, the rotating drill bit engages the earthen formation and proceeds to form a borehole along a predetermined path toward a target zone. The borehole thus created will have a diameter generally equal to the diameter or “gage” of the drill bit.
The cost of drilling a borehole for recovery of hydrocarbons is very high, and is proportional to the length of time it takes to drill to the desired depth and location. The time required to drill the well, in turn, is greatly affected by the number of times the drill bit must be changed before reaching the targeted formation. This is the case because each time the bit is changed, the entire string of drill pipe, which may be miles long, must be retrieved from the borehole, section by section. Once the drill string has been retrieved and the new bit installed, the bit must be lowered to the bottom of the borehole on the drill string, which again must be constructed section by section. As is thus obvious, this process, known as a “trip” of the drill string, requires considerable time, effort and expense. Accordingly, it is desirable to employ drill bits which will drill faster and longer, and which are usable over a wider range of formation hardness. The length of time that a drill bit may be employed before it must be changed depends upon a variety of factors. These factors include the bit's rate of penetration (“ROP”), as well as its durability or ability to maintain a high or acceptable ROP. In turn, ROP and durability are dependent upon the cutter elements' abrasion resistance, toughness and ability to resist thermal degradation. Many different types of drill bits and cutting structures for bits have been developed. Two predominant types of drill bits are roller cone bits and fixed cutter bits, also known as rotary drag bits. A common roller cone bit has three rotating cones, each of which rotates on its own axis during drilling. Roller cone bits comprise either tungsten carbide inserts (TCI) or milled tooth (MT). The bit body may be machined from solid metal, or may alternatively be molded using a powder metallurgy process in which a tungsten carbide powder is infiltrated with a metal alloy binder in a furnace so as to form a hard matrix.
Typically, the cutters each take the form of a tablet of superhard material (such as polycrystalline diamond) bonded to a substrate, for example of tungsten carbide. Each cutter is typically of circular or part-circular shape.
In some drill bits, the cutters are arranged upon the blades at different radial distances to one another so that the cutters sweep over the full area of the bottom of the wellbore. However, there is a tendency for drill bits of this type to be of relatively low stability. While the bits are fixed to the drilling rigs, the rotation of the drill pipe will be in a clockwise direction and the roller cones are rotated in an anti-clockwise direction. Each roller cone is rotated on its own axis with the help of a bearing. The selection of cutting structure of the roller cone bits varies according to the rock formation. There are three main categories: soft, medium and hard formation bits. Soft formation rock bits are used in unconsolidated sands, clays, soft lime stones, red beds and shale. Medium formation bits are used in calcites, dolomites, lime stones, and hard shale, while hard formation bits are used in hard shale, calcites, mudstones, cherty lime stones and hard and abrasive formations. Soft bits (used in soft formations) will have longer protruding teeth or chisel-shaped buttons (cutting elements), and fewer, more widely arranged teeth. Medium formation bits will have much closer teeth than soft formation bits, and the protrusion of the teeth is reduced. The teeth are very short and closely arranged on hard formation bits. Because of the shorter teeth the penetration of the rock bit during drilling is less than with soft or medium formation bits, but the other bits cannot be used in hard strata.
A common fixed cutter bit has a plurality of blades angularly spaced about the bit face. The blades generally project radially outward along the bit body and form flow channels there between. Cutter elements are typically mounted on the blades, as well as other surfaces of the bit.
PDC Cutter Elements:
Attempts are made to optimize cutter elements for drilling effectively in specific geological formations. For this reason, cutter elements may be comprised of a number of materials that impart specific properties to the finished cutter elements.
For convenience, as used herein, reference to “PDC bit” or “PDC cutter element,” “PDC compact” or “PDC cutters” refers to a fixed cutter bit or cutting element employing a hard cutting layer that contains polycrystalline diamond (PDC refers to Polycrystalline Diamond Compact). Polycrystalline diamond elements may also be formed into other shapes suitable for applications such as on roller cone bit PDC inserts, hollow dies, wire drawing dies, heat sinks, cutting tools, friction bearings, valve surfaces, indentors, and tool mandrels.
In a typical fixed cutter bit, each cutter element comprises an elongate and generally cylindrical support member, which is received and secured in a pocket formed in the surface of one of the several blades.
Each cutter element typically has a hard cutting layer of polycrystalline diamond or other super-abrasive material such as cubic boron nitride, thermally stable diamond, chemically modified or doped diamond, polycrystalline cubic boron nitride, or ultra-hard tungsten carbide (meaning a tungsten carbide material having a wear-resistance that is greater than the wear-resistance of the material forming the substrate) as well as mixtures or combinations of these materials. The polycrystalline diamond layer is coupled to a substrate material such as a metal carbide (such as WC) containing a metal catalyst (such as cobalt Co). During manufacture, the diamond powder and the metal carbide/catalyst are subjected to high pressure and high temperature to sinter and form the PDC compact structure.
Powder Packing
Higher powder packing density is used to achieve increased wear resistance and strength in PDC cutters, whereby the grain size and/or powder packing density may be varied in layers within a cutter element to impart different wear resistance throughout the diamond table. Typically, the wear resistance of the polycrystalline diamond increases with the packing density of the diamond particles and the degree of inter-particle bonding. It is known in the prior art (such as in U.S. Pat. No. 7,665,898) that the method used for loading diamond powders into a canister for subsequent sintering has a number of effects on the general shape and tolerances of the final part. In particular, the packing density of the feedstock diamond throughout the canister should be as uniform as possible in order to produce good quality sintered polycrystalline diamond compact structure. The degree of uniformity in the density of the powdered material after loading will affect the geometry and uniformity of wear properties and toughness of the polycrystalline diamond cutting element.
Powder Properties
The properties of the selected diamond powder(s) will also affect the characteristics of the finished PDC cutter. Typically, the powder may be mono or multimodal, having a uniform particle size; or a gradient of particle sizes; and the chemistry of the diamond particles may also be pre-selected.
The size and coarseness of diamond powders used in high pressure high temperature manufacture of a PDC cutter also affects the properties of the finished cutter. During the sintering process, diamond particles, under pressure move relative to each other, fragment, and increase the powder apparent density. Coarse powders will display a higher degree of crushing than a finer one, as the average number of contact points per unit volume is much higher for fine powders, and therefore fine powders display a lower contact stress and lower probability for fragmentation.
The diamond powder is typically packed against the WC-Co substrate, which is the origin of the catalyst metal (e.g., Co) that induces sintering. When the cobalt reaches its melting point, it is forced into the open porosities left within the layer of compacted powder. Sintering takes place through carbon dissolution and precipitation and reduction of internal energy. Densification is determined by the pressure and by the contact area relative to the cross-sectional area of the particles. The reaction speed is proportional to the temperature and to the average effective pressure, which is the actual contact pressure between particles. The sintering process is therefore faster if both the contact pressure and the temperature are increased.
The smaller the size of the diamond crystals sintered together, the higher the wear or abrasion resistance, but the lower the impact strength of the resulting PDC. With larger diamond particle sizes, a lower abrasion resistance is observed, but an increased toughness and impact resistance is achieved.
Thermal Stability
The PDC elements produced by the methods described above, comprise a continuous matrix of diamond, wherein diamond particles are directly bonded to other diamond particles through diamond-to-diamond bonds. Additionally, there is a continuous matrix of interstices containing the catalyzing material (typically cobalt). The formation of the matrix of diamond-to-diamond bonds and the interstices of catalyzing material largely contribute to the mechanical properties of the PDC cutter. Typically, the diamond table constitutes 85% to 95% by volume of the hard layer, and the catalyzing material the other 5% to 15%.
Typical PDC compacts have limited heat resistance and experience high thermal wear. At atmospheric pressure, a diamond's surface turns to graphite at 900° C. or higher. In a vacuum or in inert gas, diamond does not graphitize easily, even at 1,400° C. However during use, conventional PDC cutters experience a decline in cutting performance around 750° C., a temperature which the cutting edge can easily reach in service due to frictional heating in hard, abrasive rock. Flash temperatures which are extremely high localized temperatures at the microscopic level can be much higher, exceeding the melting temperature of cobalt (1,495° C.).
The presence of interstitial cobalt catalyzing material is therefore believed to be the reason that PDC converts to graphite at a lower temperature than simple diamond. As temperatures increase, graphitization of the diamond in the presence of cobalt becomes a dominant effect. Diamond wear is then due to an allotropic transformation into graphite or amorphous carbon under the influence of localized frictional heating.
This transformation is accelerated in the presence of cobalt through a combination of mechanical and chemical effects. For example, the shear resistance of the cobalt drops rapidly, and the diamond grains are not strongly held, leading to additional damage to the surface. It is also known that the real area of contact depends on the velocity with which plastic strains are propagated in the metal binder. The shearing occurs so rapidly that full plastic yielding under the normal load is not possible.
There is also a significant difference between the thermal expansion coefficients of cobalt and diamond. During heating, cobalt expands at a higher rate than diamond, leading to increased thermal stress in the diamond table, causing the structure to break down. The cobalt between the diamond crystals expands and breaks the diamond-to-diamond bonds. Such expansions are also observed between the substrate and the diamond layer.
PDC cutting elements become extremely hot during drilling. However it is known that the temperature at a distance of a few microns from the contact point is about 95% of the (absolute) temperature at the point of contact. Since the temperature decreases very rapidly with increasing distance from the shearing zone (about 400 K/mm), the cutting tip behaves like a thin film of low shear strength, supported by a hard substrate.
The ability to provide desirable properties for the final PDC cutter element by choosing the appropriate diamond for each layer is not limited to the size of the diamond grain, but also the chemical diversity of the diamond, or combinations thereof. Properties that can be controlled by modifying the chemical content of the diamond include, for example: electrical conductivity, strength, optical properties and thermal stability. For example a cutter element may be composed of a diamond powder comprising a dopant such as: Al, B, N, Li, K, Ti, P, and Zr, or combinations thereof. Boron doped diamonds can also be used as super-abrasive particles and are potentially superior in terms of thermal stability compared to non-boron doped diamonds. Boron has P-type semi-conductive properties, whereby its valence electron deficiency allows boron to accept electrons creating “positive holes” in the lattice, while Phosphorus (P) doped diamond has N-type semi-conductive properties. Therefore, some PDC cutters can be designed to have increased conductivity and increased thermal stability in comparison to non-boron doped PDC cutter elements.
Leaching
Means of improving PDC heat resistance are known, such as by immersing, the PDC table in acid and heat treating the table. The acid treatment dissolves the metal binder phase in the polycrystalline diamond. This process creates a thermally stable polycrystalline (TSP) that withstands temperatures of up to 1,200° C. However, with the cobalt phase removed, cavities (empty interstices) result in the TSP, degrading the strength of the final sintered material. The result is a material that lacks sufficient hardness and impact strength to be used as a cutting tool, as without the cobalt phase, it is difficult to create a strong bond between the TSP and the substrate material.
In a process generally referred to as leaching, PDC materials are engineered to resolve the temperature deficiencies of conventional PDC material but without reducing the mechanical strength of the PDC, and without creating attachment deficiencies as seen in the TSP examples. After producing the PDC by conventional methods, its cutting surfaces are exposed to powerful highly concentrated acids, such as nitric, sulfuric and/or hydrofluoric, raised to near the boiling points of such acids. The PDC cutters are placed in a bath of the acid, or mixtures of such acids, which removes the cobalt phase typically from the entire diamond table in the acid etching process.
Leaching typically occurs to a predefined depth (details of which are provided in U.S. Pat. Nos. 6,739,214, 6,592,985, 6,749,033, 6,797,326, 6,562,462, 6,585,064 and 6,589,640). The depth of the acid leaching process is a function of many factors, including: the nature of the metallic phase; this will often involve cobalt, but other known metallic components can be used; the diamond crystal size, typically finer crystals have smaller interstitial spaces between the crystals, resulting in a smaller amount of cobalt to be leached out; the chemical composition of the acid used in the leaching process, i.e. some acids are stronger than others and the volumetric ratio of one acid to another acid (if mixtures are used) also affects the aggression of the acids used in the leaching process; the temperature of the acid used, the acids used are more aggressive when used at or near their respective boiling points; and the time of exposure of the metallic phase to the leaching acid.
Cobalt is typically removed up to about 450 microns deep into the polycrystalline diamond. Leaching a thin layer at the working surface dramatically reduces diamond degradation and improves the cutter element's thermal resistance. Because cobalt is present within the remainder of the PDC diamond table, there is less loss of overall strength in the sintered object than in TSP. Also, because there are few void interstices, thermal conductivity is not impaired in the diamond table, and the heat that is generated at the tip of the cutter element is effectively dispersed.
Despite the significant advances provided by leaching, it can be somewhat difficult to control the depth of leaching of the PDC layer, whereby the acid is prone to sweep further into the polycrystalline diamond matrix than intended. Barrier methods are therefore often used to control over-leaching of the PDC element
PDC cutters have been designed where the diamond table has been composed of multimodal diamond grit or of different PDC table geometries. For example U.S. Pat. No. 7,712,553 recognizes that in abrasive rock formations, full face leached cutters also wear, and the wear flat is usually large enough that the PDC cannot be rotated. This results in the cutter being essentially useless once worn, even though it has an expensive leaching treatment across the entire diamond table. Thus resulting in portions of each cutter that are never used due to large wear flat development. The prior art further contemplates that only a selected portion or portions of the PDC cutter needs to be leached. Such leached/non-leached patterns are produced by covering the PDC cutter with Teflon™ and treating the exposed, uncovered areas with acid. Such a method is therefore limited by the precision by which the Teflon can be placed and removed.
Further, U.S. Pat. No. 6,585,064 discloses that it may be beneficial in some circumstances to have a differential wear rate in a PDC cutter, where the edges of the cutter wear at a greater rate than the center of the cutter such that, in service, the cutter retains a characteristic curved shape rather than becoming a flattened surface. Such a cutter is manufactured by placing diamond powder that is non-leachable to form the softer edges of the cutter, while the center of the cutter is composed of a leachable and resultantly more abrasive/thermally resistant diamond. Powder deposition in the prior art is typically performed manually and hence is slow; has limited accuracy in the weight of powder deposited; has limited reproducibility, and can achieve limited geometric or pattern complexity.
Residual Stresses
Residual stresses in PDC cutters arise from the difference in thermal expansion between PDC layers and the supporting tungsten carbide substrate after sintering at high pressure and temperature. PDC is sintered under conditions (1500-2000 C and 50 to 70 kbar), where diamond is the thermodynamically stable phase of carbon, and where metal catalysts enhance the diamond-to-diamond bonding kinetics. As described above, the individual diamond crystals/particles bond together and to the substrate under these extreme pressure and temperature conditions.
As pressure is released and the PDC is allowed to cool, the diamond layer and substrate material respond at different rates, giving rise to residual stresses in the PDC. As the substrate contracts, it tries to pull the diamond table with it. The diamond layers on the outer diameter of the cylindrical PDC cutter are strongly pulled downward by the retracting carbide. At the same time, they are being pulled upward by the diamond table as the diamond table contracts at a slower rate than the substrate, thereby creating the high tensile stress at the diamond edge. The direction of this tensile stress is nearly vertical, and correlates with observed cracks and fracturing typically seen after a cutter element undergoes side impact loading.
The subsequent fractures propagate roughly parallel to the diamond-substrate interface, delaminating the entire diamond table. Tensile stresses exist on almost the entire diamond table surface in PDC cutters. Such tensile stresses decrease the ability of the cutter to sustain high loads before fracture. Hence these residual stresses can significantly reduce the toughness and impact resistance of the cutters, often resulting in catastrophic diamond-table loss or delamination, especially as the diamond-layer thickness increases. Creating non-planer interfaces between the substrate and the diamond table reduces the tensile stresses experienced relative to a planar interface. Such geometries are thought to counteract the downward pull on the outer diamond layers, reducing the residual stresses, thereby reducing chipping, spalling and diamond table delamination.
The study of differential wear and damage to used bits and cutter elements has demonstrated the need to improve, for example, PDC diamond formulations, chemical properties, thermal stability, and mechanical strength, with the overall goal of imparting improved impact and abrasion resistance to the PDC cutter element. Despite advances in these areas, there remains a need in the art for a reliable and reproducible method of producing a cutting structure with improved impact and abrasion resistance.

BRIEF SUMMARY OF THE DISCOSED EMBODIMENTS

In a first exemplary embodiment of the invention, a method of making a cutter element for a cutting tool comprises positioning at least a first material layer of powder in a container; positioning a second material layer adjacent to said at least a first material layer, to form a non-planer interface between the first and second material layer, where the positioning is performed by a fill to weight system, and comprises depositing the first material layer and the second material layer at a rate of about 1 mg per second to about 300 mg per second; loading a substrate in the container; and sintering to form a cutter element.
In some embodiments of the method of making a cutter element the first material layer comprises diamond, wherein the diamond may be a diamond powder; and the second material layer comprises metal carbide. In another embodiment of the method of making a cutter element the first material layer comprises metal carbide, and in a further embodiment of the method of making a cutter element the metal carbide is removed to form a non-planer cutter surface.
In one embodiment of the method of making a cutter element, said positioning optimizes packing density between said material and said substrate, forming a uniform interface between said material and said substrate. In another embodiment the method of making a cutter element further comprises positioning a second material in the container adjacent to said first material; and after sintering, eroding one of said first and second materials. In another embodiment, said positioning of said first material comprises positioning about 1 mg to about 1700 mg.
In an exemplary embodiment, a cutter element is provided wherein the cutter element comprises a substrate; and at least a first material layer, wherein said element is made by positioning at least a first material layer of powder in a container; positioning a second material layer adjacent to said at least a first material layer, to form a non-planer interface between the first and second material layer, where the positioning is performed by a fill to weight system, and comprises depositing the first material layer and the second material layer at a rate of about 1 mg per second to about 300 mg per second; loading a substrate in the container; and sintering to form a cutter element. In another embodiment of the cutter element said first material is coupled to the substrate through a non-planer interface, a further embodiment comprises a second material layer, wherein the second layer is coupled to the first layer through a non-planer interface; in a still further embodiment the second material layer comprises metal carbide.
In another embodiment the cutter element further comprising an erodible material layer, wherein the erodible material layer is coupled to the first material layer through a non-planer interface, in a further embodiment the erodible material comprises the cutting face of the cutter element, and in a further embodiment the erodible material comprises metal carbide. In another embodiment, the cutter element further comprises an erodible material layer forming at least a portion of the cutting face of the cutter element. In a further embodiment, the cutter element further comprising a polycrystalline diamond layer in the central portion of the cutting face, said erodible material surrounding said polycrystalline diamond material on the cutting face.
In an embodiment of the cutter element, the first material possesses mono-modal properties, multi-modal properties or combinations thereof, wherein said properties comprise physical composition, chemical composition or combinations thereof. In some embodiments said physical composition comprises, particle size, particle shape, density, thermal conductivity, porosity or combinations thereof. In further embodiments chemical composition comprises doped diamond or un-doped diamond.
In a further embodiment, the cutter element further comprising a second material, wherein said second material layer comprises polycrystalline diamond and said first layer is an erodible material, wherein said erodible material comprises a region of the cutting face of said element. In a further still embodiment, said region is concaved, and in another embodiment said region comprises perimeter of the cutting face.

BRIEF DESCRIPTION OF THE DRAWINGS

For a detailed description of the disclosed embodiments, reference will now be made to the accompanying drawings, wherein:

FIG. 1 is a perspective view of an embodiment of a fixed cutter bit made in accordance with principles described herein;

FIG. 1( b) is a perspective view of an embodiment of a roller cone bit made in accordance with principles described herein;

FIG. 2 is a top view of the bit shown in FIG. 1;

FIG. 3 is a partial cross-sectional view of the bit shown in FIG. 1 with the blades and the cutting faces of the cutter elements rotated into a single composite profile;

FIGS. 4A and 4B are top and side views, respectively, of an exemplary PDC cutter element made in accordance with principles described herein;

FIGS. 4C and 4D are side views of an exemplary PDC cutter elements used for example with a roller cone bit made in accordance with principles described herein;

FIG. 5A depicts a process flow chart representing a method for three dimensionally placing of various materials, such as diamond powders and a substrate, to form a PDC cutter element, in accordance with principles described herein;

FIG. 5B depicts a rendering of fill to weight delivery heads; in accordance with principles described herein;

FIG. 5C depicts a rendering of a plot of the deposition (F) of powders (A) and (B) with time by the fill to weight delivery heads of FIG. 5B;

FIG. 6A is a depiction of an exemplary pre-formed substrate being loaded into a canister containing pre-deposited carbide powder deposited upon and forming a non-planer interface with diamond powder; made in accordance with principles described herein;

FIG. 6B is a depiction of an exemplary pre-formed substrate being loaded into a canister containing pre-deposited diamond powder deposited upon and forming a non-planer interface with an erodible powder; made in accordance with principles described herein;

FIGS. 7A and 7B are exemplary cross-sectional views of embodiments of a PDC cutters comprising regions of erodible and abrasion resistant diamond powders positioned on a substrate, made in accordance with principles described herein;

FIG. 8A and FIG. 8B show conventional methods of packing the components of a PDC cutter element into a canister for sintering;

FIG. 8C is an exemplary embodiment of a method of packing the components of a PDC cutter element into a canister for sintering; in accordance with principles described herein.

FIGS. 9A and 9B are exemplary embodiments of PDC cutter elements formed by positioning different layers of mixes of diamond powders, made in accordance with principles described herein.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

The following discussion is directed to various exemplary embodiments. However, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and that the scope of this disclosure, including the claims, is not limited to that embodiment.
The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may be omitted in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct engagement between the two devices, or through an indirect connection via other intermediate devices and connections. As used herein, the term “about,” when used in conjunction with a percentage or other numerical amount, means plus or minus 10% of that percentage or other numerical amount. For example, the term “about 80%,” would encompass 80% plus or minus 8%.
Referring to FIGS. 1(A) and 2, exemplary drill bit 10 is a fixed cutter PDC bit adapted for drilling through formations of rock to form a borehole. Bit 10 generally includes a bit body 12, a shank 13 and a threaded connection or pin 14 for connecting bit 10 to a drill string (not shown), which is employed to rotate the bit in order to drill the borehole. Bit face 20 supports a cutting structure 15 and is formed on the end of the bit 10 that faces the formation and is generally opposite pin end 16. Bit 10 further includes a central axis 11 about which bit 10 rotates in the cutting direction represented by arrow 18. As used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., bit axis 11), while the terms “radial” and “radially” generally mean perpendicular to the axis. For instance, an axial distance refers to a distance measured along or parallel to a given axis, and a radial distance refers to a distance measured perpendicular to the axis.
Body 12 may be formed in a conventional manner using powdered metal tungsten carbide particles in a binder material to form a hard metal cast matrix. Alternatively, the body can be machined from a metal block, such as steel.
As best seen in FIG. 3, body 12 includes a central longitudinal bore 17 permitting drilling fluid to flow from the drill string into bit 10. Body 12 is also provided with downwardly extending flow passages 21 having ports or nozzles 22 disposed at their lowermost ends. The flow passages 21 are in fluid communication with central bore 17. Together, passages 21 and nozzles 22 serve to distribute drilling fluids around cutting structure 15 to flush away formation cuttings during drilling and to remove heat from bit 10.
Referring again to FIGS. 1(A) and 2, cutting structure 15 is provided on face 20 of bit 10 and includes a plurality of blades which extend from bit face 20. In the embodiment illustrated in FIGS. 1(A) and 2, cutting structure 15 includes six blades 31, 32, 33, 34, 35, and 36, with the blades integrally formed as part of, and extending from, bit body 12 and bit face 20. The blades extend generally radially along bit face 20 and then axially along a portion of the periphery of bit 10. Blades 31-36 are separated by drilling fluid flow courses 19.
Referring still to FIGS. 1(A) and 2, each blade, 31, 32, 33 includes a cutter-supporting surface 42 for mounting a plurality of cutter elements, and blade 34, 35, and 36 includes a cutter-supporting surface 52 for mounting a plurality of cutter elements. A plurality of forward-facing cutter elements 40, each having a primary cutting face 44, are mounted to cutter-supporting surfaces 42, 52 of blades 31, 32, 33 and blades 34, 35, 36, respectively. In particular, cutter elements 40 are arranged adjacent to one another in a radially extending row proximal the leading edge of blade 31, 32, 33 34, 35, and 36. Also mounted to cutter-supporting surfaces 42, 52 are protrusions 55 that trail behind certain cutter elements 40.
Referring still to FIGS. 1(A) and 2, bit 10 further includes gage pads 50 of substantially equal axial length measured generally parallel to bit axis 11. Gage pads 50 are disposed about the circumference of bit 10 at angularly spaced locations. Specifically, gage pads 50 intersect and extend from each blade 31-36. In this embodiment, gage pads 50 are integrally formed as part of the bit body 12.
Gage-facing surface 51 of gage pads 50 abut the sidewall of the borehole during drilling. The pads can help maintain the size of the borehole by a rubbing action when cutter elements 40 wear slightly under gage. Gage pads 50 also help stabilize bit 10 against vibration. In certain embodiments, gage pads 50 include flush-mounted or protruding cutter elements 51 a embedded in gage pads to resist pad wear and assist in reaming the side wall. Therefore, as used herein, the term “cutter element” is used to include at least the above-described forward-facing cutter elements 40, blade protrusions 55, and flush or protruding elements 51 a embedded in the gage pads, all of which may be made in accordance with the principles described herein.
Referring now to FIGS. 1A, 2, 4A, and 4B, each cutter element 40 comprises an elongated and generally cylindrical support member or substrate which is received and secured in a pocket formed in the surface of the blade or gage pad to which it is fixed. In general, each cutter element may have any suitable size and geometry. In a similar fashion FIG. 1(B) is representative of a roller cone bit made in accordance with the present disclosure wherein PDC cutters (such as those exemplified as 14-16) are positioned on cones 11, 12 and 13. FIG. 4C is an exemplary side view of a PDC cutter element used in accordance with a roller cone bit, and further FIG. 4D is representative of such a PDC cutter that is comprised of a number of different layers (41-44) which are discrete and in some embodiments are comprised of diamond powders that impart varying mechanical and thermal properties to different areas of the PDC cutter, as exemplified herein and throughout this disclosure.
Referring now to FIGS. 4A and 4B, a cutter element 40 having a cutting face 94 is shown. In general, cutter element 40 (as described in FIGS. 1A and 2) includes a polycrystalline diamond table 90 a, forming cutting face 94 and supported by a carbide substrate 90 b. The interface 90 c between PDC table 90 a and substrate 90 b is planar in this example but may likewise be non-planar. The central region 95 of cutting face 94 is planar in this embodiment, although concave, convex, or ridged surfaces may be employed. The cutting edge 90 d extends about the entire periphery of table 90 a in this example, but may extend along only a circumferential portion that is to be located adjacent the formation to be cut.
In some embodiments, the cemented carbide is a metal matrix composite where tungsten carbide particles are the aggregate and a metal binder material comprising Co, Ni, Fe, Cr, B and alloys thereof, serve as the matrix. During sintering, the binder material, such as cobalt, becomes the liquid phase and WC grains (with a higher melting point) remain in the solid phase. As a result of this process, cobalt embeds or cements the WC grains and thereby creates the metal matrix composite with its distinct material properties. The naturally ductile cobalt metal serves to offset the characteristic brittle behavior of the tungsten carbide ceramic, thus raising its toughness and durability. Properties of the substrate can be changed significantly by modifying the tungsten carbide grain size, cobalt content (e.g. alloy carbides) and carbon content.
In some embodiments, the diamond powder(s) used in the formation of the PDC cutters are chosen to impart desirable properties to the PDC cutter element by choosing the appropriate diamond for each layer. In some embodiments, the diamond powder may be comprised of particles that are sub-micron in size, in some other embodiments the diamond powder is comprised of particles that are nanometer in size, in some further embodiments the diamond powder may be comprised of a range of particle sizes. The selection of a diamond powder is however not solely dependent on the size of the diamond grain, but also the chemical diversity of the diamond or combinations thereof. Properties that can be controlled by modifying the chemical content of the diamond include, but are not limited to: electrical conductivity, strength, optical properties and thermal stability. For example a cutter element may be composed of a diamond powder comprising a dopant such as: Al, B, N, Li, K, Ti, P, and Zr, or combinations thereof.
Precise three dimensional positioning of small quantities of diamond powder(s) for PDC manufacture is difficult to achieve manually, whereby typically about 0.5 g is the minimum amount of powder that can be accurately placed by hand. Consequently, conventional PDC cutter elements employ powder deposition in simple shapes and layers, and are typically axi symmetrical, and are most often formed by the use of simple rotatable dibbers. Layers are also conventionally formed from discs cut from sheets, in a so called taped system.
Referring to FIG. 5A, a method of making a cutter element for a cutting tool such as a drill bit (as depicted in FIGS. 1-3) is shown and comprises positioning a first material layer in Step 501, which may optionally comprise a non-planer interface. In Step 502, an optional second material layer is deposited upon the first material layer. Each material layer may be formed by positioning a material with a highly accurate powder placement method. An amount of each material may be about 1 mg to about 2000 mg, wherein the material may be placed at a rate of about 1 mg per second to about 300 mg per second, and is accurately placed during assembly of the material components of the cutter element. The materials of first and second layers may be diamond powder, metal carbide powder, or other such materials. In Step 503, a substrate is positioned upon the second material layer where the substrate may be a powder or a preformed blank. High temperatures and high pressure are applied in Step 504 to accomplish the sintering of the materials, and the sintered mass is allowed to cool. Optionally, in Step 505, the sintered material, or parts thereof, undergo a leaching process.
In another embodiment a method of making a cutter element for a cutting tool such as a drill bit is presented, comprising: positioning a least a first material layer by a fill to weight system, with a less than 10% relative standard deviation; loading a substrate and sintering to form a cutter element.
In some embodiments, the method of powder placement presented herein is a fill to weight system. Whereby a fill to weight system provides a method of recording weights using a direct weighing method. The fill to weight system uses a closed loop control and a high speed loading cell which reduces variability and results in a low relative standard deviation in the weights of powders delivered. In further embodiments, positioning of the material has a relative standard deviation of less than 10%, and in other embodiments said positioning of said material has a relative standard deviation of less than about 3%.
In some embodiments, a fill to weight system includes a powder dispensing and sensing apparatus which comprises a structure to receive and hold a container; a powder dispenser assembly including powder dispenser modules to dispense powder into respective containers or regions of a container; a powder transport system to deliver powder to the powder dispenser modules from a powder supply, a sensor module including sensor cells to sense respective fill states of each of the containers; and a control system to control the powder dispenser modules in response to the respective sensed fill states of each container(s), or regions of a container(s).
In some embodiments of the method herein described, positioning of said material comprises using a first delivery head (or filling head) and a first positioning device. In other embodiments, positioning of said material comprises using at least a second delivery head and at least a second positioning device. As described in more detail below and illustrated in FIG. 5B, in some embodiments, the system is equipped with multiple filling heads and precise positioning devices which allow highly accurate three dimensional positioning of a number of different powders. Such positioning is either step wise; producing distinct boundaries between powders in different regions or zones, i.e. a “step” gradient; or by creating true or continuous gradients by varying material composition at the same time as varying position, by using multiple feeders, (see for example the plot of FIG. 5C). Therefore, in some embodiments of the method of making a cutter element described herein, positioning of said material(s) is by a step gradient, and in some embodiments the first region of material positioned may be distinct from a second region of material positioned. In other further embodiments, positioning of said material(s) is by a continuous gradient, wherein said first region is non-distinct from said second region.
Further, the sizes of nozzles used in the deliver heads can be optimized, whereby larger diameter nozzles may be used for delivery of bigger volumes of powder.
Using the methods described herein, powders can be routinely placed that weigh in the order of about 1 mg to 10000 mg, and in some embodiments smaller units of material, in the order of about 1 mg to about 2000 mg can be positioned. In some embodiments, positioning comprises positioning about 1 mg to about 100 mg of a material, in other embodiments positioning comprises positioning about 1 mg to about 50 mg of a material. In some embodiments, the first region comprises about 1 mg to about 1700 mg of a material; in other embodiments, first region comprises about 1 mg to about 400 mg of a material. Similarly, in further embodiments of the method of making a cutter element, the second region comprises about 1 mg to about 1700 mg of a material, in other embodiments, second region comprises about 1 mg to about 400 mg of a material and in other embodiments, the second region comprises about 1 mg to about 50 mg of a material. In some further embodiments, other materials may also be positioned as to impart further regions of varying materials in specific designs so as to impart desired properties to the PDC cutter elements herein described.
To deposit such small quantities of powder, the wall friction angle parameter used to quantify the level of friction between the device material and the powders being deposited is taken into consideration, and hence used in optimizing the uniformity of fill weight. Accurate, reproducible and fast deposition of small quantities of PDC materials can therefore be automated, for example, when bulk granular materials are poured onto a horizontal surface, a conical pile forms. The internal angle between the surface of the pile and the horizontal surface is known as the angle of repose and is related to the density, surface area and shapes of the particles, and the coefficient of friction of the material. Hence, in one embodiment, the powder delivery system herein described delivers 1 mg of diamond powder(s) to form a cone, wherein said cone may have a minimum height of about 0.6 mm, a minimum diameter of about 1.4 mm and an angle of repose of about 35° to about 55°.
In some embodiments, as the powder of a first layer is placed it is done so as multiple adjacent cones, thereby forming a vertical boundary between one powder layer and the next that is composed of multiple cones, the surface is in fact not flat but thus irregular, as will be the surface of the powder placed upon it placed by the same method. The interaction of such non-liner boundaries thus increases the strength of the boundary upon sintering, and reduces mechanical failures between the different diamond powder layers, thus imparting a greater overall strength to the PDC element.
In some further embodiments, the powder delivery system described herein can deliver 1 mg of powder every 0.2 seconds, thereby depositing 1 mg of powder 5 times in one second, and whereby the powder is delivered to a discrete position (A). In some embodiments the powder delivery head may be repositioned between deposits, thereby depositing 1 mg of powder 2-3 times per second in discrete positions, for example a depositing 1 mg of powder at a first position (A), a discrete deposition of 1 mg of powder at a second position (B) and a discrete deposition of 1 mg of powder at a third position (C). In a further embodiment the delivery head may deliver powder continuously as it moves for example from a first position (A) to at least a second position (B).
In another embodiment an 8 mm diameter cutter may be produced by filing an 8 mm canister with 400 mg of powder, whereby the filling may be executed by depositing the power (at a discrete position A) in 1 mg increments for a total of 80 seconds.
In a further embodiment an 8 mm diameter cutter may be produced by filling an 8 mm diameter canister with 400 mg of powder, whereby the filling may be executed by depositing the power at a first position (A), and at a second position (B) and optionally a third position (C), in 1 mg discrete deposits for a total of about 135 seconds to about 200 seconds.
In a further embodiment the delivery head may deliver 400 mg of powder continuously as it moves for example from a first position (A) to at least a second position (B).
In another embodiment, a 19 mm diameter cutter may be produced by filing a 19 mm diameter canister with about 1700 mg of diamond powder, whereby the filling may be executed by depositing the power (at a discrete position A) in 1 mg increments for a total of about 340 seconds.
In a further embodiment, a 19 mm diameter cutter may be produced by filling an 19 mm diameter canister with 1700 mg of powder, whereby the filling may be executed by depositing the power at a first position (A), and at a second position (B) and optionally a third position (C) wherein the filling is by 1 mg discrete deposits for a total of about 575 seconds to about 850 seconds.
In a further embodiment the delivery head may deliver 1700 mg of powder continuously as it moves for example, from a first position (A) to at least a second position (B).
In some other embodiments, the fill to weight delivery system herein described may produce filled canisters at a rate of about 5 canisters to about 10 canisters per minute, for example five to ten 1700 mg canisters may be filed at a rate of about 140 mg/second to about 280 mg/second with one size of diamond powder, wherein the powder is delivered continuously; in another embodiment different sizes of diamond powder or different types of diamond powders may be used.
The above methodology may be used to fill canisters of varying size, utilizing the fill techniques described herein to position powder(s) in a discrete or a continuous manner with such described accuracy and speed to create powder placement patterns exemplified but not limited to the patterns described herein. The cutters described above are then formed by treating the loaded canisters as described herein and throughout the current application.
In some embodiments, powders deposited by this method may be diamond powder; metal powder; or any other desired powdered material; or combinations thereof.
Powders, therefore may be mono or multi modal, being mixes of materials and/or particle size. Therefore in some embodiments of the methods of making cutter elements described herein, the material(s) comprises mono-modal properties, multi-modal properties or combinations thereof, and in some embodiments said properties may comprise physical composition, chemical composition or combinations thereof. As previously described, in some embodiments, said physical composition comprises, particle size, shape, density, thermal conductivity, porosity or combinations thereof, and in other embodiments, the chemical composition comprises doped diamond or un-doped diamond.
In some embodiments, materials used in different regions include mono modal properties or multi modal properties, of combinations thereof.
In other embodiments, powders may be placed to create characteristics in the finished PDC, such as to impart specific wear shapes; different leaching characteristics or rates of leaching; provide leachable and non-leachable regions; and produce PDC elements with a variation in thermal conductivities. Further, powders may be placed to optimize residual stresses, such as to reduce interfacial failure between different powders (such as diamond and substrate) by generating non planer interfaces (NPI's) or textured interfaces; or reduce interfacial failure between leached and unleached regions of the cutter, again by generating (NPI's) or textured interfaces; to position powders in relation to substrate geometry for optimal packing density and for identification, such as to generate identification/part numbers or company logo's.
Therefore in some embodiments, a cutter element is herein described that comprises a substrate; and a polycrystalline diamond table coupled to the substrate, wherein the table comprises at least 1 mg of a first material, wherein the first material is at least 0.6 mm in height and at least 1.4 mm in width and comprises at least a first region of the table; and at least 1 mg of a second material, wherein the second material is at least 0.6 mm in height and at least 1.4 mm in width and comprises at least a second region of the table, and wherein at least one region comprises a material that is positioned by a fill to weight system, and is positioned at a rate of about 1 mg per second to about 280 mg per second.
Such cutter elements are ultimately employed on cutting tools, such as the drill bit illustrated in FIGS. 1-3. In some embodiments, a drill bit for drilling a borehole in earthen formations, comprises a plurality of cutter elements mounted on the bit, wherein the cutter elements comprise a substrate; and a polycrystalline diamond table coupled to the substrate, wherein the table comprises at least 1 mg of a first material, wherein the first material is at least 0.6 mm in height and at least 1.4 mm in width and comprises a first region of the polycrystalline diamond table; and at least 1 mg of a second material, wherein the second material is at least 0.6 mm in height and at least 1.4 mm in width and comprises at least a second region of the polycrystalline diamond table; wherein at least one region comprises a material that is positioned by a fill to weight system, and is positioned at a rate of about 1 mg per second to about 280 mg per second.
As such, some non-limiting examples of processing conditions and parameters are now described for the purpose of illustrating certain exemplary embodiments of the present invention.

EXAMPLES

Example 1A

Three Dimensional Positioning of Powders to Form a Non Planer Interface

FIG. 6A depicts an exemplary embodiment of a method of producing a PDC cutter element herein described. A pre-formed substrate 60 is loaded into a canister containing pre-positioned powders. In more detail, a diamond powder 61 is first positioned in the base of the canister to form a non-planer surface 62. A carbide powder 63 is then positioned onto the diamond powder 61, thereby forming a non-planer interface 62 between the two powders. The pre-formed substrate blank 60 is then loaded onto the carbide layer 63. The assembled canister then undergoes sintering to form a PDC cutter element. In other embodiments the preformed substrate 60 may be loaded into the can first and powders assembled above the substrate. In other embodiments the substrate may be added to the canister as a powder, rather than as a preformed blank.
The non planer interface 62 is formed by positioning a diamond powder layer or another super abrasive material in the base of the canister as depicted in the flow chart of FIG. 5A. For example, a diamond layer may be positioned into the base of the canister (or in other embodiments, onto a pre positioned powder), whereby the positioning heads and delivery device are set to place a varying depth of powder ranging from about 0.1 mm to about 5 mm across the entire base The depth profile (D) (as indicated in FIG. 6A) of deposited powder 61 may be sequentially repeated to form a repeating pattern, thereby creating a reproducible, uniform non-planer interface (NPI) 62 across the entire PDC element
A second powder 63 comprising a metal carbide, such as tungsten carbide is then accurately placed upon the NPI 62 in a similar fashion. The precise positioning of powders creates an interlocking pattern with the previously deposited diamond powder 61. A flat uniform surface 64 is formed onto which the substrate blank 60 is placed. The assembled can is sintered and cooled. The resultant cutter is formed with a non-planer interface between the hard diamond table 61 and the tungsten carbide 63 that, in conjunction with substrate blank 60, forms the substrate for the sintered diamond powder 61. As described above, the formation of a NPI 62 decreases the residual stresses between the diamond table and the substrate on cooling of the cutter, thereby creating a cutter that is less prone to a catastrophic delamination event in-service. In further embodiments, each distinct layer 61, 63 may comprise materials that are selected to impart varying degrees of thermal stability, abrasion resistance, and toughness.

Example 1B

Three Dimensional Positioning of Powders to Form a Non Planer Cutting Surface

In a further embodiment of the method described herein, powders are placed in a similar fashion to example 1A. However, FIG. 6B depicts the placement of an erodible powder 65 (such as metal carbide) in the base of the canister, whereby the positioning heads and delivery device are set to place a varying depth of erodible powder ranging from about 0.1 mm to about 2 mmmm in depth into the base of the canister. The depth profile (D) of powder deposited may be sequentially and uniformly repeated (forming a repeat unit/pattern) to produce a non-planer interface 66 having a defined pattern that repeats across the entire PDC element. A second powder 61 comprising diamond is then accurately placed upon the NPI 66 in a similar fashion as described above. The precise positioning of powders creates an interlocking pattern with the previously deposited erodible powder 65, and a flat uniform surface 67 onto which the substrate blank 60 is placed. The assembled can is sintered and cooled. After sintering, the erodible material 65 can easily be removed, for example by grit blasting, to produce a PDC cutting element with a diamond table comprising a non-planer cutting surface 68.
Such a method of producing a non-planar cutting surface is inexpensive and is a simplified manufacturing process as compared to some conventional methods. In addition, the precise fill to weight method allows for the highly accurate and reproducible placement of powders allowing intricate surface designs to impart properties such as thermal stability, abrasion resistance and impact resistance to the entire PDC cutting element or selected regions thereof. The reproducibility of the design of such a PDC cutter also allows for analysis of forces experienced within the cutter, and accurate prediction of in-service behavior.
FIGS. 7A and 7B are further exemplary embodiments of PDC cutters formed by the method depicted in the flow chart of FIG. 5A. Powders are precisely placed using the fill to weight system described above, whereby selected areas comprised of differentially erodible powders 65 are positioned to create regions on the cutting edge of the PDC cutter elements that will wear at different rates. In addition, in some embodiments, the erodible powder 65 are removed prior to the PDC cutter being placed in service by a blasting step after sintering, to create the specific desired geometry imparted by the specific placement of the powders 65, 61. For example, FIG. 7A depicts a PDC cutter that will experience more erosion at the edges of the PDC cutting face by virtue of the positioning of the erodible powder 65, and therefore will produce a rather frustoconical cutting surface 69, after undergoing blasting or after wear when placed in service.
FIG. 7B depicts a PDC cutter that will experience more erosion in the center of the PDC cutting face by virtue of the central positioning of the erodible powder 65, and therefore will produce a concaved wear surface once blasted or placed in service.

Example 2A

Optimization of Powder Packing Density

FIGS. 8A and 8B show examples of conventional powder placement during canister assembly for PDC cutter manufacture. It can be seen from each of these figures that there are inherent practical difficulties in loading powders into canisters manually. For example it can been seen in FIG. 8A, that in some cases, manual placement of diamond powder results in a poor fit between the shape of the pre-placed powders 71 and the geometry of the substrate blank 72 in the region 77, resulting in the sides 75 of the canister being slightly under-packed and the base 76 of the canister being over-packed.
Such inaccuracies occur typically due to the difficulties of manual placement. The placement of about 0.5 g is typically the most accurate amount that is positionable manually. Also, it is extremely difficult to create a three dimensionally accurate receiving pattern by a manual process. Hence, the imperfection of the fit between the powders 71 that are pre-positioned in the canister and the blank 72 results in: irregularities in the sintering process; unpredictable leaching results due to varied leaching rates; higher levels of residual stresses between the diamond table and the substrate; all of which result in unpredictable PDC cutter quality and performance. As such, conventional cutters often display decreased abrasion resistance and toughness.
FIG. 8C is an exemplary embodiment of a method of making a PDC cutter herein described. Using the method detailed in the flow chart of FIG. 5A, the highly accurate fill to weight system may be used to deposit (position) a diamond powder 61 in a distinct three dimensional, non-planar configuration 80, formed to accurately receive the shape of the substrate blank 82, thereby allowing for uniform packing and optimizing the packing density of the assembled canister. The canister subsequently is sintered and optionally leached. The optimization of powder placement results in a PDC cutter with known and reproducible properties. Hence the optimization of powder placement leads to the production of PDC cutters with increased reliability in-service.
The herein described method of powder placement may also be used to manufacture cutter elements such as those illustrated in FIGS. 9 a and 9 b which represent cutter elements which is some embodiments are comprised of discrete layers of diamond (61-64). The diamond layers may be comprised of different diamond/carbide powder mixes, or mixes of different types of diamonds which have varying properties. In some embodiments the outer-layers will be comprised increasingly of diamond, and the carbide content will decrease accordingly.
Further, such three dimensional geometric placement of powders may be coupled with additional cutter designs, whereby each distinct powder layer may be composed of materials that are selected to impart varying degrees of thermal stability, abrasion resistance, and toughness. For example, as a drill bit forms a borehole, the bit will encounter and be required to drill through layers of formation material having varying characteristics (e.g., hardness, abrasiveness, other). As such, the cutting surface of the cutter elements may be designed so as to erode at a rate that corresponds to the change in type of rock formation that the cutters contact in service. Therefore, as the cutter wears, it exposes a different layer or portion of material that is optimized for maximum efficiency in each geological formation encountered. Cutters can therefore be optimized by layer or portion for a known geological formation. Further, during drilling of a well there is often need to machine out metal components in the well bore, for example steel lining casing may be run in the well and cemented in place and it may be necessary to mill a hole in the casing for a side track or lateral well as disclosed in U.S. Pat. No. 6,612,383 and U.S. Pat. No. 8,191,654 and incorporated herein in their entirety. It is therefore desirable to have bits designs and cutters than can both machine the metal parts of the casing and also a length of the rock formation, and in some embodiments be capable of drilling through a casing bit disposed at an end of a casing or liner string and cementing equipment or other components such as float equipment. The methods described herein may be used to manufacture PDC cutters optimised for such purposes.
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the methods and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.

Claims

1. A method of making a cutter element for a cutting tool comprising:

positioning at least a first material layer of powder in a container;

positioning a second material layer adjacent to said at least a first material layer, to form a non-planer interface between said first and second material layer, wherein said positioning is by a fill to weight system, and said positioning comprises depositing said first material layer and said second material layer at a rate of about 1 mg per second to about 300 mg per second;

loading a substrate in the container; and

sintering to form a cutter element.

2. The method of making a cutter element of claim 1, wherein said first material layer comprises: diamond powder; and said second material layer comprises metal carbide.

3. The method of making a cutter element of claim 2, wherein said first material layer comprises metal carbide.

4. The method of making a cutter element of claim 3, further comprising:

removing the metal carbide to form a non-planer cutter surface.

5. The method of making a cutter element of claim 1, wherein said positioning optimizes packing density between said material and said substrate, forming a uniform interface between said material and said substrate.

6. The method of claim 1, further comprising:

positioning a second material in the container adjacent to said first material; and

after sintering, eroding one of said first and second materials.

7. The method of claim 1, wherein said positioning of said first material comprises positioning about 1 mg to about 1700 mg.

8. A cutter element comprising: a substrate; and at least a first material layer, wherein said element is made by the method of claim 1.

9. The cutter element of claim 8, wherein said first material is coupled to the substrate through a non-planer interface.

10. The cutter element of claim 8, further comprising a second material layer, wherein said second layer is coupled to the first layer through a non-planer interface.

11. The cutter element of claim 10, wherein the second material layer comprises metal carbide.

12. The cutter element of claim 8, further comprising an erodible material layer, wherein said erodible material layer is coupled to the first material layer through a non-planer interface.

13. The cutter element of claim 12, wherein said erodible material comprises the cutting face of the cutter element.

14. The cutter element of claim 12, wherein said erodible material comprises metal carbide.

15. The cutter element of claim 8, further comprising an erodible material layer forming at least a portion of the cutting face of the cutter element.

16. The cutter element of claim 8, wherein said first material possesses mono-modal properties, multi-modal properties or combinations thereof, wherein said properties comprise physical composition, chemical composition or combinations thereof.

17. The cutter element of claim 16, wherein said physical composition comprises, particle size, particle shape, density, thermal conductivity, porosity or combinations thereof.

18. The cutter element of claim 8, further comprising a second material, wherein said second material layer comprises polycrystalline diamond and said first layer is an erodible material, wherein said erodible material comprises a region of the cutting face of said element.

19. The cutter element of claim 13, wherein said region is concaved.

20. The cutter element of claim 13, wherein said region comprises perimeter of the cutting face.