EP2049769A2

EP2049769A2 - Thick pointed superhard material

Info

Publication number: EP2049769A2
Application number: EP07873780A
Authority: EP
Inventors: Ronald B. Crockett
Original assignee: Hall, David R.
Current assignee: Services Petroliers Schlumberger SA; Schlumberger Holdings Ltd; Prad Research and Development Ltd; Schlumberger Technology BV
Priority date: 2006-08-11
Filing date: 2007-08-16
Publication date: 2009-04-22
Anticipated expiration: 2027-08-16
Also published as: WO2008105915A2; WO2008105915A3; EP2049769B1; EP2049769A4

Abstract

In one aspect of the invention, a high impact resistant tool having a superhard bonded to a cemented metal carbide substrate at a non-planar interface. The superhard material has a substantially pointed geometry with a sharp apex having.050 to.125 inch radius. The superhard material also has a.100 to.500 inch thickness from the apex to the non-planar interface.

Description

Thick Pointed Superhard Material

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Patent Application 11/463,953 to Hall filed on August 11, 2006; U.S. Patent Application 11/463,990 to Hall filed on August 11, 2006; U.S. Patent Application 11/553,338 to Hall filed on October 26, 2006; U.S. Patent Application 11/558,835 to Hall filed on November 10, 2006; U.S. Patent Application 11/668,254 to Hall filed on January 29, 200; and U.S. Patent Application 11/673,634 to Hall filed on February 12, 2007. All of these applications have a common inventor and are commonly owned by David R. Hall. All of the abovementioned applications are herein incorporated by reference for all that they contain.

BACKGROUND OF THE INVENTION The invention relates to a high impact resistant tool that may be used in machinery such as crushers, picks, grinding mills, roller cone bits, rotary fixed cutter bits, earth boring bits, percussion bits or impact bits, and drag bits. More particularly, the invention relates to inserts comprised of a carbide substrate with a non-planar interface and an abrasion resistant layer of super hard material affixed thereto using a high pressure high temperature press apparatus. Such inserts typically comprise a super hard material layer or layers formed under high temperature and pressure conditions, usually in a press apparatus designed to create such conditions, cemented to a carbide substrate containing a metal binder or catalyst such as cobalt. The substrate is often softer than the super hard material to which it is bound. Some examples of super hard materials that high pressure high temperature (HPHT) presses may produce and sinter include cemented ceramics, diamond, polycrystalline diamond, and cubic boron nitride. A cutting element or insert is normally fabricated by placing a cemented carbide substrate into a container or cartridge with a layer of diamond crystals or grains loaded into the cartridge adjacent one face of the substrate. A number of such cartridges are typically loaded into a reaction cell and placed in the high pressure high temperature press apparatus. The substrates and adjacent diamond crystal kyers are then compressed under HPHT conditions which promotes a sintering of the diamond grains to form the polycrystalline diamond structure. As a result, the diamond grains become mutually bonded to form a diamond layer over the substrate interface. The diamond layer is also bonded to the substrate interface.

Such inserts are often subjected to intense forces, torques, vibration, high temperatures and temperature differentials during operation. As a result, stresses within the structure may begin to form. Drill bits for example may exhibit stresses aggravated by drilling anomalies during well boring operations such as bit whirl or bounce often resulting in spalling, delamination or fracture of the super hard abrasive layer or the substrate thereby reducing or eliminating the cutting elements efficacy and decreasing overall drill bit wear life. The superhard material layer of an insert sometimes delaminates from the carbide substrate after the sintering process as well as during percussive and abrasive use. Damage typically found in percussive and drag bits may be a result of shear failures, although non- shear modes of failure are not uncommon The interface between the superhard material layer and substrate is particularly susceptible to non- shear failure modes due to inherent residual stresses.

US Patent No. 5,544,713 by Dennis, which is herein incorporated by reference for all that it contains, discloses a cutting element which has a metal carbide stud having a conic tip formed with a reduced diameter hemispherical outer tip end portion of said metal carbide stud. The tip is shaped as a cone and is rounded at the tip portion. This rounded portion has a diameter which is 35-60% of the diameter of the insert.

US Patent No. 5,848,657 by Flood et al, which is herein incorporated by reference for all that it contains, discloses domed polycrystalline diamond cutting element wherein a hemispherical diamond layer is bonded to a tungsten carbide substrate, commonly referred to as a tungsten carbide stud. Broadly, the inventive cutting element includes a metal carbide stud having a proximal end adapted to be placed into a drill bit and a distal end portion. A layer of cutting polycrystalline abrasive material disposed over said distal end portion such that an annulus of metal carbide adjacent and above said drill bit is not covered by said abrasive material layer.

US Patent No. 4,109,737 by Bovenkerk which is herein incorporated by reference for all that it contains, discloses a rotary bit for rock drilling comprising a plurality of cutting elements mounted by interence- fit in recesses in the crown of the drill bit. Each cutting element comprises an elongated pin with a thin layer of polycrystalline diamond bonded to the free end of the pin.

US Patent Application Serial No. 2001/0004946 by Jensen, although now abandoned, is herein incorporated by reference for all that it discloses. Jensen teaches that a cutting element or insert with improved wear characteristics while maximizing the manufacturability and cost effectiveness of the insert. This insert employs a superabrasive diamond layer of increased depth and by making use of a diamond layer surface that is generally convex.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, a high impact resistant tool has a superhard material bonded to a cemented metal carbide substrate at a non-planar interface. At the interface, the substrate has a tapered surface starting from a cylindrical rim of the substrate and ending at an elevated flatted central region formed in the substrate. The superhard material has a pointed geometry with a sharp apex having .050 to .125 inch radius. The superhard material also has a .100 to .500 inch thickness from the apex to the flatted central region of the substrate. In other embodiments, the substrate may have a non-planar interface. The interface may comprise a slight convex geometry or a portion of the substrate may be slightly concave at the interface. The substantially pointed geometry may comprise a side which forms a 35 to 55 degree angle with a central axis of the tool. The angle may be substantially 45 degrees. The substantially pointed geometry may comprise a convex and/or a concave side. In some embodiments, the radius may be .090 to .110 inches. Also in some embodiments, the thickness from the apex to the non-planar interface may be .125 to .275 inches.

The substrate may be bonded to an end of a carbide segment. The carbide segment may be brazed or press fit to a steel body. The substrate may comprise a 1 to 40 percent concentration of cobalt by weight. A tapered surface of the substrate may be concave and/or convex. The taper may incorporate nodules, grooves, dimples, protrusions, reverse dimples, or combinations thereof. In some embodiments, the substrate has a central flatted region with a diameter of .125 to .250 inches.

The superhard material and the substrate may comprise a total thickness of .200 to .700 inches from the apex to a base of the substrate. In some embodiments, the total thickness may be up to 2 inches. The superhard material may comprise diamond, polycrystalline diamond, natural diamond, synthetic diamond, vapor deposited diamond, silicon bonded diamond, cobalt bonded diamond, thermally stable diamond, polycrystalline diamond with a binder concentration of 1 to 40 weight percent, infiltrated diamond, layered diamond, monolithic diamond, polished diamond, course diamond, fine diamond, cubic boron nitride, diamond impregnated matrix, diamond impregnated carbide, metal catalyzed diamond, or combinations thereof A volume of the superhard material may be 75 to 150 percent of a volume of the carbide substrate. In some embodiments, the volume of diamond may be up to twice as much as the volume of the carbide substrate. The superhard material may be polished. The superhard material may be a polycrystalline superhard material with an average grain size of 1 to 100 microns. The superhard material may comprise a 1 to 40 percent concentration of binding agents by weight. The tool of the present invention comprises the characteristic of withstanding impacts greater than 80 joules. The high impact tool may be incorporated in drill bits, percussion drill bits, roller cone bits, shear bits, milling machines, indenters, mining picks, asphalt picks, cone crushers, vertical impact mills, hammer mills, jaw crushers, asphalt bits, chisels, trenching machines, or combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective diagram of an embodiment of a high impact resistant tool.

Fig. 2 is a cross- sectional diagram of an embodiment of a pointed geometry. Fig. 2a is a cross- sectional diagram of another embodiment of a superhard geometry.

Fig. 3 is a cross- sectional diagram of an embodiment of a superhard geometry.

Fig. 3a is a diagram of an embodiment of test results.

Fig. 3b is diagram of an embodiment of FEA of a superhard geometry.

Fig. 3c is diagram of an embodiment of Finite Element Analysis of a pointed geometry. Fig. 4 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 5 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 6 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 7 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 8 is a cross- sectional diagram of another embodiment of a pointed geometry. Fig. 9 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 10 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 11 is a cross- sectional diagram of another embodiment of a pointed geometry.

Fig. 12 is a cross- sectional diagram of another embodiment of a tool.

Fig. 13 is a cross- sectional diagram of another embodiment of a tooL Fig. 14 is a cross- sectional diagram of another embodiment of a tooL

Fig. 14a is a perspective diagram of an embodiment of high impact resistant tools.

Fig. 15 is a cross- sectional diagram of an embodiment of an asphalt milling machine.

Fig. 16 is an orthogonal diagram of an embodiment of a percussion bit.

Fig. 17 is a cross- sectional diagram of an embodiment of a roller cone bit. Fig. 18 is a perspective diagram of an embodiment of a drill bit.

Fig. 19 is an orthogonal diagram of an embodiment of a drill bit.

Fig. 20 is a perspective diagram of another embodiment of a trenching machine.

Fig. 21 is a cross- sectional diagram of an embodiment of a jaw crusher. Fig. 22 is a cross- sectional diagram of an embodiment of a hammer mill.

Fig. 23 is a cross- sectional diagram of an embodiment of a vertical shaft impactor.

Fig. 24 is a cross- sectional diagram of an embodiment of a cone crusher.

Fig. 25 is an orthogonal diagram of another embodiment of a tool. Fig. 26 is an orthogonal diagram of another embodiment of a tool.

Fig. 27 is a perspective diagram of an embodiment of a second segment.

Fig. 28 is an exploded view of an embodiment of a tool.

Fig. 29 is an orthogonal diagram of another embodiment of a tool.

Fig. 30 is an orthogonal diagram of another embodiment of a tool. Fig. 31 is an orthogonal diagram of another embodiment of a tool.

Fig. 32 is an orthogonal diagram of another embodiment of a tool.

Fig. 33 is an orthogonal diagram of another embodiment of a tool.

Fig. 34 is an orthogonal diagram of another embodiment of a tool.

Fig. 35 is a cross- sectional diagram of an embodiment of a shank. Fig. 36 is a cross- sectional diagram of another embodiment of a shank.

Fig. 37 is a cross- sectional diagram of an embodiment of a shank and first segment.

Fig. 38 is a cross- sectional diagram of an embodiment of a shank and first segment.

Fig. 39 is an orthogonal diagram of another embodiment of a tool.

Fig. 40 is a cross- sectional diagram of an embodiment of a shank and first segment. Fig. 41 is a perspective cross- sectional diagram of a holder.

Fig. 42 is a cross- sectional diagram of another embodiment of a tool.

Fig. 43 is a cross- sectional diagram of an embodiment of a tip.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

Fig. 1 discloses an embodiment of a high impact resistant tool 100 which may be used in machines in mining, asphalt milling, or trenching industries. The tool 100 may comprise a shank 101 and a body 102, the body 102 being divided into first and second segments 103, 104. The first segment 103 may generally be made of steel, while the second segment 104 may be made of a harder material such as a cemented metal carbide. The second segment 104 may be bonded to the first segment 103 by brazing to prevent the second segment 104 from detaching from the first segment 103. The shank 101 may be adapted to be attached to a driving mechanism, such as an asphalt milling or mining drum. A protective spring sleeve 105 may be disposed around the shank 101 both for protection and to allow the high impact resistant tool to be press fit into a holder while still being able to rotate. A washer 106 may also be disposed around the shank 101 such that when the high impact resistant tool 100 is inserted into a holder, the washer 106 protects an upper surface of the holder and also facilitates rotation of the tooL The washer 106 and sleeve 105 may be advantageous since they may protect the holder which may be costly to replace.

The high impact resistant tool 100 also comprises a tip 107 bonded to a frustoconical end 108 of the second segment 104 of the body 102 at a planar interface 150. The tip 107 comprises a superhard material 109 bonded to a cemented metal carbide substrate 110 at a non-planar interface. The tip may be bonded to the substrate through a high temperature high pressure process. The superhard material 109 may comprise diamond, polycrystalline diamond, natural diamond, synthetic diamond, vapor deposited diamond, silicon bonded diamond, cobalt bonded diamond, thermally stable diamond, polycrystalline diamond with a binder concentration of 1 to 40 weight percent, infiltrated diamond, layered diamond, monolithic diamond, polished diamond, course diamond, fine diamond, cubic boron nitride, diamond impregnated matrix, diamond impregnated carbide, non-metal catalyzed diamond, or combinations thereof.

The superhard material 109 may be a polycrystalline structure with an average grain size of 10 to 100 microns. The cemented metal carbide substrate 110 may comprise a 1 to 40 percent concentration of cobalt by weight, preferably 5 to 10 percent. During high temperature high pressure (HTHP) processing, some of the cobalt may infiltrate into the superhard material such that the substrate comprises a slightly lower cobalt concentration than before the HTHP process. The superhard material may preferably comprise a 1 to 5 percent cobalt concentration by weight after the cobalt or other binder infiltrates the superhard material. The superhard material may also comprise a 1 to 5 percent concentration of tantalum by weight as a binding agent. Other binders that may be used which include iron, cobalt, nickel, silicon, hydroxide, hydride, hydrate, phosphorus-oxide, phosphoric acid, carbonate, lanthanide, actinide, phosphate hydrate, hydrogen phosphate, phosphorus carbonate, alkali metals, ruthenium, rhodium, niobium, palladium, chromium, molybdenum, manganese, tantalum or combinations thereof. In some embodiments, the binder is added directly to the superhard material's mixture before the HTHP processing and does not rely on the binder migrating from the substrate into the mixture during the HTHP processing.

Now referring to Fig. 2, the substrate 110 comprises a tapered surface 200 starting from a cylindrical rim 250 of the substrate and ending at an elevated, flatted, central region 201 formed in the substrate. The superhard material 109 comprises a substantially pointed geometry 210 with a sharp apex 202 comprising a radius of .050 to .125 inches. In some embodiments, the radius is .900 to .110 inches. It is believed that the apex 202 is adapted to distribute impact forces across the flatted region 201, which may help prevent the superhard material 109 from chipping or breaking. The superhard material 109 may comprise a thickness 203 of .100 to .500 inches from the apex to the flatted region or non-planar interface, preferably from .125 to .275 inches.

The superhard material 109 and the substrate 110 may comprise a total thickness 204 of .200 to .700 inches from the apex 202 to a base 205 of the substrate 110. The sharp apex 202 may allow the tool to more easily cleave asphalt, rock, or other formations.

The pointed geometry of the superhard material 109 may comprise a side which forms a 35 to 55 degree angle 150 with a central axis of the tool, though the angle 150 may preferably be substantially 45 degrees. The included angle may be a 90 degree angle, although in some embodiments, the included angle is 85 to 95 degrees. The pointed geometry may also comprise a convex side or a concave side. The tapered surface of the substrate may incorporate nodules 207 at the interface between the superhard material and the substrate, which may provide more surface area on the substrate to provide a stronger interface. The tapered surface may also incorporate grooves, dimples, protrusions, reverse dimples, or combinations thereof. The tapered surface may be convex or concave.

Comparing Figs. 2 and 3, the advantages of having a pointed apex 202 as opposed to a blunt apex 300 may be seen. Fig. 2 is a representation of a pointed geometry which was made by the inventors of the present invention, which has a .094 inch radius apex and a .150 inch thickness from the apex to the non-planar interface. Fig. 3 is a representation of another geometry also made by the same inventors comprising a .160 inch radius apex and .200 inch thickness from the apex to the non-planar geometry. The superhard geometries were compared to each other in a drop test performed at Novatek International, Inc. located in Provo, Utah. Using an Instron Dynatup 9250G drop test machine, the tools were secured to a base of the machine and weights comprising tungsten carbide targets were dropped onto the superhard geometries. The pointed apex 202 of Fig. 2 surprisingly required about 5 times more joules to break than the thicker geometry of Fig. 3.

It was shown that the sharper geometry of Fig. 2 penetrated deeper into the tungsten carbide target, thereby allowing more surface area of the superhard material to absorb the energy from the falling target by beneficially buttressing the penetrated portion of the superhard material effectively converting bending and shear loading of the diamond substrate into a more beneficial quasi- hydrostatic type compressive forces drastically increasing the load carrying capabilities of the superhard material. On the other hand since the embodiment of Fig. 3 is blunter the apex hardly penetrated into the tungsten carbide target thereby providing little buttress support to the diamond substrate and caused the superhard material to fail in shear/bending at a much lower load with larger surface area using the same grade of diamond and carbide. The average embodiment of Fig. 2 broke at about 130 joules while the average geometry of Fig. 3 broke at about 24 joules. It is believed that since the load was distributed across a greater surface area in the embodiment of Fig. 2 it was capable of withstanding a greater impact than that of the thicker embodiment of Fig. 3. Surprisingly, in the embodiment of Fig. 2, when the superhard geometry finally broke, the crack initiation point 251 was below the radius. This is believed to result from the tungsten carbide target pressurizing the flanks of the pointed geometry in the penetrated portion, which results in the greater hydrostatic stress loading in the pointed geometry. It is also believed that since the radius was still intact after the break, that the pointed geometry will still be able to withstand high amounts of impact, thereby prolonging the useful life of the pointed geometry even after chipping.

Fig. 3a illustrates the results of the tests performed by Novatek, International, Inc. As can be seen, three different types of pointed insert geometries were tested. This first type of geometry is disclosed in Fig. 2a which comprises a .035 inch superhard geometry and an apex with a .094 inch radius. This type of geometry broke in the 8 to

15 joules range. The blunt geometry with the radius of .160 inches and a thickness of .200, which the inventors believed would outperform the other geometries broke in the 20-25 joule range. The pointed geometry with the .094 thickness and the .150 inch thickness broke at about 130 joules. The impact force measured when the superhard geometry with the .160 inch radius broke was 75 kilo-Newtons. Although the Instron drop test machine was only calibrated to measure up to 88 kilo-Newtons, which the pointed geometry exceeded when it broke, the inventors were able to extrapolate that the pointed geometry probably experienced about 105 kilo-Newtons when it broke.

As can be seen, superhard material having the feature of being thicker than .100 inches or having the feature of a .075 to .125 inch radius is not enough to achieve the superhard material's optimal impact resistance, but it is synergistic to combine these two features. In the prior art, it was believed that a sharp radius of .075 to .125 inches of a superhard material such as diamond would break if the apex were too sharp, thus rounded and semispherical geometries are commercially used today.

The performance of the present invention is not presently found in commercially available products or the prior art. Inserts tested between 5 and 20 joules have been acceptable in most commercial applications, but not suitable for drilling in hard rock.

After the surprising results of the above test, Finite Element Analysis (FEA) was performed, the results of which are shown in Figs. 3b and 3c. Fig. 3b discloses the superhard geometry, with a radius of .160 inches and a thickness of .200 inches under the load in which it broke while Fig. 3c discloses the pointed geometry with the .094 radius and the .150 inch thickness under the load that it broke under. As illustrated, each embodiment comprises a superhard material 109, a substrate 110 and a tungsten carbide segment 103. Both embodiments broke at the same stress, but due to the geometries of the superhard material 109, that VonMises level was achieved under significantly different loads since the pointed apex 202 distributed the stresses more efficiently than the blunt apex 300. In Figs. 3b and 3c stress concentrations are represented by the darkness of the regions, the lighter regions represent lower the stress concentrations and the darker regions represent greater VonMises stress concentration. As can be seen the stress in the embodiment of Fig. 3b is concentrated near the apex and are both larger and higher in bending and shear, while the stress in Fig. 3c distributes the stresses lower and more efficiently due to their hydrostatic nature.

Since high and low stresses are concentrated in the superhard material transverse rupture is believed to actually occur in the superhard material, which is generally more brittle than the softer carbide substrate. The embodiment of Fig. 3c however has the majority of high stress in the superhard material while the lower stresses are actual in the carbide substrate which is more capable of handling the transverse rupture. Thus, it is believed that the geometry's thickness is critical to its ability to withstand greater impact forces; if it is too thick the transverse rupture will occur, but if it is too thin the superhard material will not be able to support itself and break at lower impact forces. Figs. 4 through 10 disclose various possible embodiments comprising different combinations of tapered surface 200 and conical surface 210 geometries. Fig. 4 illustrates the pointed geometry with a concave side 450 and a continuous convex substrate geometry 451 at the interface 200. Fig. 5 comprises an embodiment of a thicker superhard material 550 from the apex to the non-planar interface, while still maintaining this radius of .075 to .125 inches at the apex. Fig. 6 illustrates grooves 650 formed in the substrate to increase the strength of interface. Fig. 7 illustrates a slightly concave geometry at the interface with concave sides 750. Fig. 8 discloses slightly convex sides 850 of the pointed geometry while still maintaining the .075 to .125 inch radius. Fig. 9 discloses a flat sided pointed geometry 950. Fig. 10 discloses concave and convex portions 1050, 1051 of the substrate with a generally flatted central portion.

Now referring to Fig. 11, the superhard material 109 (number not shown in the fig.) may comprise a convex surface comprising different general angles at a lower portion 1100, a middle portion 1101, and an upper portion 1102 with respect to the central axis of the tool. The lower portion 1100 of the side surface may be angled at substantially 25 to 33 degrees from the central axis, the middle portion 1101, which may make up a majority of the convex surface, may be angled at substantially 33 to 40 degrees from the central axis, and the upper portion 1102 of the side surface may be angled at about 40 to 50 degrees from the central axis. Fig. 12 discloses the second segment 104 may be press fit into a bore 1200 of the first segment 103. This may be advantageous in embodiments which comprise a shank 101 coated with a hard material. A high temperature may be required to apply the hard material coating to the shank, which may affect a brazed bond between the first and second segments 103, 104 at interface 151 when the segments have been brazed together beforehand. The same may occur if the segments are brazed together after the coating is applied, wherein a high temperature braze may affect the hard material coating. A press fit may allow the second segment 104 to be attached to the first segment 103 without affecting any other coatings or brazes on the tool 100. The depth of the bore 1200 and size of the second segment 104 may be adjusted to optimize wear resistance and cost effectiveness to reduce body wash and wear to segment 103.

Fig. 13 discloses the tool 100 may comprise one or more rings 1300 of hard metal or superhard material disposed around the first segment, as in the embodiment of Fig. 13. The ring 1300 may be inserted into a groove 1301 or recess formed in the first segment. The ring 1300 may also comprise a tapered outer circumference such that the outer circumference is flush with the first segment 103. The ring 1300 may protect the first segment 103 from excessive wear that could affect the press fit of the second segment 104 in the bore 1200 of the first segment. The first segment 103 may also comprise carbide buttons or other strips adapted to protect the first segment 103 from wear due to corrosive and impact forces. Silicon carbide, diamond mixed with braze material, diamond grit, or hard facing may also be placed in groove or slots formed in the first segment of the tool to prevent the segment from wearing. In some embodiments, epoxy with silicon carbide or diamond may be used. The high impact resistant tool 100 may be rotationally fixed during an operation, as in the embodiment of Fig. 14. A portion of Ihe shank 101 may be threaded to provide axial support to the tool, and so that the tool may be inserted into a holder in a trenching machine, a milling machine, or a drilling machine. The planar surface of the second segment may be formed such that the tip 107 is presented at an angle with respect to a central axis 1400 of the tooL

Fig. 14a discloses several pointed insert of superhard material disposed along a row. The pointed inserts 210 comprise flats 1450 on their periphery to allow their apexes 202 to get closer together. This may be beneficial in applications where it is desired to minimize the amount of material that flows between the pointed inserts. The high impact resistant tool 100 may be used in many different embodiments.

The tool may be a pick in an asphalt milling machine 1500, as in the embodiment of Fig. 15. The pointed inserts as disclosed above have been tested in the US. and have lasted 10 to 15 times the life of the currently available commercial milling teeth. The tool may be an insert in a drill bit, as in the embodiments of Figs. 16 through 19. In percussion bits, such as shown in Fig. 16, the pointed geometry maybe useful in central locations 1651 on the bit face 1650 or at the gauge 1652 of the bit face. Further the pointed geometry may be useful in roller cone bits 1800, such as shown in Fig. 17, where the inserts typically fail the formation through compression. The pointed geometries may be angled to enlarge the gauge well bore. Fig. 18 discloses a bit 1600 that may also be incorporated with the present invention. Fig. 19 discloses another drill bit 1600 typically used in horizontal drilling. The tool may be used in a trenching machine 2000 with a boom 2050, as shown in Fig. 20. Milling machines that may be used to reduce the size of rocks, grain, trash, natural resources, chalk, wood, tires, metal, cars, tables, couches, coal, minerals, chemicals, or other natural resources, may also be used with the present invention.

A jaw crusher 2100 such as shown in Fig. 21 may comprise a fixed plate 2150 with a wear surface and pivotal plate 2151 with another wear surface. Rock or other materials are reduced as they travel down the wear plates. The inserts may be fixed to the wear plates 2152 and may get larger closer to the pivotal end of the wear plate.

Hammer mills 2200 such as shown in Fig. 22 may incorporate the tool at on the distal end 2250 of the hammer bodies 2251. Vertical shaft impactors 2300, such as shown in Fig. 23, may also use the pointed inserts of superhard materials. They may use the pointed geometries on the targets or on the edges of a central rotor.

A cone crusher, as in the embodiment of Fig. 24, may also incorporate the pointed geometries of superhard material. The cone crusher may comprise a top and bottom wear plate 2650, 2651 that may incorporate the present invention.

Other applications not shown, but that may also incorporate the present invention include rolling mills; cleats; studded tires; ice climbing equipment; mulchers; jackbits; farming and snow plows; teeth in track hoes, back hoes, excavators, shovels; tracks, armor piercing ammunition; missiles; torpedoes; swinging picks; axes; jack hammers; cement drill bits; milling bits; drag bits; reamers; nose cones; and rockets. Fig. 25 is an orthogonal diagram of an embodiment of a tool 100 with a second segment 104, which is made of carbide and has a first volume. The first segment 103 is made of steel. The tool 100 comprises a first segment with a shank 101 suitable for attachment to a driving mechanism via a holder. The driving mechanism may be a drum used in pavement milling or mining. The first and second segments 103, 104 may be bonded to each other at interface 151. The second segment 104 may be bonded to the substrate 110 through a braze with a high palladium content, typically at least 30% palladium. The second segment 104 may comprise a first volume of .100 cubic inches to 2 cubic inches. Such a volume may be beneficial in absorbing impact stresses and protecting the rest of the tool 100 from wear. The carbide segment 104 and the substrate 110 may comprise a metal binder of tungsten, titanium, tantalum, molybdenum, niobium, cobalt and/or combinations thereof.

Further, the tool 100 may comprise a ratio of the length 152 of the second segment 104 to the length 153 of the whole attack tool which is 1/10 to 1/2; preferably the ratio is 1/7 to 1/2.5. The combination of the shank 101 and the first segment 103 may comprise a length 154 that is at least half of the tool's length 153.

Fig. 26 is an orthogonal diagram of an embodiment of a tool 100 with a second segment 104 with a second volume, which is less than the first volume. This may help to reduce the weight of the tool 100 which may require less horsepower to move or it may help to reduce the cost of the tool.

Fig. 27 is a diagram of a second segment 104 with a volume .100 to 2 cubic inches; preferably .350 to .550 cubic inches. The second segment 104 may comprise a height 152 of .2 inches to 2 inches; preferably .500 inches to .800 inches. The second segment 104 may comprise an upper cross- sectional thickness 155 of .250 to .750 inches; preferably the upper cross- sectional thickness 156 may be .300 inches to .500 inches. The second segment 104 may also comprise a lower cross- sectional thickness 155 of 1 inch to 1. 5 inches; preferably the lower cross- sectional thickness 155 may be 1.10 inches to 1.30 inches. The upper and lower cross- sectional thicknesses 156, 155 may be planar. The second segment 104 may also comprise a non- uniform cross- sectional thickness. Further, the second segment 104 may have features such as a chamfered edge 157 and a ledge 158 to optimize bonding and/or improve performance. Fig. 28 is an exploded perspective diagram of an embodiment of the tool 100. The braze material 159 between the second segment and the substrate 110 may comprising 30 to 62 weight percent of palladium. Preferably, this braze material 159 comprises 40 to 50 weight percent of palladium. The braze material 159 may comprise a melting temperature from 700 to 1200 degrees Celsius; preferably the melting temperature is from 800 to 970 degrees Celsius. This braze material 159 may comprise silver, gold, copper nickel, palladium, boron, chromium, silicon, germanium, aluminum, iron, cobalt, manganese, titanium, tin, gallium, vanadium, phosphorus, molybdenum, platinum, or combinations thereof. The braze material 159 may comprise 30 to 60 weight percent nickel, 30 to 62 weight percent palladium, and 3 to 15 weight percent silicon; preferably the braze material 159 may comprise 47.2 weight percent nickel, 46.7 weight percent palladium, and 6.1 weight percent silicon. Active cooling during brazing may be critical in some embodiments, since the heat from brazing may leave some residual stress in the bond between the substrate 110 and the superhard material 109. The substrate 110 may comprise a length of .1 to 2 inches. The superhard material 109 may be .020 to .100 inches away from the interface 200. The further away the superhard material 109 is from the interface the less thermal damage is likely to occur during brazing. Increasing the distance between the interface 200 and the superhard material 109, however, may increase the bending moment on the substrate 110 and increase stresses at the interface 200 upon impact.

An interface 151 between the first and second segments 103, 104 may comprise a second braze material 160 which may comprise a melting temperature from 800 to

1200 degrees Celsius. The second braze material 160 may comprise 40 to 80 weight percent copper, 3 to 20 weight percent nickel, and 3 to 45 weight percent manganese; preferably the second braze material 160 may comprise 67.5 weight percent copper, 9 weight percent nickel, and 23.5 weight percent manganese.

Fig. 29 is a diagram of a tool 100 with inserts 162 in the first segment 103 proximate the shank 101 wherein the insert 162 comprises a hardness greater than 60 HRc. The metal segment 103 may comprise a hardness of 40 to 50 HRc. The metal segment 103 and shank 101 may be made from the same piece of material.

The insert 162 may comprise a material selected from the group consisting of diamond, natural diamond, polycrystalline diamond, cubic boron nitride, vapor- deposited diamond, diamond grit, polycrystalline diamond grit, cubic boron nitride grit, chromium, tungsten, titanium, molybdenum, niobium, a cemented metal carbide, tungsten carbide, aluminum oxide, zircon, silicon carbide, whisker reinforced ceramics, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof with hardness greater than 60 HRc. Having an insert 162 that is harder than the metal segment 103 may decrease the wear on the metal segment 103. Inserts 162 may also aid in the tool's rotation. Tools 100, such as those incorporated in drums, often rotate within their holders upon impact which allows wear to occur evenly around the tool 100 and the tip 107. The inserts 162 may be angled such so that it cause the tool 100 to rotate within the bore of the holder.

Figs. 25-30 are diagrams of several embodiments of insert. The insert may comprise a generally circular shape, a generally rectangular shape, a generally annular shape, a generally spherical shape, a generally pyramidal shape, a generally conical shape, a generally arcurate shape, a generally asymmetric shape, or combinations thereof. The distal most surface 164 of the insert 162 may be flush with the surface 165 of the first segment 103, extend beyond this surface 165, be recessed into surface 165, or combinations thereof. An example of the insert 162 extending beyond the surface 165 of the first segment 103 is seen in if Fig. 31. Fig. 29 discloses generally rectangular inserts 166 that are aligned with a central axis 167 of the tool 100. Fig. 30 discloses an insert 162 comprising an axial length forming an angle 168 of 1 to 75 degrees with an axial length 169 of the tool 100. The inserts may be oblong.

Fig. 31 discloses a circular insert 170 bonded to a protrusion 171 formed in the first segment 103. Figs. 32-34 disclose segmented inserts 162 that may extend considerably around the metal segment's circumference 172. The angle formed by insert's axial length may also be 90 degrees from the tool's axial length.

Figs 35 and 36 are diagrams of embodiments of the shank 101. The shank 101 may comprise a wear- resistant surface 173 greater than 60 HRc. The shank 101 may comprise a cemented metal carbide, steel, manganese, nickel, chromium, titanium, or combinations thereof. If a shank 101 comprises a cemented metal carbide, the carbide may have a binder concentration of 4 to 35 weight percent. The binder may be cobalt.

The wear- resistant surface 173 may comprise a cemented metal carbide, chromium, manganese, nickel, titanium, hard surfacing, diamond, cubic boron nitride, polycrystalline diamond, vapor deposited diamond, aluminum oxide, zircon, silicon carbide, whisker reinforced ceramics, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof. The wear- resistant surface 173 may be bonded to the shank 101 though the processes of electroplating, cladding, electroless plating, thermal spraying, annealing, hard facing, applying high pressure, hot dipping, brazing, or combinations thereof. The wear resistant surface may be a coating with a thickness of .001 to .200 inches. The wear resistant surface of the shank 101 may be polished. The wear- resistant surface 173 may also comprise layers 174. A shank may comprise steel, surrounded by a layer of another material, such as tungsten carbide. There may be one or more intermediate layers 175 between the shank and the wear-resistant surface that may help the wear- resistant surface bond to the shank. The wear- resistant surface may also comprise a plurality of layers. The layers 174 may comprise different characteristics such as hardness, modulus of elasticity, strength, thickness, grain size, metal concentration, and weight. The wear-resistant surface may be chromium with a hardness of 65 to 75 HRc. Figs. 37 and 38 are orthogonal diagrams of embodiments of the first segment 103 and the shank 101. The shank 101 may comprise one or more grooves 175. The wear- resistant surface 173 may be disposed within a groove 175 formed in the shank 101. Grooves 175 may be beneficial in increasing the bond strength between the wear- resistant surface 173 and the shank 101. The bond may also be improved by swaging the wear- resistant surface 173 on the shank 101. Additionally, the wear-resistant surface 173 may comprise a non- uniform diameter. The non-uniform diameter may help hold a retaining member (not shown) while the tool is in use. The entire cross- sectional thickness 176 of the shank 101 may be harder than 60 HRc. In some embodiments, the shank 101 may be made of a solid cemented metal carbide, or other material comprising a hardness greater than 60 HRc.

Fig. 39 is an orthogonal diagram of another embodiment showing the shank 101. The wear-resistant surface 173 may be segmented. Wear-resistant surface segments 177 may comprise a height less than the height of the shank. Referring to Fig. 40, the spring sleeve 105 may comprise an inner surface 178 with a hardness greater than 58 HRc. In some embodiments, any surface of the sleeve 105 may comprise a hardness greater than 58 HRc. The hardness may be achieved by bonding a material comprising chromium, hard chrome, thin dense chrome, flash chrome, tungsten, tantalum, niobium, titanium, molybdenum, carbide, natural diamond, polycrystalline diamond, vapor deposited diamond, cubic boron nitride, aluminum oxide, zircon, silicon, whisker reinforced ceramics, TiN, AlNi, AlTiNi, TiAlN, CrN/CrC/(Mo, W)S2, TiN/TiCN, AlTiN/MoS2, TiAlN, ZrN, diamond impregnated carbide, diamond impregnated matrix, silicon bonded diamond, or combinations thereof to any of the surfaces of the sleeve 105. The sleeve 105 may comprise a lip 179 proximate an outer edge of the sleeve.

The lip 179 may extend beyond the opening 180 of the bore 181 of the holder 182. The washer 106 may be recessed such that the washer 106 fits over the lip 179, and so that the lip 179 and the washer 106 are both flush against a top surface of the holder 182. An intermediate layer may be used to improve the strength or the bond of the material bonded to the surface of the sleeve 105.

The material may line the sleeve 105 at any part which may come in contact with the washer 106, such as along upper or outer edges of the lip. The material may be added to the sleeve 105 by electroplating, electroless plating, cladding, hot dipping, galvanizing, thermal spraying chemical vapor deposition, thermal diffusion, or physical vapor deposition.. Material may also be added to an outer surface of the shank 101 by the same methods. In some embodiments, the shank 101 and the sleeve 105 may comprise the same composition of material, or they may comprise different compositions of material. Both surfaces may be polished.

Referring to Fig. 41, the material of the inner surface 178 of the bore 181 may be segmented. Segmented material 183 may be positioned such that they may direct any rotation of the tool. Segmented material 183 may be more cost effective than a continuous layer of material, while providing adequate protection from damaging forces. The material may be added to the inner or outer surfaces of the holder 182 by electroplating, electroless plating, cladding, hot dipping, galvanizing, or thermal spraying. The material may be disposed within recesses formed in the bore 181. A material may be flush with the bore 182 or it may extend into the bore 182.

In the embodiment of Fig. 42, as the degradation assembly 100 degrades a paved surface 184, the tool experiences forces 185 in both axial and lateral directions. These forces 185 may cause the tool 100 to rotate and move within the bore 181 of the holder 182. The rotation and movement cause various friction and vibratory effects on both the bore 181 of the holder 182 and the shank 101, which may damage the holder or tool and limit the life of the degradation assembly. A gap size 186 within the range of .002 to .015 inches is believed to allow the holder to maintain a firm grip on the shank and allow the tool 100 to rotate within the bore 181 of the holder 182 while limiting damaging effects on the shank 101 and the holder 182. It is believed that a tip 107 with a superhard coating 109 such as diamond will have a greater life than a traditional tip without diamond and that it will outlive the shank 101 if there is too large of a gap between sleeve 105 and shank 109. If the gap 186 is too small, the tool 100 will not be able to rotate. In some embodiments, the sleeve 105 may be press fit into place from either side of the holder 182 before the tool 100 is inserted. Preferably, the sleeve 105 protects the holder 182 from wearing.

Fig. 43 discloses the tip 107 comprising a carbide substrate 110 bonded to the superhard material 109 at an interface 200. In one aspect of the invention the carbide substrate 110 may comprise an end at the interface 200 with a tapered portion 190 leading to a flat portion 191. The central section 1192 of the superhard material 109 may comprise a first thickness 192 between .125 and .300 inches immediately over the flat portion 191 of the carbide substrate 110 while the peripheral section 193 of the superhard material 109 may comprise a second thickness 195 which is less than the first thickness 192 over the tapered portion 190 of the carbide substrate 110. Preferably, the superhard material 109 is a monolayer, but in other embodiments, the superhard material 109 may comprise a plurality of layers.

The flat portion 191 of the carbide substrate 110 which may effectively redistribute the load stresses across the interface 200 of the carbide substrate 110. The flat portion 191 may comprise a diameter 196 measuring 66% to 133% the first thickness 192 of the superhard material 109. In some embodiments, the flat portion 191 may comprise a diameter 196 measuring 75% to 125% the first thickness 192. In other embodiments the first thickness 192 is basically equal to the diameter 196. In some embodiments, a circumference 197 (or a perimeter) of the flat portion 191 may be chosen by placing the circumference 197 so that it intersects generally at an imaginary line 198 which line intersects the central axis 199 of the tip at the apex 202 and forms a generally 45 degrees angle with the central axis 199. In other embodiments, the imaginary line 198 falls within the area of the flat portion 191 generally encompassed by the circumference 197. The flat portion 191 may provide a larger surface area and help to diffuse load stresses on the carbide substrate 110. This may be particularly advantageous in helping to improve the overall durability of the insert especially where the concentration of the load stresses are focused at the apex 202 of the superhard material 109 and subsequently transferred to the carbide substrate 110. As a result the effective redistribution of such load stresses may assist to further reduce spalling or delamination of the superhard material 109.

It is believed that a load applied to the apex of the superhard material will induce a shock wave generally traveling at a 45 degrees in basically all azimuthal directions from the impact of the load. Preferably, the impact occurs proximate the apex and therefore the shock wave may travel basically along the imaginary line. Preferably, the shock wave reaches the interface between the superhard material and the substrate some where in the flat portion so that the shock wave may be loaded to a flat surface rather than on a point of a curved surface. The first thickness' relationship to the diameter of the flat may be critical. If the first thickness is too large than the shock wave may not hit the flat portion. On the other hand if the first thickness is too small, then the shock wave may not have enough room to distribute across the interface focusing too much of the shock wave to localized areas on the flat. If the focused shock wave is too high the bond at the interface may become compromised.

U.S. Patent Serial Number 11/469,229; which is herein incorporate by reference for all that it contains; discloses a process by which the superhard material of the present invention may be made. An assembly for HPHT processing has a can with an opening and a mixture disposed within the opening. The container may be comprised of metal or a metal alloy also have a stop off that may be disposed intermediate a cap and a first lid also comprising a second lid and a stop off which may be used to form the superhard material. A preformed carbide substrate may be disposed within the container adjacent and above a mixture which is disposed towards the base of the container. The mixture may comprise cubic boron nitride or diamond that is arranged in a monolayer or a plurality of layers comprised of different diamond grains having smaller or larger sizes ranging between 0.5 and 300 microns. The layers may be arranged substantially proportionate to the flat portion of the carbide substrate such that the layers are preformed to have substantially flat portion. In some embodiments the smaller diamond grains may be disposed towards the upper portion of the mixture and help to provide a generally harder surface. The larger diamond grains may be disposed closer to the carbide substrate and help to provide better elasticity in the superhard material. Better elasticity may reduce delamination or spalling of the superhard material at the ήterface, especially as the carbide substrate contracts when cooling after the container is later removed from the HPHT press.

A stop off may be disposed at the opposite end of the container from the mixture. The container and contents may then be heated to a cleansing temperature between 800⁰C and 1040⁰C for a first period of time between 15 and 60 minutes, which may allow the mixture to become substantially free of contaminants. The temperature may then be increased to a sealing temperature between 1000⁰C and 1200⁰C for another 2 and 25 minutes to melt the stop off and seal the container and the substantially free mixture within it before placing in the HPHT press.

While in the press under the HPHT conditions, the metal binder material may infiltrate from the carbide substrate into the mixture which may further assist to promote bonding at the interface. In some embodiments the infiltrated metal binder material may comprise a greater concentration adjacent the interface which gradually diminishes through the remainder of the superhard. The infiltrated metal binder material may also assist in providing elasticity in the superhard material at the interface and help to further reduce delamination from the carbide substrate during the cooling process after being formed in a HPHT press.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.

Claims

CLAIMSWhat is claimed is:

1. A high impact resistant tool, comprising a superhard material bonded to a cemented metal carbide substrate at a non- planar interface; the superhard material comprises a substantially pointed geometry with an apex comprising .050 to .160 inch radius; and the superhard material comprises a .100 to .500 inch thickness from the apex to the non-planar interface.

2. The tool of claim 1, wherein the substantially conical surface comprises a side which forms a 35 to 55 degree angle with a central axis of the tool.

3. The tool of claim 2, wherein the angle is substantially 45 degrees.

4. The tool of claim 1, wherein at the interface the substrate comprises a tapered surface starting from a cylindrical rim of the substrate and ending at an elevated flatted central region formed in the substrate.

5. The tool of claim 6, wherein the flatted region comprises a diameter of .125 to

.250 inches.

6. The tool of claim 1, wherein the radius is .900 to .110 inches.

7. The tool of claim 1, wherein the thickness from the apex to the non-planar interface is .125 to .275 inches.

8. The tool of claim 1, wherein the superhard material and the substrate comprise a total thickness of .200 to .700 inches from the apex to a base of the substrate.

9. The tool of claim 1, wherein a volume of the superhard material is 75 to 150 percent of a volume of the carbide substrate.

10. The tool of claim 1, wherein the superhard material is polished.

11. The tool of claim 1, wherein the substrate is brazed to an end of a carbide segment.

12. The tool of claim 11, wherein the braze comprises 30 to 62 weight percent of palladium

13. The tool of claim 11, wherein the carbide segment is press fit into a bore of a steel body.

14. The tool of claim 11, wherein the carbide segment is brazed to a steel body.

15. The tool of claim 14, wherein the steel body comprises a shank adapted to be received within a holder of a driving mechanism.

16. The tool of claim 15, wherein the shank received within the holder comprises a wear resistant surface harder than 58 HRc.

17. The tool of claim 15, wherein a spring sleeve is disposed within the bore of the holder and surrounds the shank such that there is a .002 to .015 gap between the sleeve and the shank.

18. The tool of claim 1, wherein the tool comprises the characteristic of withstanding impact greater than 80 joules.

19. The tool of claim 1, wherein the superhard material may be .020 to .100 inches away from a base of the substrate.

20. A pick, comprising: a tip with a superhard material bonded to a cemented metal carbide substrate at a non-planar interface; the superhard material comprises a substantially pointed geometry with an apex comprising .050 to .160 inch radius; the superhard material comprises a .100 to .500 inch thickness from the apex to the non-planar interface; and the tip comprising a height of less than .700 inches and being brazed to a carbide segment at a planar interface; and the carbide segment being substantially coaxial with and rotationally fixed to a shank which is secured within and adapted to rotate within a holder attached to a drum.