WO2014161816A2 - Constructions superdures et ses procédés de fabrication - Google Patents

Constructions superdures et ses procédés de fabrication Download PDF

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Publication number
WO2014161816A2
WO2014161816A2 PCT/EP2014/056458 EP2014056458W WO2014161816A2 WO 2014161816 A2 WO2014161816 A2 WO 2014161816A2 EP 2014056458 W EP2014056458 W EP 2014056458W WO 2014161816 A2 WO2014161816 A2 WO 2014161816A2
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WO
WIPO (PCT)
Prior art keywords
superhard
grains
phase
mass
polycrystalline
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Application number
PCT/EP2014/056458
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English (en)
Other versions
WO2014161816A3 (fr
Inventor
Valentine KANYANTA
Maweja Kasonde
Mehmet Serdar Ozbayraktar
Original Assignee
Element Six Abrasives S.A.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Element Six Abrasives S.A. filed Critical Element Six Abrasives S.A.
Priority to US14/778,448 priority Critical patent/US20160271757A1/en
Priority to CN201480028596.4A priority patent/CN105229255B/zh
Publication of WO2014161816A2 publication Critical patent/WO2014161816A2/fr
Publication of WO2014161816A3 publication Critical patent/WO2014161816A3/fr
Priority to US15/844,886 priority patent/US20180126516A1/en

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B24GRINDING; POLISHING
    • B24DTOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D18/00Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for
    • B24D18/0009Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for using moulds or presses
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/105Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing inorganic lubricating or binding agents, e.g. metal salts
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C26/00Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • E21B10/567Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • E21B10/567Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/5676Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts having a cutting face with different segments, e.g. mosaic-type inserts
    • EFIXED CONSTRUCTIONS
    • E21EARTH OR ROCK DRILLING; MINING
    • E21BEARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00Drill bits
    • E21B10/46Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56Button-type inserts
    • E21B10/567Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts
    • E21B10/573Button-type inserts with preformed cutting elements mounted on a distinct support, e.g. polycrystalline inserts characterised by support details, e.g. the substrate construction or the interface between the substrate and the cutting element
    • E21B10/5735Interface between the substrate and the cutting element
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F5/00Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
    • B22F2005/001Cutting tools, earth boring or grinding tool other than table ware
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/062Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts
    • B22F2007/066Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools involving the connection or repairing of preformed parts using impregnation

Definitions

  • This disclosure relates to superhard constructions and methods of making such constructions, particularly but not exclusively to constructions comprising polycrystalline diamond (PCD) structures attached to a substrate, and tools comprising the same, particularly but not exclusively for use in rock degradation or drilling, or for boring into the earth.
  • PCD polycrystalline diamond
  • Polycrystalline superhard materials such as polycrystalline diamond (PCD) and polycrystalline cubic boron nitride (PCBN) may be used in a wide variety of tools for cutting, machining, drilling or degrading hard or abrasive materials such as rock, metal, ceramics, composites and wood-containing materials.
  • tool inserts in the form of cutting elements comprising PCD material are widely used in drill bits for boring into the earth to extract oil or gas.
  • the working life of superhard tool inserts may be limited by fracture of the superhard material, including by spalling and chipping, or by wear of the tool insert.
  • Cutting elements such as those for use in rock drill bits or other cutting tools typically have a body in the form of a substrate which has an interface end/surface and a superhard material which forms a cutting layer bonded to the interface surface of the substrate by, for example, a sintering process.
  • the substrate is generally formed of a tungsten carbide-cobalt alloy, sometimes referred to as cemented tungsten carbide and the superhard material layer is typically polycrystalline diamond (PCD), polycrystalline cubic boron nitride (PCBN) or a thermally stable product TSP material such as thermally stable polycrystalline diamond.
  • PCD polycrystalline diamond
  • PCBN polycrystalline cubic boron nitride
  • TSP material such as thermally stable polycrystalline diamond
  • PCD Polycrystalline diamond
  • PCD material is an example of a superhard material (also called a superabrasive or ultra hard material) comprising a mass of substantially inter-grown diamond grains, forming a skeletal mass defining interstices between the diamond grains.
  • PCD material typically comprises at least about 80 volume % of diamond and is conventionally made by subjecting an aggregated mass of diamond grains to an ultra-high pressure of greater than about 5 GPa, and temperature of at least about 1 ,200°C, for example.
  • a material wholly or partly filling the interstices may be referred to as filler or binder material.
  • PCD is typically formed in the presence of a sintering aid such as cobalt, which promotes the inter-growth of diamond grains.
  • a sintering aid such as cobalt
  • Suitable sintering aids for PCD are also commonly referred to as a solvent-catalyst material for diamond, owing to their function of dissolving, to some extent, the diamond and catalysing its re-precipitation.
  • a solvent-catalyst for diamond is understood be a material that is capable of promoting the growth of diamond or the direct diamond-to-diamond inter-growth between diamond grains at a pressure and temperature condition at which diamond is thermodynamically stable. Consequently the interstices within the sintered PCD product may be wholly or partially filled with residual solvent-catalyst material.
  • PCD is often formed on a cobalt-cemented tungsten carbide substrate, which provides a source of cobalt solvent-catalyst for the PCD.
  • Materials that do not promote substantial coherent intergrowth between the diamond grains may themselves form strong bonds with diamond grains, but are not suitable solvent -catalysts for PCD sintering.
  • Cemented tungsten carbide which may be used to form a suitable substrate is formed from carbide particles being dispersed in a cobalt matrix by mixing tungsten carbide particles/grains and cobalt together then heating to solidify.
  • a superhard material layer such as PCD or PCBN
  • diamond particles or grains or CBN grains are placed adjacent the cemented tungsten carbide body in a refractory metal enclosure such as a niobium enclosure and are subjected to high pressure and high temperature so that inter-grain bonding between the diamond grains or CBN grains occurs, forming a polycrystalline superhard diamond or polycrystalline CBN layer.
  • the substrate may be fully cured prior to attachment to the superhard material layer whereas in other cases, the substrate may be green, that is, not fully cured. In the latter case, the substrate may fully cure during the HTHP sintering process.
  • the substrate may be in powder form and may solidify during the sintering process used to sinter the superhard material layer.
  • PCD polycrystalline diamond
  • PCD polycrystalline diamond
  • a superhard polycrystalline construction comprising:
  • a body of polycrystalline superhard material comprising:
  • first superhard phase having a first average grain size
  • second superhard phase having a second average grain size
  • the second superhard phase is located in one or more channels or apertures in the first superhard phase, the first superhard phase forming a skeleton in the body of superhard material, the second superhard phase beingand bonded thereto the first superhard phase by a non- superhard phase;
  • first superhard phase differs from the second superhard phase in average grain size and/or composition.
  • a method of forming a superhard polycrystalline construction comprising: providing a first mass of particles or grains of superhard material for forming a first superhard phase; sintering the first superhard phase and forming a skeleton having a plurality of channels and/or apertures therein; providing a second mass of superhard grains or particles for forming a second superhard phase;
  • the second mass of superhard grains or particles in one or more channels and/or apertures in the skeleton formed of the first superhard phase to form a pre-sinter assembly; wherein the first superhard phase differs from the second superhard phase in average grain size and/or composition;
  • the pre-sinter assembly in the presence of a catalyst/solvent material for the superhard grains at an ultra-high pressure of around 5.5 GPa or greater and a temperature at which the superhard material is more thermodynamically stable than graphite to sinter together the grains of superhard material to form a polycrystalline superhard construction, the superhard grains exhibiting inter-granular bonding and defining a plurality of interstitial regions therebetween, wherein the body of polycrystalline superhard material comprises a working surface, the working surface being formed of alternating portions of the skeleton and the second superhard phase located in the plurality of channels and/or apertures in the skeleton.
  • a tool comprising the superhard polycrystalline construction defined above, the tool being for cutting, milling, grinding, drilling, earth boring, rock drilling or other abrasive applications.
  • the tool may comprise, for example, a drill bit for earth boring or rock drilling, a rotary fixed-cutter bit for use in the oil and gas drilling industry, or a rolling cone drill bit, a hole opening tool, an expandable tool, a reamer or other earth boring tools.
  • a drill bit or a cutter or a component therefor comprising the superhard polycrystalline construction defined above.
  • Figure 1 is a schematic perspective view of an example PCD cutter element for a drill bit for boring into the earth;
  • Figure 2 is a plan view of an example of a PCD cutter element
  • Figure 3 is a schematic flow diagram of the process of forming an example PCD cutter element such as that shown in Figure 2;
  • Figure 4 is a schematic partial cross-section through a further example of a PCD cutter element
  • Figure 5a is a schematic partial cross-section through a still further example of a PCD cutter element
  • Figure 5b is a plan view of a further example of a PCD cutter element.
  • Figure 6 is a plot showing the results of a vertical borer test comparing two conventional PCD cutters with differing average diamond grain sizes with the PCD cutter element shown in Figure 2.
  • a "superhard material” is a material having a Vickers hardness of at least about 28 GPa.
  • Diamond and cubic boron nitride (cBN) material are examples of superhard materials.
  • a "superhard construction” means a construction comprising a body of polycrystalline superhard material.
  • a substrate may be attached thereto or alternatively the body of polycrystalline material may be free-standing and unbacked.
  • polycrystalline diamond is a type of polycrystalline superhard (PCS) material comprising a mass of diamond grains, a substantial portion of which are directly inter-bonded with each other and in which the content of diamond is at least about 80 volume percent of the material.
  • interstices between the diamond grains may be at least partly filled with a binder material comprising a catalyst for diamond.
  • interstices or "interstitial regions” are regions between the diamond grains of PCD material.
  • interstices or interstitial regions may be substantially or partially filled with a material other than diamond, or they may be substantially empty.
  • PCD material may comprise at least a region from which catalyst material has been removed from the interstices, leaving interstitial voids between the diamond grains.
  • a "catalyst material" for a superhard material is capable of promoting the growth or sintering of the superhard material.
  • substrate as used herein means any substrate over which the superhard material layer is formed.
  • a “substrate” as used herein may be a transition layer formed over another substrate.
  • integrated regions or parts are produced contiguous with each other and are not separated by a different kind of material.
  • a cutting element 1 includes a substrate 10 with a layer of superhard material 12 formed on the substrate 10.
  • the substrate 10 may be formed of a hard material such as cemented tungsten carbide.
  • the superhard material 12 may be, for example, polycrystalline diamond (PCD), or a thermally stable product such as thermally stable PCD (TSP).
  • the cutting element 1 may be mounted into a bit body such as a drag bit body (not shown) and may be suitable, for example, for use as a cutter insert for a drill bit for boring into the earth.
  • the exposed top surface of the superhard material opposite the substrate forms the cutting face 14, which is the surface which, along with its edge 16, performs the cutting in use.
  • the substrate 10 is generally cylindrical and has a peripheral surface 20 and a peripheral top edge 22.
  • a PCD grade is a PCD material characterised in terms of the volume content and size of diamond grains, the volume content of interstitial regions between the diamond grains and composition of material that may be present within the interstitial regions.
  • a grade of PCD material may be made by a process including providing an aggregate mass of diamond grains having a size distribution suitable for the grade, optionally introducing catalyst material or additive material into the aggregate mass, and subjecting the aggregated mass in the presence of a source of catalyst material for diamond to a pressure and temperature at which diamond is more thermodynamically stable than graphite and at which the catalyst material is molten.
  • molten catalyst material may infiltrate from the source into the aggregated mass and is likely to promote direct intergrowth between the diamond grains in a process of sintering, to form a PCD structure.
  • the aggregate mass may comprise loose diamond grains or diamond grains held together by a binder material and said diamond grains may be natural or synthesised diamond grains.
  • Different PCD grades may have different microstructures and different mechanical properties, such as elastic (or Young's) modulus E, modulus of elasticity, transverse rupture strength (TRS), toughness (such as so-called KiC toughness), hardness, density and coefficient of thermal expansion (CTE).
  • Different PCD grades may also perform differently in use. For example, the wear rate and fracture resistance of different PCD grades may be different.
  • All of the PCD grades may comprise interstitial regions filled with material comprising cobalt metal, which is an example of catalyst material for diamond.
  • the PCD structure 12 may comprise one or more PCD grades.
  • FIG 2 is a plan view of an embodiment of PCD material forming the super hard layer 12 of Figure 1 .
  • the superhard layer 12 comprises a first phase of superhard material forming a skeleton or framework 100 which, in the example in Figure 2, is in the form of a spoked disc or section with spokes extending from a central hub section, and a second superhard phase 120 located between adjacent spokes.
  • the superhard material of the first and second phases 100, 200 may be comprised of inter-bonded grains of superhard material such as, for example, diamond grains or particles.
  • the starting mixture prior to sintering may be unimodal or multimodal, for example, bimodal, that is, the feed comprises a mixture of a coarse fraction of diamond grains and a fine fraction of diamond grains which are to form one or more of the alternating layers or strata.
  • the coarse fraction may have, for example, an average particle/grain size ranging from about 10 to 60 microns.
  • average particle or grain size it is meant that the individual particles/grains have a range of sizes with the mean particle/grain size representing the "average”.
  • the average particle/grain size of the fine fraction is less than the size of the coarse fraction, for example between around 1/10 to 6/10 of the size of the coarse fraction, and may, in some embodiments, range for example between about 0.1 to 20 microns.
  • the weight ratio of the coarse diamond fraction to the fine diamond fraction ranges from about 50% to about 97% coarse diamond and the weight ratio of the fine diamond fraction may be from about 3% to about 50%. In other embodiments, the weight ratio of the coarse fraction to the fine fraction will range from about 70:30 to about 90:10.
  • the weight ratio of the coarse fraction to the fine fraction may range for example from about 60:40 to about 80:20.
  • the particle size distributions of the coarse and fine fractions do not overlap and in some embodiments the different size components of the compact are separated by an order of magnitude between the separate size fractions making up the multimodal distribution.
  • Some embodiments may comprise a wide bi-modal size distribution between the coarse and fine fractions of superhard material, but some embodiments may include three or even four or more size modes which may, for example, be separated in size by an order of magnitude, for example, a blend of particle sizes whose average particle size is 20 microns, 2 microns, 200nm and 20nm. Sizing of diamond particles/grains into fine fraction, coarse fraction, or other sizes in between, may be through known processes such as jet-milling of larger diamond grains and the like.
  • the diamond grains used to form the polycrystalline diamond material may be natural or synthetic.
  • the binder catalyst/solvent may comprise cobalt or some other iron group elements, such as iron or nickel, or an alloy thereof.
  • Carbides, nitrides, borides, and oxides of the metals of Groups IV-VI in the periodic table are other examples of non-diamond material that might be added to the sinter mix.
  • the binder/catalyst/sintering aid may be Co.
  • the cemented metal carbide substrate may be conventional in composition and, thus, may be include any of the Group IVB, VB, or VIB metals, which are pressed and sintered in the presence of a binder of cobalt, nickel or iron, or alloys thereof.
  • the metal carbide is tungsten carbide.
  • the cutter of Figure 1 may be fabricated, for example, as shown in the flow diagram of Figure 3.
  • a “green body” is a body comprising grains to be sintered and a means of holding the grains together, such as a binder, for example an organic binder.
  • the mesostructure of the PCD element 200 shown as being prepared in Figure 3 is comprised of two PCD phases, the first phase having a first diamond particle size distribution and the second phase having a different diamond particle size distribution.
  • the different particle size distributions may in turn be unimodal, comprising a single grade of diamond grains, or multimodal comprising two or more different grades of diamond grains or particles.
  • Each material grade powder is prepared separately by ball milling to produce the particle size distribution of interest.
  • the individual powders may be mixed by ball milling with a catalyst binder such as, for example, Co, Ni, Fe, Mn, Pt, and Ir and/or combinations thereof. In some embodiments, no additional catalyst binder is included in this manner.
  • diamond powder of one diamond grain size grade is sintered by cobalt infiltration from a WC substrate at high pressure, preferably above 5 GPa, and high temperature, preferably above 1400 deg Celsius.
  • powder of one grade of diamond may be sintered as a solid PCD without infiltration. This is achievable by, for example, third- generation admixing.
  • One or more discs of sintered PCD which are to form the skeleton or framework in the PCD table 12 may be prepared as above.
  • the disc(s) is/are then polished and engineered slots or apertures are cut in the PCD disc(s) to produce the desired skeleton mesostructure or framework 200 using, for example, an EDM process, laser abrasion or ablation, or a die sinking process.
  • the slots or apertures in the skeleton 200 may take any shape, as desired for the particular application, such as, for example, circular, square, rectangular, or polygonal or a mixture thereof.
  • the skeleton 200 is introduced into a niobium cup.
  • a powder mix of the second phase material 300 such as diamond powder, diamond shredded paper, or, for example, diamond slurry in inert liquid, is placed into the cup to fill the open volumes in the skeleton 200 and to form an interface with a substrate 320 which is placed on top of the assembly to form a pre-composite.
  • the substrate 320 may be, for example, a composite of WC, or alumina, and may include a sintering catalyst such as Co, Ni, Fe, or Mn, for example, which will infiltrate the skeleton during HPHT sintering.
  • the pre-composite is then consolidated to increase the green body density by methods such as vibration compaction, cold isostatic pressing, or HIP.
  • the binder materials may be removed from the pre- composites by heat treatment at 650C in an 5%H2/N2 atmosphere.
  • the pre-composites may then be outgassed at, for example, 1050C under vacuum (10 "5 mbar).
  • the pre-composite is then sintered in an HPHT process at a temperature of around 1400C and a pressure of, for example, greater than 5GPa to form a PCD compact such as that shown in Figure 1 .
  • a slurry of diamond or superhard material powder is prepared in a mixture of alcohol such as methanol or ethanol and a plasticizer such as DBP. The slurry is then homogenised in a tubular mixer.
  • a paper of diamond or superhard material is prepared by casting on a moving table and dried at about 60C. The paper thickness may be, for example, 200 micrometres or less.
  • a male structure reproducing the desired mesostructure is formed on a solid punch, made of, for example, WC, hardened steel or any high strength material. The punch is used to create the open spaces/volumes in individual papers which are to form the mesostructure. A number of individual perforated papers are stacked together to produce a skeleton mesostructure of required thickness.
  • a green body skeleton of one diamond grade, with a desired mesostructure is injection moulded or 3D printed using an appropriate binder.
  • the open volumes in the skeleton may take any shape, such as, for example, circular, square, rectangular, or polygonal, or any desired combination thereof.
  • the skeleton is then placed in a niobium cup and the method described above for filling the voids in the mesostructure and sintering to form the PCD compact are followed.
  • the skeleton may be formed as follows.
  • a male green body skeleton of one diamond graded, with a desired mesostructure is injection moulded or 3D printed using an appropriate binder.
  • a female green body skeleton of one diamond grade, with a desired mesostructure is injection moulded or 3D printed using an appropriate binder.
  • the open volumes in the skeleton may take any shape, such as circular, square, rectangular, and polygonal or any combination thereof.
  • the male and female parts are assembled, placed on top of a WC-catalyst substrate in a niobium cup as described in the methods above and the pre- composite is sintered at HPHT, for example at a temperature of above 1400C and pressure above 5GPa.
  • the skeleton may be prepared as follows.
  • a green body with a desired mesostructure consisting of alternating material phases is 3D printed using an appropriate binder.
  • Alternating material phases may be, for example, PCD of different grades, PCD and an oxide or ceramic or WC or any other hard metal.
  • the green body is placed on top of a pre-formed WC-catalyst substrate and sintered at HPHT as described above.
  • the skeleton or framework 100, 200 is pre- sintered, the skeleton may be subjected to a treatment such as acid leaching, to remove residual catalyst/binder from some or substantially all of the interstices between the inter-bonded diamond grains to reduce the catalyst content therein.
  • the starting skeleton disc 100, 200 may be made of a more abrasive and high impact resistance PCD grade (or material) 300 than that used to fill the voids or channels in the skeleton, or vice-versa, as desired depending on the intended application of the sintered PCD compact, the empty volumes of the skeleton disc being filled with, for example, a diamond powder grade different in composition and/or particle size from that used in the starting skeleton green body to achieve the desired construction.
  • the starting skeleton disc may also be prepared as a green body using 3D printing or injection moulding. In this case, the insert only goes through one HPHT sintering cycle.
  • the skeleton 100, 200 may be formed of one or more layers or stacked discs having any desired combination of voids or channels formed therein, aligned in a particular chosen configuration.
  • Figures 2, 4, 5a and 5b show alternative configurations for the skeleton, the configuration shown in Figure 2 being that of a spoked structure such that, in the final sintered product, the body of superhard material comprises alternating sectors which may be, for example, concentric vertical layers as shown in Figure 2, which may, in other embodiments, be inclined with respect to the vertical axis as shown in Figure 4 or regions as shown in Figures 5a an 5b.
  • the alternating sectors, layers or regions are bonded together by infiltration and reaction with a catalyst material during a high pressure high temperature sintering.
  • embodiments of either the skeleton 100, 200 and/or the second superhard phase 300 filling the voids or channels in the skeleton may be made by a number methods of preparing a green body.
  • the green body or bodies comprise(s) grains or particles of superhard material, and a binder, such as an organic binder.
  • the green body or bodies may also comprise catalyst material for promoting the sintering of the superhard grains.
  • the green body or bodies may be made by combining the grains or particles with the binder and forming them into a body having substantially the same general shape as that of the intended sintered body, whether that be the skeleton or second superhard phase which is to fill the channels or voids in the skeleton, and drying the binder. At least some of the binder material may be removed by, for example, burning it off.
  • the green body may be formed by a method including a compaction process, injection or other methods such as molding, extrusion, deposition modelling methods.
  • the substrate 320 may provide a source of catalyst material for promoting the sintering of the superhard grains.
  • the superhard grains may be diamond grains and the substrate may be cobalt-cemented tungsten carbide, the cobalt in the substrate being a source of catalyst for sintering the diamond grains.
  • the pre-sinter assembly may comprise an additional source of catalyst material.
  • the polycrystalline super hard constructions may be ground to size and may include, if desired, a 45° chamfer of approximately 0.4mm height on the body of polycrystalline super hard material so produced.
  • solvent / catalyst material may be included or introduced into the aggregated mass of diamond grains from a source of the material other than the cemented carbide substrate.
  • the solvent / catalyst material may comprise cobalt that infiltrates from the substrate in to the aggregated mass of diamond grains just prior to and during the sintering step at an ultra-high pressure.
  • an alternative source may need to be provided in order to ensure good sintering of the aggregated mass to form PCD.
  • Solvent / catalyst for diamond may be introduced into the aggregated mass of diamond grains by various methods, including blending solvent / catalyst material in powder form with the diamond grains, depositing solvent / catalyst material onto surfaces of the diamond grains, or infiltrating solvent / catalyst material into the aggregated mass from a source of the material other than the substrate, either prior to the sintering step or as part of the sintering step.
  • Methods of depositing solvent / catalyst for diamond, such as cobalt, onto surfaces of diamond grains are well known in the art, and include chemical vapour deposition (CVD), physical vapour deposition (PVD), sputter coating, electrochemical methods, electroless coating methods and atomic layer deposition (ALD). It will be appreciated that the advantages and disadvantages of each depend on the nature of the sintering aid material and coating structure to be deposited, and on characteristics of the grain.
  • the bonder/catalyst such as cobalt may be deposited onto surfaces of the diamond grains by first depositing a pre-cursor material and then converting the precursor material to a material that comprises elemental metallic cobalt.
  • cobalt carbonate may be deposited on the diamond grain surfaces using the following reaction: Co(NO 3 ) 2 + Na 2 CO 3 -> C0CO3 + 2NaNO 3
  • the deposition of the carbonate or other precursor for cobalt or other solvent / catalyst for diamond may be achieved by means of a method described in PCT patent publication number WO/2006/032982.
  • the cobalt carbonate may then be converted into cobalt and water, for example, by means of pyrolysis reactions such as the following:
  • cobalt powder or precursor to cobalt such as cobalt carbonate
  • cobalt carbonate may be blended with the diamond grains.
  • a precursor to a solvent / catalyst such as cobalt
  • the cemented carbide substrate may be formed of tungsten carbide particles bonded together by the binder material, the binder material comprising an alloy of Co, Ni and Cr.
  • the tungsten carbide particles may form at least 70 weight percent and at most 95 weight percent of the substrate.
  • the binder material may comprise between about 10 to 50 wt.% Ni, between about 0.1 to 10 wt.% Cr, and the remainder weight percent comprises Co.
  • a PCD compact according to an embodiment comprising a skeleton or framework 100, 200 formed of PCD having an average diamond grain size of around 4 microns and voids filled with PCD 300 having an average diamond grain sixe of around 22 microns was compared in a vertical boring mill test with two conventional PCD cutters formed of diamond having an average grain size of around 4 microns (FG302) and two PCD cutters formed of diamond having an average grain size of around 22 microns (Quadmodal).
  • the results are shown graphically in Figure 6.
  • the results of the test on the PCD embodiment is the middle line in Figure 6. In this test, the wear flat area was measured as a function of the number of passes of the cutter element boring into the workpiece. The results provide an indication of the total wear scar area plotted against cutting length.
  • the PCD compact formed according to an embodiment was able to achieve a greater cutting length and smaller wear scar area than that occurring in the conventional PCD formed of diamond having an average grain size of 22 microns, and a greater cutting length and similar wear scar to the conventional PCD compacts formed of diamonds having a fine grain size of around 4 microns. This means that a longer working life of the tool having an embodiment cutter is possible for similar wear scar formation.
  • the functionally graded PCD of embodiments with alternating superabrasive phases between the skeleton which has been double-sintered and the superabrasive material in the voids or channels of the skeleton or framework, enables the combination of the high abrasion resistance of one material phase with the high impact resistance of the other resulting in a PCD material with a combination of good abrasion, fracture and impact resistance.
  • alternating the single sintered and double sintered boundaries by filling voids or channels in the skeleton which has been double-sintered with a superhard phase that has only been through a single sintering stage may assist in inhibiting the growth of flaws initiated in the first sintering process during the second sintering process, which could otherwise lead to cracks in use, and/or may assist in inhibiting the initiation of cracks during use.
  • the effect of thermal expansion of the skeleton or framework during the second sintering process is believed to be controlled by the presence of the unsintered second superhard phase which is first sintered during the second sintering phase. This is also believed to assist in inhibiting cracks from initiating during use as residual stresses in the PCD compact 10 may be favourably controlled.
  • the PCD elements 10 described with reference to Figures 1 and 2 may be processed by grinding to modify their shape.
  • catalyst material may be removed from a region of the PCD structure adjacent the working surface or the side surface or both the working surface and the side surface. This may be done by treating the PCD structure with acid to leach out catalyst material from between the diamond grains, or by other methods such as electrochemical methods.
  • a thermally stable region which may be substantially porous, extending a depth of at least about 50 microns or at least about 100 microns from a surface of the PCD structure, may thus be provided.
  • the leaching depth in alternating sectors, layers or regions will be different due to different microstructures. This may be used to achieve a preferred leached profile.
  • the PCD body in the structure of Figures 1 and 2 comprising a PCD structure bonded to a cemented carbide support body may be created or finished to provide a PCD element which is substantially cylindrical and having a substantially planar working surface, or a generally domed, pointed, rounded conical or frusto-conical working surface.
  • the PCD element may be suitable for use in, for example, a rotary shear (or drag) bit for boring into the earth, for a percussion drill bit or for a pick for mining or asphalt degradation.
  • one or more different manufacturing methods may be used, including but not limited to EDM cutting and sintering of pre-sintered PCD inserts, injection moulding or 3D printing of green parts.
  • the pre-sintered skeleton/perforated disc containing one PCD grade may be prepared by EDM cutting or laser abrasion or ablation and used in second stage sintering where a different PCD grade may be used to fill the empty volumes in the skeleton PCD disc.
  • the result is a functionally graded PCD material with alternating PCD phases of different PCD grades.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Geochemistry & Mineralogy (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Inorganic Chemistry (AREA)
  • Earth Drilling (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)
  • Powder Metallurgy (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

L'invention concerne une construction polycristalline superdure comprenant un corps de matériau superdur polycristallin comprenant une première phase superdure ayant une première taille de grain moyenne; et une seconde phase superdure ayant une seconde taille de grain moyenne. La seconde phase superdure est située dans un ou plusieurs canaux ou ouvertures dans la première phase superdure, la première phase superdure formant un squelette dans le corps de matériau superdur. La seconde phase superdure est liée à la première phase superdure par une phase non superdure et la première phase superdure diffère de la seconde phase superdure en taille de grain moyenne et/ou en composition. Un procédé de fabrication d'une construction polycristalline superdure est également décrit.
PCT/EP2014/056458 2013-03-31 2014-03-31 Constructions superdures et ses procédés de fabrication WO2014161816A2 (fr)

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WO2016062618A3 (fr) * 2014-10-21 2016-06-16 Element Six (Uk) Limited Constructions extra-dures et leurs procédés de production
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WO2017114675A1 (fr) * 2015-12-31 2017-07-06 Element Six (Uk) Limited Constructions extra-dures et leurs procédés de fabrication
WO2017114677A1 (fr) * 2015-12-31 2017-07-06 Element Six (Uk) Limited Structures superdures et leurs procédés de fabrication
GB2559479A (en) * 2016-12-31 2018-08-08 Element Six Uk Ltd Superhard constructions & methods of making same
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CN105229255B (zh) 2020-02-14
GB2514894B (en) 2016-01-27
WO2014161816A3 (fr) 2015-03-19
CN105229255A (zh) 2016-01-06
GB201305873D0 (en) 2013-05-15
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GB201405731D0 (en) 2014-05-14
US20160271757A1 (en) 2016-09-22

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