EP0865876B1 - Abrading method - Google Patents

Abrading method Download PDF

Info

Publication number
EP0865876B1
EP0865876B1 EP98301942A EP98301942A EP0865876B1 EP 0865876 B1 EP0865876 B1 EP 0865876B1 EP 98301942 A EP98301942 A EP 98301942A EP 98301942 A EP98301942 A EP 98301942A EP 0865876 B1 EP0865876 B1 EP 0865876B1
Authority
EP
European Patent Office
Prior art keywords
diamond
abrading
workpiece
compact
wood
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
EP98301942A
Other languages
German (de)
French (fr)
Other versions
EP0865876A3 (en
EP0865876A2 (en
Inventor
Klaus Tank
Robert Fries
Jurgen Dietrich Eckert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Element Six Pty Ltd
Original Assignee
De Beers Industrial Diamond Division Pty Ltd
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.)
Filing date
Publication date
Application filed by De Beers Industrial Diamond Division Pty Ltd filed Critical De Beers Industrial Diamond Division Pty Ltd
Publication of EP0865876A2 publication Critical patent/EP0865876A2/en
Publication of EP0865876A3 publication Critical patent/EP0865876A3/en
Application granted granted Critical
Publication of EP0865876B1 publication Critical patent/EP0865876B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D99/00—Subject matter not provided for in other groups of this subclass
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
    • B24B19/00—Single-purpose machines or devices for particular grinding operations not covered by any other main group
    • B24B19/22—Single-purpose machines or devices for particular grinding operations not covered by any other main group characterised by a special design with respect to properties of the material of non-metallic articles to be ground
    • B24B19/24—Single-purpose machines or devices for particular grinding operations not covered by any other main group characterised by a special design with respect to properties of the material of non-metallic articles to be ground of wood, e.g. furniture
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/04—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic
    • B24D3/06—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements
    • B24D3/08—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic metallic or mixture of metals with ceramic materials, e.g. hard metals, "cermets", cements for close-grained structure, e.g. using metal with low melting point
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C26/00—Alloys containing diamond or cubic or wurtzitic boron nitride, fullerenes or carbon nanotubes

Definitions

  • This invention relates to a method of abrading a workpiece in a corrosive environment, as per the preamble of claim 1.
  • An example of such a method is disclosed in EP-A-583 916.
  • Abrasive compacts are well known in the art and are used extensively in industry for the abrading of various workpieces. They consist essentially of a mass of abrasive particles present in an amount of at least 70 percent, preferably 80 to 90 percent, by volume of the compact bonded into a hard polycrystalline conglomerate.
  • the abrasive particles are either diamond or cubic boron nitride.
  • Abrasive compacts may be used on their own or bonded to a suitable substrate.
  • the substrate will generally be a cemented carbide substrate.
  • Diamond abrasive compacts have been used in a wide variety of abrading operations. These compacts may be produced using a second phase or bonding matrix which often contains a solvent/catalyst suitable for synthesising diamond.
  • a second phase or bonding matrix which contains chromium and a second metal selected from the group nickel, iron and cobalt.
  • the chromium is present in the form of the metal, chromium carbide and/or in the form of an intermetallic compound with the second metal.
  • the second metal is present in the form of the metal and/or the intermetallic compound referred to above.
  • the compact is useful in dressing tools or surface set drill bits.
  • the abrasive compact is used and is not supported by a cemented carbide substrate.
  • Diamond abrasive compacts have been used in the abrading, e.g. cutting, of wood products.
  • the hardness and abrasion resistance of a diamond compact are properties which are very useful in this application.
  • the wood or wood products may contain resins and a whole range of organic binders which remain on the diamond table and have to be cleaned with corrosive cleaning products that leach the cobalt binder before EDM re-sharpening can commence.
  • the loss of cobalt binder leads to undercutting when the cutting edge is EDM sharpened. This in turn leads to chipping of the cutting edge.
  • EP-A-0 583 916 discloses a method of producing an abrasive product comprising the steps of providing a mixture of diamond and discrete carbide particles, the diamond particles being smaller than the carbide particles and present in the mixture in an amount of more than 50 percent by volume, and subjecting the mixture to diamond synthesis conditions in the presence of a binder metal such as cobalt, nickel or iron.
  • the abrasive product thus produced has a substantial amount of direct diamond-to-diamond bonding and many of the characteristics of a diamond compact, but improved impact resistance due to the presence of the carbide particles.
  • the abrasive product has particular application in the machining of wood products such as natural wood, chipboard, fibreboard and hardboard.
  • the present invention describes a method of abrading a workpiece in a corrosive environment as per claim 1.
  • the diamond abrasive compact which is used in the invention is one which is a polycrystalline mass of diamond having a second phase, the diamond content of the compact comprising at least 70 percent by volume of the compact.
  • the second phase consists of chromium and nickel with any other components being in trace amounts only. It has been found that such diamond compacts have excellent corrosion resistance, particularly in environments in which there is present binder and/or corrosive cleaning chemicals.
  • the cutting point or edge on the compact is advanced into workpiece with an abrading action.
  • Abrading in the context of the specification means cutting, drilling, routing, polishing, or any similar such abrading action. This action may take various forms, known in the art, such as rotation of the cutting edge or point, reciprocating movement of the cutting edge or point or the like. Of course, the abrading action can also be achieved by maintaining the edge or point stationary and moving the workpiece.
  • the invention provides, according to another aspect, the use of a diamond abrasive compact as defined above in a method of abrading a workpiece in a corrosive environment.
  • the mass ratio of chromium to nickel metal will typically be 10:90 to 25:75.
  • the chromium and nickel will both exist in the form of the metal, in the form of carbides and/or in the form of an intermetallic compound of the chromium and the nickel.
  • the diamond abrasive compact has been found to have excellect corrosion resistance in environments in which there is present binder and/or corrosive cleaning chemicals.
  • the diamond abrasive compact may be bonded to a cemented carbide substrate or to a metal layer base such as molybdenum, tantalum or tungsten.
  • the invention has been found to have particular application in the abrading of products which contain wood.
  • wood products are natural wood, either soft or hard wood, laminated and non-laminated chipboard and fibreboard, which contain wood chips or fibre bonded by means of binders, hardboard which is compressed fibre and sawdust and plywood.
  • the wood products may have plastic or other coating applied to them.
  • Some of these wood products may contain resins and organic binders. It has been found that the presence of the corrosive cleaning chemicals and/or binder does not result in any significant undercutting of the cutting edge or point of a diamond abrasive compact as described above, leading to a much lower incidence of chipping.
  • the abrading may take the form of sawing, milling or profile cutting.
  • the tools which are used in such applications are generally multi-tip rotary tools such as circular saws, profile cutters, end mills, milling cutters and routers.
  • a mass of diamond particles (16,0g) was placed in a tantalum cup.
  • a disc (2,6g) of a nickel/chromium alloy was placed on top of the mass of diamonds.
  • the mass ratio of nickel/chromium was 80:20.
  • the nickel/chromium constituted 14 percent by mass of the contents of the loaded tantalum cup.
  • the loaded cup was placed in the reaction zone of a conventional high temperature/high pressure apparatus and subjected to 1500°C temperature and 5,5GPa (55 kilobars) pressure and these conditions were maintained for a period of 10 minutes.
  • Recovered from the reaction zone was a disc-shaped abrasive body which comprised a polycrystalline mass of diamond particles having a second phase containing chromium and nickel, as metals and in various combined forms, uniformly distributed through the diamond mass.

Abstract

A diamond abrasive compact is used for abrading a workpiece in a corrosive environment. The invention has particular application to abrading wood products which contain resins or organic binders. The diamond abrasive compact is characterised by a second phase which comprises chromium and nickel.

Description

    BACKGROUND OF THE INVENTION
  • This invention relates to a method of abrading a workpiece in a corrosive environment, as per the preamble of claim 1. An example of such a method is disclosed in EP-A-583 916.
  • Abrasive compacts are well known in the art and are used extensively in industry for the abrading of various workpieces. They consist essentially of a mass of abrasive particles present in an amount of at least 70 percent, preferably 80 to 90 percent, by volume of the compact bonded into a hard polycrystalline conglomerate. The abrasive particles are either diamond or cubic boron nitride.
  • Abrasive compacts may be used on their own or bonded to a suitable substrate. The substrate will generally be a cemented carbide substrate.
  • Diamond abrasive compacts have been used in a wide variety of abrading operations. These compacts may be produced using a second phase or bonding matrix which often contains a solvent/catalyst suitable for synthesising diamond. One such compact is described in EP-A-0 198 653. This compact is characterised by a second phase or bonding matrix which contains chromium and a second metal selected from the group nickel, iron and cobalt. The chromium is present in the form of the metal, chromium carbide and/or in the form of an intermetallic compound with the second metal. The second metal is present in the form of the metal and/or the intermetallic compound referred to above. In particular, the compact is useful in dressing tools or surface set drill bits. The abrasive compact is used and is not supported by a cemented carbide substrate.
  • Diamond abrasive compacts have been used in the abrading, e.g. cutting, of wood products. The hardness and abrasion resistance of a diamond compact are properties which are very useful in this application. The wood or wood products may contain resins and a whole range of organic binders which remain on the diamond table and have to be cleaned with corrosive cleaning products that leach the cobalt binder before EDM re-sharpening can commence. The loss of cobalt binder leads to undercutting when the cutting edge is EDM sharpened. This in turn leads to chipping of the cutting edge.
  • EP-A-0 583 916 discloses a method of producing an abrasive product comprising the steps of providing a mixture of diamond and discrete carbide particles, the diamond particles being smaller than the carbide particles and present in the mixture in an amount of more than 50 percent by volume, and subjecting the mixture to diamond synthesis conditions in the presence of a binder metal such as cobalt, nickel or iron. The abrasive product thus produced has a substantial amount of direct diamond-to-diamond bonding and many of the characteristics of a diamond compact, but improved impact resistance due to the presence of the carbide particles. The abrasive product has particular application in the machining of wood products such as natural wood, chipboard, fibreboard and hardboard.
    • SUMMARY OF THE INVENTION
  • The present invention describes a method of abrading a workpiece in a corrosive environment as per claim 1.
  • The diamond abrasive compact which is used in the invention is one which is a polycrystalline mass of diamond having a second phase, the diamond content of the compact comprising at least 70 percent by volume of the compact. The second phase consists of chromium and nickel with any other components being in trace amounts only. It has been found that such diamond compacts have excellent corrosion resistance, particularly in environments in which there is present binder and/or corrosive cleaning chemicals. In the method of the invention, the cutting point or edge on the compact is advanced into workpiece with an abrading action. Abrading in the context of the specification means cutting, drilling, routing, polishing, or any similar such abrading action. This action may take various forms, known in the art, such as rotation of the cutting edge or point, reciprocating movement of the cutting edge or point or the like. Of course, the abrading action can also be achieved by maintaining the edge or point stationary and moving the workpiece.
  • The invention provides, according to another aspect, the use of a diamond abrasive compact as defined above in a method of abrading a workpiece in a corrosive environment.
    • DESCRIPTION OF EMBODIMENTS
  • The mass ratio of chromium to nickel metal will typically be 10:90 to 25:75. In the second phase, the chromium and nickel will both exist in the form of the metal, in the form of carbides and/or in the form of an intermetallic compound of the chromium and the nickel.
  • The diamond abrasive compact has been found to have excellect corrosion resistance in environments in which there is present binder and/or corrosive cleaning chemicals.
  • The diamond abrasive compact may be bonded to a cemented carbide substrate or to a metal layer base such as molybdenum, tantalum or tungsten.
  • Thus, the invention has been found to have particular application in the abrading of products which contain wood. Examples of wood products are natural wood, either soft or hard wood, laminated and non-laminated chipboard and fibreboard, which contain wood chips or fibre bonded by means of binders, hardboard which is compressed fibre and sawdust and plywood. The wood products may have plastic or other coating applied to them. Some of these wood products may contain resins and organic binders. It has been found that the presence of the corrosive cleaning chemicals and/or binder does not result in any significant undercutting of the cutting edge or point of a diamond abrasive compact as described above, leading to a much lower incidence of chipping. The abrading may take the form of sawing, milling or profile cutting. The tools which are used in such applications are generally multi-tip rotary tools such as circular saws, profile cutters, end mills, milling cutters and routers.
  • An example of a method of producing a diamond abrasive compact containing a nickel/chromium second phase will now be described. A mass of diamond particles (16,0g) was placed in a tantalum cup. A disc (2,6g) of a nickel/chromium alloy was placed on top of the mass of diamonds. Thus, the mass ratio of nickel/chromium was 80:20. The nickel/chromium constituted 14 percent by mass of the contents of the loaded tantalum cup.
  • The loaded cup was placed in the reaction zone of a conventional high temperature/high pressure apparatus and subjected to 1500°C temperature and 5,5GPa (55 kilobars) pressure and these conditions were maintained for a period of 10 minutes. Recovered from the reaction zone was a disc-shaped abrasive body which comprised a polycrystalline mass of diamond particles having a second phase containing chromium and nickel, as metals and in various combined forms, uniformly distributed through the diamond mass.

Claims (7)

  1. A method of abrading a workpiece in a corrosive environment including the steps of providing a diamond abrasive compact having a cutting edge or point, the compact being a polycrystalline mass of diamond having a second phase and the diamond content comprising at least 70 percent by volume of the compact, providing a workpiece, bringing the point or edge of the diamond abrasive compact into contact with the workpiece and advancing the edge or point into the workpiece in an abrading manner, characterised in that said second phase consists of chromium and nickel with any other components being in trace amounts only.
  2. A method according to claim 1 wherein the mass ratio of chromium to nickel is in the range 10:90 to 25:75.
  3. A method according to any one of the preceding claims wherein the workpiece is a product which contains wood.
  4. A method according to claim 3 wherein the wood product is selected from natural wood, laminated and non-laminated chipboard and fibreboard, hardboard and plywood.
  5. A method according to claim 3 or claim 4 wherein the wood product has a plastic or other coating applied to it.
  6. A method according to any one of claims 3 to 5 wherein the wood product contains a resin or organic binder.
  7. A method according to any one of the preceding claims wherein the abrading is selected from cutting, drilling, routing and polishing.
EP98301942A 1997-03-17 1998-03-16 Abrading method Expired - Lifetime EP0865876B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ZA9702281 1997-03-17
ZA972281 1997-03-17

Publications (3)

Publication Number Publication Date
EP0865876A2 EP0865876A2 (en) 1998-09-23
EP0865876A3 EP0865876A3 (en) 2000-03-15
EP0865876B1 true EP0865876B1 (en) 2004-01-21

Family

ID=25586303

Family Applications (1)

Application Number Title Priority Date Filing Date
EP98301942A Expired - Lifetime EP0865876B1 (en) 1997-03-17 1998-03-16 Abrading method

Country Status (7)

Country Link
EP (1) EP0865876B1 (en)
JP (1) JP3886242B2 (en)
AT (1) ATE258098T1 (en)
CA (1) CA2231929C (en)
DE (1) DE69821153T2 (en)
ES (1) ES2212223T3 (en)
ZA (1) ZA982097B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8084690B2 (en) 2006-09-18 2011-12-27 Auto Kabel Managementgesellschaft Mbh Ground strap for motor vehicles
US8505654B2 (en) 2009-10-09 2013-08-13 Element Six Limited Polycrystalline diamond

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ATE65726T1 (en) * 1985-04-09 1991-08-15 De Beers Ind Diamond ABRASIVE PRODUCTS.
ZA935524B (en) * 1992-08-05 1994-02-24 De Beers Ind Diamond Abrasive product

Also Published As

Publication number Publication date
ES2212223T3 (en) 2004-07-16
EP0865876A3 (en) 2000-03-15
DE69821153D1 (en) 2004-02-26
EP0865876A2 (en) 1998-09-23
JPH10277949A (en) 1998-10-20
CA2231929A1 (en) 1998-09-17
ZA982097B (en) 1998-09-16
DE69821153T2 (en) 2004-07-08
ATE258098T1 (en) 2004-02-15
JP3886242B2 (en) 2007-02-28
CA2231929C (en) 2007-10-02

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