EP0354775A2 - Diamond tool - Google Patents

Diamond tool Download PDF

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Publication number
EP0354775A2
EP0354775A2 EP89308081A EP89308081A EP0354775A2 EP 0354775 A2 EP0354775 A2 EP 0354775A2 EP 89308081 A EP89308081 A EP 89308081A EP 89308081 A EP89308081 A EP 89308081A EP 0354775 A2 EP0354775 A2 EP 0354775A2
Authority
EP
European Patent Office
Prior art keywords
diamond
working surface
diamond particles
particles
paste
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.)
Granted
Application number
EP89308081A
Other languages
German (de)
French (fr)
Other versions
EP0354775B1 (en
EP0354775A3 (en
Inventor
Robert Charles Burns
Gabriel Shraga Tolkowsky
Gerrit Jan Lucas Cronselaar
Cornelius Phaal
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.)
De Beers Industrial Diamond Division 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 EP0354775A2 publication Critical patent/EP0354775A2/en
Publication of EP0354775A3 publication Critical patent/EP0354775A3/en
Application granted granted Critical
Publication of EP0354775B1 publication Critical patent/EP0354775B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • B24B37/00—Lapping machines or devices; Accessories
    • B24B37/04—Lapping machines or devices; Accessories designed for working plane surfaces
    • 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
    • B24B9/00—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor
    • B24B9/02—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground
    • B24B9/06—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain
    • B24B9/16—Machines or devices designed for grinding edges or bevels on work or for removing burrs; Accessories therefor characterised by a special design with respect to properties of materials specific to articles to be ground of non-metallic inorganic material, e.g. stone, ceramics, porcelain of diamonds; of jewels or the like; Diamond grinders' dops; Dop holders or tongs
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D7/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting otherwise than only by their periphery, e.g. by the front face; Bushings or mountings therefor
    • B24D7/02—Wheels in one piece

Definitions

  • This invention relates to diamond tools, particularly diamond scaifes.
  • a diamond scaife is a tool which comprises a cast iron plate, one surface of which has a paste containing a plurality of small diamond particles uniformly spread across it. The paste is rubbed on to the surface and then worked in with a piece of low quality diamond.
  • a diamond scaife is a tool used for polishing diamond.
  • a diamond tool comprises an iron-based working surface having a bonding paste of an organic binder uniformly spread across it, the paste containing a plurality of particles of single crystal and polycrystalline diamond which are partially embedded in the iron-based working surface.
  • a method of making a diamond tool as described above which includes the steps of providing an iron-based working surface, depositing a layer of a bonding paste of an organic binder on the surface, the bonding paste containing a plurality of single crystal and polycrystalline diamond particles, and causing the diamond particles to become partially embedded in the working surface.
  • the abrasive elements for the diamond tool will be constituted by a mixture of single crystal and polycrystalline diamond.
  • the paste will constitute a thin film across the iron-based working surface and is believed, in use, to perform some lubricating function.
  • the paste will contain the diamond particles which will also be partially embedded in the iron-based working surface. It has been found that use of this tool results in polishing being achieved without the metal surface coming into contact with the diamond or other material being polished.
  • the diamond tool is preferably a diamond scaife.
  • the working surface may be made of any suitable iron-based material, but is preferably cast iron.
  • the paste will have a coherency sufficient to allow it to remain on the working surface without flowing off it. It will act, at least in part, to locate the diamond particles on the working surface and also as a lubricant.
  • the paste is constituted by an organic binder which may be any known in the art. Examples of suitable binders include cellulose ethers and esters, phenolic resins, dextrin and other similar materials. One preferred organic binder is methyl cellulose.
  • the diamond particles will be fine, i.e. they will generally have a particle size of 40 microns or less. When the diamond tool is to be used for a relatively rough polishing operation, the diamond particles will typically have a size of 10 to 40 microns. For smoothing operations, finer diamond particles of the order of 2 to 10 microns will be used.
  • the diamond particles will be made up of a combination of single crystal diamond and polycrystalline diamond.
  • the polycrystalline diamond particles will generally be produced by crushing a diamond compact.
  • the diamond compact may be one which contains a solvent second phase such as that described in United States Patent No. 3,745,623 and British Patent No. 1,489,130.
  • the polycrystalline diamond may also be produced from a thermally stable diamond compact, that is a diamond compact which can withstand a temperature of 1200°C in a vacuum, inert or non-oxidising atmosphere without any significant graphitisation of the diamond occurring. Examples of such compacts are described in United States Patents Nos. 4,224,380, 4,534,773 and British Patent No. 2,158,086. It is preferred that the polycrystalline diamond is thermally stable, particularly of the type described in British Patent No. 2,158,086.
  • the diamond tool may be made by a method which forms another aspect of the invention. As described above, this method involves providing an iron-based working surface, depositing a layer of a bonding paste of an organic binder on the surface, the bonding paste containing a plurality of single crystal and polycrystalline diamond particles, and causing the diamond particles to become partially embedded in the working surface. Generally, the diamond particles will be caused to become partially embedded in the working surface by rotating that surface and bringing the rotating surface into contact with a diamond surface which is generally a piece of low quality diamond.
  • the bonding paste will preferably be deposited on the working surface in the form of a liquid which contains a solvent and the solvent then allowed to evaporate at least partially, to produce the coherent paste.
  • the solvent will vary according to the nature of the organic binder.
  • the organic binder will be such that the solvent is water.
  • the single crystal diamond particles may be smaller than the polycrystalline diamond particles so that when the particles are caused to become partially embedded in the working surface, the fine single crystal diamond particles tend to locate in spaces between the polycrystalline diamond particles.
  • FIG. 1 of this drawing there is shown a cast-iron disc 10 of a diamond scaife which has an upper working surface 12.
  • This working surface 12 has a uniform layer of bonding paste of an organic binder uniformly spread across it.
  • This bonding paste includes a plurality of diamond particles 14 evenly distributed through it and partially embedded in the working surface 12 of the disc 10.
  • the diamond scaife may be made by depositing a first layer 16 on the working surface 12 of the disc 10 - see Figure 2.
  • This layer 16 will consist of an organic binder containing a plurality of the polycrystalline diamond particles.
  • the layers 16 and 18 are each deposited by providing a liquid mixture of the organic binder, a suitable solvent and the diamond particles, applying that liquid mixture to the relevant surface and allowing the solvent to evaporate leaving a coherent paste layer.
  • the diamonds of the two layers are worked into the surface 12 by rotating the disc 10, for example at a speed of about 2000rpm, and bringing that rotating surface into contact with a diamond surface such as that provided by a low quality diamond.
  • the resulting product is that illustrated by Figure 1.
  • one carat of crushed thermally stable diamond compact containing a silicon second phase (as described in British Patent No. 2,158,086) and of particle size less than 40 microns was rubbed on the cast iron working surface of a scaife with a binder such as dextrin or phenolic resin in a solvent.
  • the solvent was allowed to evaporate leaving a coherent paste.
  • a paste of fine single crystal diamond particles in water containing methyl cellulose was then applied to the coated surface.
  • the water was allowed to evaporate leaving a thin film or layer of coherent methyl cellulose paste containing the diamond particles.
  • the coated working surface was then rotated at a speed of 2000rpm and brought into contact with a low quality diamond.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Cutting Tools, Boring Holders, And Turrets (AREA)

Abstract

A diamond scaife which comprises an iron-based working surface (12) having a bonding paste of an organic binder uniformly spread across it, the paste containing a plurality of particles (14) of single and polycrystalline diamond which are partially embedded in the iron-based working surface (12).

Description

    BACKGROUND OF THE INVENTION
  • This invention relates to diamond tools, particularly diamond scaifes.
  • A diamond scaife is a tool which comprises a cast iron plate, one surface of which has a paste containing a plurality of small diamond particles uniformly spread across it. The paste is rubbed on to the surface and then worked in with a piece of low quality diamond. A diamond scaife is a tool used for polishing diamond.
    • SUMMARY OF THE INVENTION
  • A diamond tool comprises an iron-based working surface having a bonding paste of an organic binder uniformly spread across it, the paste containing a plurality of particles of single crystal and polycrystalline diamond which are partially embedded in the iron-based working surface.
  • According to another aspect of the invention, there is provided a method of making a diamond tool as described above which includes the steps of providing an iron-based working surface, depositing a layer of a bonding paste of an organic binder on the surface, the bonding paste containing a plurality of single crystal and polycrystalline diamond particles, and causing the diamond particles to become partially embedded in the working surface.
    • DESCRIPTION OF THE DRAWING
    • Figure 1 illustrates a perspective view of a diamond tool of the invention; and
    • Figure 2 illustrates a section through the diamond tool during the course of its manufacture.
    DESCRIPTION OF EMBODIMENTS
  • The abrasive elements for the diamond tool will be constituted by a mixture of single crystal and polycrystalline diamond. The paste will constitute a thin film across the iron-based working surface and is believed, in use, to perform some lubricating function. The paste will contain the diamond particles which will also be partially embedded in the iron-based working surface. It has been found that use of this tool results in polishing being achieved without the metal surface coming into contact with the diamond or other material being polished.
  • The diamond tool is preferably a diamond scaife.
  • The working surface may be made of any suitable iron-based material, but is preferably cast iron.
  • The paste will have a coherency sufficient to allow it to remain on the working surface without flowing off it. It will act, at least in part, to locate the diamond particles on the working surface and also as a lubricant. The paste is constituted by an organic binder which may be any known in the art. Examples of suitable binders include cellulose ethers and esters, phenolic resins, dextrin and other similar materials. One preferred organic binder is methyl cellulose.
  • The diamond particles will be fine, i.e. they will generally have a particle size of 40 microns or less. When the diamond tool is to be used for a relatively rough polishing operation, the diamond particles will typically have a size of 10 to 40 microns. For smoothing operations, finer diamond particles of the order of 2 to 10 microns will be used.
  • The diamond particles will be made up of a combination of single crystal diamond and polycrystalline diamond. The polycrystalline diamond particles will generally be produced by crushing a diamond compact. The diamond compact may be one which contains a solvent second phase such as that described in United States Patent No. 3,745,623 and British Patent No. 1,489,130. The polycrystalline diamond may also be produced from a thermally stable diamond compact, that is a diamond compact which can withstand a temperature of 1200°C in a vacuum, inert or non-oxidising atmosphere without any significant graphitisation of the diamond occurring. Examples of such compacts are described in United States Patents Nos. 4,224,380, 4,534,773 and British Patent No. 2,158,086. It is preferred that the polycrystalline diamond is thermally stable, particularly of the type described in British Patent No. 2,158,086.
  • The diamond tool may be made by a method which forms another aspect of the invention. As described above, this method involves providing an iron-based working surface, depositing a layer of a bonding paste of an organic binder on the surface, the bonding paste containing a plurality of single crystal and polycrystalline diamond particles, and causing the diamond particles to become partially embedded in the working surface. Generally, the diamond particles will be caused to become partially embedded in the working surface by rotating that surface and bringing the rotating surface into contact with a diamond surface which is generally a piece of low quality diamond.
  • The bonding paste will preferably be deposited on the working surface in the form of a liquid which contains a solvent and the solvent then allowed to evaporate at least partially, to produce the coherent paste. The solvent will vary according to the nature of the organic binder. Preferably the organic binder will be such that the solvent is water.
  • Generally, two layers of the bonding paste will be deposited on the surface one on top of the other, the layer adjacent the working surface containing the polycrystalline diamond particles and the other layer containing the single crystal diamond particles. In this form of the invention, the single crystal diamond particles may be smaller than the polycrystalline diamond particles so that when the particles are caused to become partially embedded in the working surface, the fine single crystal diamond particles tend to locate in spaces between the polycrystalline diamond particles.
  • An embodiment of the invention will now be described with reference to the accompanying drawings. Referring to Figure 1 of this drawing, there is shown a cast-iron disc 10 of a diamond scaife which has an upper working surface 12. This working surface 12 has a uniform layer of bonding paste of an organic binder uniformly spread across it. This bonding paste includes a plurality of diamond particles 14 evenly distributed through it and partially embedded in the working surface 12 of the disc 10.
  • The diamond scaife may be made by depositing a first layer 16 on the working surface 12 of the disc 10 - see Figure 2. This layer 16 will consist of an organic binder containing a plurality of the polycrystalline diamond particles. On the layer 16 there is deposited a second layer 18 of an organic binder containing a plurality of the single crystal diamond particles. The layers 16 and 18 are each deposited by providing a liquid mixture of the organic binder, a suitable solvent and the diamond particles, applying that liquid mixture to the relevant surface and allowing the solvent to evaporate leaving a coherent paste layer. The diamonds of the two layers are worked into the surface 12 by rotating the disc 10, for example at a speed of about 2000rpm, and bringing that rotating surface into contact with a diamond surface such as that provided by a low quality diamond. The resulting product is that illustrated by Figure 1.
  • In a particular example of the invention, one carat of crushed thermally stable diamond compact containing a silicon second phase (as described in British Patent No. 2,158,086) and of particle size less than 40 microns was rubbed on the cast iron working surface of a scaife with a binder such as dextrin or phenolic resin in a solvent. The solvent was allowed to evaporate leaving a coherent paste. A paste of fine single crystal diamond particles in water containing methyl cellulose was then applied to the coated surface. The water was allowed to evaporate leaving a thin film or layer of coherent methyl cellulose paste containing the diamond particles. The coated working surface was then rotated at a speed of 2000rpm and brought into contact with a low quality diamond. This contact was maintained for 75 minutes to work the polycrystalline diamond particles and the single crystal diamond particles into the working surface. It was found that diamond polishing could be achieved with this scaife without the metal surface coming into contact with the diamond being polished. Further, improved cutting performance was experienced in relation to diamond of 2 carats or larger. This makes the diamond scaife ideally suited for working stressed diamonds.

Claims (10)

1. A diamond tool comprises an iron-based working surface (12) having a bonding paste of an organic binder uniformly spread across it, the paste containing a plurality of particles (14) of single crystal and polycrystalline diamond which are partially embedded in the iron-based working surface (12).
2. A diamond tool according to claim 1 wherein the organic binder is selected from phenolic resins, cellulose ethers and esters and mixtures thereof.
3. A diamond tool according to claim 1 or claim 2 wherein the working surface (12) is a cast iron working surface.
4. A diamond tool according to any one of the preceding claims wherein the polycrystalline diamond particles (14) are thermally stable polycrystalline diamond particles.
5. A diamond tool according to any one of the preceding claims wherein the diamond particles (14) have a size of 40 microns or less.
6. A method of making a diamond tool according to any one of the preceding claims including the steps of providing an iron-based working surface (12), depositing a layer of a bonding paste of an organic binder on the surface, the bonding paste containing a plurality of single crystal and polycrystalline diamond particles (14), and causing the diamond particles to become partially embedded in the working surface (12).
7. A method according to claim 6 wherein the bonding paste is deposited in the form of a liquid containing a solvent and the solvent is allowed to evaporate, at least partially, to produce the paste.
8. A method according to claim 7 wherein the solvent is water.
9. A method according to claim 7 or claim 8 wherein two layers of bonding paste are applied to the surface (12), one on top of the other, the layer (16) adjacent the working surface containing the polycrystalline diamond particles and the other layer (18) containing the single crystal diamond particles.
10. A method according to any one of claims 6 to 9 wherein the diamond particles are caused to become partially embedded in the working surface (12) by rotating that surface (12) and bringing the rotating surface (12) into contact with a diamond surface.
EP89308081A 1988-08-10 1989-08-09 Diamond tool Expired - Lifetime EP0354775B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ZA885879 1988-08-10
ZA885879 1988-08-10

Publications (3)

Publication Number Publication Date
EP0354775A2 true EP0354775A2 (en) 1990-02-14
EP0354775A3 EP0354775A3 (en) 1991-03-27
EP0354775B1 EP0354775B1 (en) 1994-04-27

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ID=25579366

Family Applications (1)

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EP89308081A Expired - Lifetime EP0354775B1 (en) 1988-08-10 1989-08-09 Diamond tool

Country Status (2)

Country Link
EP (1) EP0354775B1 (en)
IL (1) IL91187A0 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2255923A (en) * 1991-05-23 1992-11-25 De Beers Ind Diamond Scaife for diamond cutting or polishing
WO2009059384A1 (en) * 2007-11-05 2009-05-14 Wetenschappelijk En Technisch Onderzoekscentrum Voor Diamant, Inrichting Erkend Bij Toepassing Van De Besluitwet Van 30 Januari 1947 Method and device for mechanically processing diamond
CN102676911A (en) * 2012-05-25 2012-09-19 广州柴油机厂股份有限公司 Wear-resistant cast iron disc and production process thereof

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR993724A (en) * 1948-08-27 1951-11-06 Improvements in the manufacture of abrasive polishers
US2863750A (en) * 1954-10-18 1958-12-09 Sheldon M Booth Method, composition and apparatus for mechanically setting or resetting diamond particles in a working surface
GB1161885A (en) * 1965-12-30 1969-08-20 Paul Michael Troll Improvements in relating to Abrasives.
DE3032027A1 (en) * 1979-08-25 1981-03-26 Kombinat Przemysłu Narzędziowego Vis, Warszawa METHOD FOR PRODUCING GRINDING TOOLS WITH GALVANIC METAL BINDING
SU878551A1 (en) * 1980-03-10 1981-11-07 Львовское Производственное Объединение По Выпуску Искусственных Алмазов И Алмазного Инструмента Metallic binder for manufacturing diamond tool
GB2158086A (en) * 1984-03-30 1985-11-06 De Beers Ind Diamond Abrasive products

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE775418A (en) * 1971-11-17 1972-03-16 Caes Henri METHOD OF HOLDING DIAMOND POWDER ON GRINDING WHEELS.

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR993724A (en) * 1948-08-27 1951-11-06 Improvements in the manufacture of abrasive polishers
US2863750A (en) * 1954-10-18 1958-12-09 Sheldon M Booth Method, composition and apparatus for mechanically setting or resetting diamond particles in a working surface
GB1161885A (en) * 1965-12-30 1969-08-20 Paul Michael Troll Improvements in relating to Abrasives.
DE3032027A1 (en) * 1979-08-25 1981-03-26 Kombinat Przemysłu Narzędziowego Vis, Warszawa METHOD FOR PRODUCING GRINDING TOOLS WITH GALVANIC METAL BINDING
SU878551A1 (en) * 1980-03-10 1981-11-07 Львовское Производственное Объединение По Выпуску Искусственных Алмазов И Алмазного Инструмента Metallic binder for manufacturing diamond tool
GB2158086A (en) * 1984-03-30 1985-11-06 De Beers Ind Diamond Abrasive products

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
SOVIET INVENTIONS ILLUSTRATED Derwent Publications Ltd. abstract number 82-75992E Ý36¨ Bul.41/7.11.81 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2255923A (en) * 1991-05-23 1992-11-25 De Beers Ind Diamond Scaife for diamond cutting or polishing
GB2255923B (en) * 1991-05-23 1994-08-03 De Beers Ind Diamond Scaife for diamond cutting or polishing
WO2009059384A1 (en) * 2007-11-05 2009-05-14 Wetenschappelijk En Technisch Onderzoekscentrum Voor Diamant, Inrichting Erkend Bij Toepassing Van De Besluitwet Van 30 Januari 1947 Method and device for mechanically processing diamond
BE1017837A3 (en) * 2007-11-05 2009-08-04 Wetenschappelijk En Tech Onder METHOD AND DEVICE FOR MECHANICALLY PROCESSING DIAMOND.
RU2483854C2 (en) * 2007-11-05 2013-06-10 Ветенсхаппелейк Эн Технис Ондерзуксентрум Вор Диамант, Инрихтинг Эркенд Бей Тупассинг Ван Де Беслёйтвет Ван 30 Януари 1947 Method of diamond surface machining and device to this end
CN101848791B (en) * 2007-11-05 2013-07-31 依据1947年1月30日法令建立的钻石科学技术研究中心 Method and device for mechanically processing diamond
US8591288B2 (en) 2007-11-05 2013-11-26 Wetenschappelijk En Technisch Onderzoekscentrum Voor Diamant, Inrichting Erkend Bij Toepassing Van De Besluitwet Van 30 Januari 1947 Method and device for mechanically processing diamond
CN102676911A (en) * 2012-05-25 2012-09-19 广州柴油机厂股份有限公司 Wear-resistant cast iron disc and production process thereof
CN102676911B (en) * 2012-05-25 2013-11-13 广州柴油机厂股份有限公司 Wear-resistant cast iron disc and production process thereof

Also Published As

Publication number Publication date
IL91187A0 (en) 1990-03-19
EP0354775B1 (en) 1994-04-27
EP0354775A3 (en) 1991-03-27

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