US3632242A - Apparatus for making diamonds - Google Patents

Apparatus for making diamonds Download PDF

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Publication number
US3632242A
US3632242A US3418A US3632242DA US3632242A US 3632242 A US3632242 A US 3632242A US 3418 A US3418 A US 3418A US 3632242D A US3632242D A US 3632242DA US 3632242 A US3632242 A US 3632242A
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United States
Prior art keywords
horn
plate
shock wave
anvil
magnetic
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
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US3418A
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English (en)
Inventor
John R Rasquin
Marvin F Estes
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National Aeronautics and Space Administration NASA
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National Aeronautics and Space Administration NASA
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B30—PRESSES
    • B30B—PRESSES IN GENERAL
    • B30B1/00—Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen
    • B30B1/42—Presses, using a press ram, characterised by the features of the drive therefor, pressure being transmitted directly, or through simple thrust or tension members only, to the press ram or platen by magnetic means, e.g. electromagnetic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J3/00—Processes of utilising sub-atmospheric or super-atmospheric pressure to effect chemical or physical change of matter; Apparatus therefor
    • B01J3/06—Processes using ultra-high pressure, e.g. for the formation of diamonds; Apparatus therefor, e.g. moulds or dies
    • B01J3/08—Application of shock waves for chemical reactions or for modifying the crystal structure of substances
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2203/00—Processes utilising sub- or super atmospheric pressure
    • B01J2203/06—High pressure synthesis
    • B01J2203/0605—Composition of the material to be processed
    • B01J2203/061—Graphite
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J2203/00—Processes utilising sub- or super atmospheric pressure
    • B01J2203/06—High pressure synthesis
    • B01J2203/065—Composition of the material produced
    • B01J2203/0655—Diamond
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S425/00—Plastic article or earthenware shaping or treating: apparatus
    • Y10S425/026—High pressure

Definitions

  • the apparatus includes an exponential horn tapering from a large end down to a small end.
  • a copper plate is mounted against the large end of the horn and a magnetic hammer abuts the copper plate.
  • the magnetic hammer and copper plate function to create a shock wave in the exponential horn.
  • An anvil having a small pocket formed therein is mounted adjacent to the small end of the exponential horn so that the small end rests in the pocket. The anvil, horn and hammer are all secured together by bolts or other suitable U.S.
  • CAPACITOR Ila 44 BANK r m l 3 A VOLTAGE 2'4 '4 SOURCE MAGNETIC HAMMER Q II 42 l f 24 l I I 23 l I 2s 26 g l ,32 I
  • the invention relates to the art of making industrial type diamonds and in particular, the invention is a simplified technique for making such diamonds with a simple, but effective apparatus.
  • Industrial grade diamonds are a very important item in the American economy as indicated by the fact that industrial diamonds have been classified by the United States Department of Defense as a special strategic material. There are two sources of industrial grade diamonds; those occurring naturally and obtained by mining, and synthetic diamonds.
  • One application of industrial diamonds is in the making of diamond powder used in grinding wheels for sharpening sintered metal carbide cutting tools used in the metalworking industries and other industries wherein mass production techniques are utilized. Diamond powder is suspended in oil, water or grease and used in polishing and lapping operations.
  • a primary object of this invention is to provide a simplified technique and apparatus for the production of industrial grade synthetic diamonds.
  • Synthetic diamonds are produced by the application of tremendous heat and pressure to carbon materials, but the equipment presently used to generate this great heat and pressure is very massive and expensive.
  • the present invention can be made much simpler and smaller because it utilizes a greatly amplified shock wave to produce the necessary pressure. Since the pressure buildup is extremely rapid, enough heat is generated by the shock along with the pressure to result in the production of diamonds from graphite.
  • the apparatus employed includes an exponential horn of solid hardened steel that tapers from a large end to a small end.
  • a magnetic hammer is positioned adjacent the large end of the exponential horn with a copper plate positioned between the horn and magnetic hammer.
  • An anvil having a small pocket substantially equal in size to the small end of the exponential horn is arranged below the small end of the horn so that the small end fits into the pocket. Pure graphite to be converted into diamonds is placed in the pocket of the anvil and then the hammer, copper plate, exponential horn and anvil are all secured together by a suitable supporting frame work.
  • the magnetic hammer is connected to a capacitor bank and voltage source that delivers an electrical discharge in the form of a fast rising current pulse for operating the hammer and generating a mechanical shock wave in the exponential horn that is directed to the graphite in the anvil.
  • the shock wave I generated in the large end of the exponential horn travels through the horn, and due to the shape of the horn, the shock wave is velocity amplified and concentrated so that substantially all of the energy in the shock wave arrives simultaneously in the small end of the horn contacting the graphite.
  • a high-speed pressure front is applied or transferred to the graphite which generates sufficient heat and pressure therein to convert a part of the graphite to diamond grit.
  • FIG. 1 is a partially cross-sectioned elevational view of an apparatus for practicing the invention
  • FIG. 2 is a chart illustrating the shape of the current pulse applied to the magnetic hammer.
  • FIG. 3 is an enlarged view illustrating the arrangement of the small end of the exponential horn and the graphite in the anvil pocket.
  • the apparatus illustrated in FIG. 1 consists of a magnetic hammer 10 connected to a capacitor bank l2 and voltage source 14 through electrical transmission lines 16.
  • the magnetic hammer has a large coil in the lower end thereof (not shown) and a copper plate 18 is mounted in abutting relation to the lower end of the magnetic hammer.
  • the copper plate and the hammer are separated by a sheet of plastic material 20, mylar for example, to prevent any arcing that might occur between the copper plate and the magnetic hammer during the operation of the apparatus.
  • An exponential horn 22 is positioned immediately below the copper plate. Horn 22 has a large end 24 that tapers down to a small end 26 that fits into a pocket 28 formed in an anvil 30.
  • the horn is fabricated from extremely hard steel, preferably a maraging steel having a Rockwell hardness of 50.
  • the shape of the horn must exactly duplicate that shape which is obtained when the above equation is, by appropriate mathematical manipulations, rotated about the x-axis to obtain a body of revolution. This shape is critical and it has been found, as will be discussed hereafter, that even small variations in shape will result in a loss of efficiency in transmitting and concentrating the energy of the shock wave generated in the large end of the horn.
  • pure graphite 32 is positioned in the pocket underneath the small end of the horn.
  • the apparatus is held together by means of two plates, lower plate 34 and upper plate 36, the upper plate having a hole 38 formed in the center thereof for passage of electrical transmission lines from the magnetic hammer.
  • the two plates are secured together by a plurality of elongated rods 40 and 42 which are threaded at each end to accept nuts 44. Any desired number of elongated rods could be used to assemble the apparatus, four being used in the apparatus shown and in the actual model successfully tested.
  • the operation of the device is as follows: assuming that the apparatus has been assembled in the manner shown in FIG. 1 and graphite has been placed in the pocket of the anvil.
  • the capacitor bank is charged from the voltage source and an electrical discharge, a current pulse having characteristics like that illustrated in the chart of FIG. 2, is applied to the coil (not shown) of the magnetic hammer.
  • the useful portion of the pulse or wave is the first 75 microseconds.
  • the coil is positioned so as to be adjacent the copper plate.
  • Magnetic hammers are known devices and one such hammer which is very similar to that used in this apparatus is described in US. Pat. No. 3,360,972 issued on Jan. 2, 1968.
  • the discharge from the capacitor bank flows through the coil in the magnetic hammer generating an intense magnetic field thereabouts.
  • the magnetic field generated by the coil in the magnetic hammer induces powerful eddy currents in copper plate 18 that are opposite in direction to the current in the coil of the magnetic hammer.
  • the eddy currents also generate a strong magnetic field and the magnetic field developed by the eddy currents in the copper plate is such that it reacts against the magnetic field generated by the coil in the magnetic hammer.
  • the magnetic hammer and copper plate tend to be driven apart and would in fact be driven apart if not held together by the supporting frame work discussed above.
  • shock wave As the shock wave travels down the horn it is velocity amplified and concentrated, due to the shape of the horn, so that all of the energy arrives at the small end of the horn substantially simultaneously.
  • the shock wave then leaves the horn and enters into the graphite.
  • the shock wave entering the graphite is in effect a very rapid pressure front which compresses and heats the graphite sufficiently to promote the formation of diamonds from the graphite.
  • sapphire could be made from aluminum oxide (AIO What is claimed is:
  • An apparatus utilizing electrical energy for generating and applying highly concentrated mechanical shock wave to a mass of material comprising:
  • anvil mounted in said framework having a pocket formed therein for receiving the mass of material
  • an exponential horn mounted adjacent said anvil whose shape is determined by the equation y ce', said horn having an enlarged end that tapers to a necked down end that fits into the pocket in the anvil,
  • a plate mounted adjacent the tuned horn in a position such that one surface of the plate abuts the enlarged end of the horn
  • magnetic means mounted in abutting relation to the surface of said plate opposite that abutting said horn for generating opposite and repelling magnetic field forces in said magnetic means and said plate to result in a reaction that is transferred to the exponential horn and generates a shock wave that travels through and is concentrated and velocity amplified by said horn so that substantially all of the energy in the shock wave arrives simultaneously at the necked down end of the horn in contact with the material to be compressed.
  • an electrical discharge device connected to said magnetic hammer by electrical transmission lines.

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  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Carbon And Carbon Compounds (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
US3418A 1970-01-16 1970-01-16 Apparatus for making diamonds Expired - Lifetime US3632242A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US341870A 1970-01-16 1970-01-16

Publications (1)

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US3632242A true US3632242A (en) 1972-01-04

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US3418A Expired - Lifetime US3632242A (en) 1970-01-16 1970-01-16 Apparatus for making diamonds

Country Status (6)

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US (1) US3632242A (de)
JP (1) JPS5442958B1 (de)
CA (1) CA954018A (de)
DE (1) DE2101283C3 (de)
FR (1) FR2076129B1 (de)
GB (1) GB1333297A (de)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4380421A (en) * 1980-11-10 1983-04-19 Institut Cerac S.A. Die for compaction of powder
US4385880A (en) * 1957-06-27 1983-05-31 Lemelson Jerome H Shock wave processing apparatus
US4602422A (en) * 1984-06-18 1986-07-29 Khanh Dinh Flash compression process for making photovoltaic cells

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3107395A (en) * 1959-11-27 1963-10-22 Gen Electric High pressure high temperature apparatus
US3108325A (en) * 1961-01-13 1963-10-29 Gen Dynamics Corp Forming device
US3184353A (en) * 1961-11-13 1965-05-18 Cavitron Ultrasonics Inc Fastening together of members by high frequency vibrations
US3423794A (en) * 1964-06-30 1969-01-28 Wayne D Wilson Ultrasonic method for producing phase transitions in materials at high pressures

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3107395A (en) * 1959-11-27 1963-10-22 Gen Electric High pressure high temperature apparatus
US3108325A (en) * 1961-01-13 1963-10-29 Gen Dynamics Corp Forming device
US3184353A (en) * 1961-11-13 1965-05-18 Cavitron Ultrasonics Inc Fastening together of members by high frequency vibrations
US3423794A (en) * 1964-06-30 1969-01-28 Wayne D Wilson Ultrasonic method for producing phase transitions in materials at high pressures

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4385880A (en) * 1957-06-27 1983-05-31 Lemelson Jerome H Shock wave processing apparatus
US4380421A (en) * 1980-11-10 1983-04-19 Institut Cerac S.A. Die for compaction of powder
US4602422A (en) * 1984-06-18 1986-07-29 Khanh Dinh Flash compression process for making photovoltaic cells

Also Published As

Publication number Publication date
JPS5442958B1 (de) 1979-12-17
DE2101283A1 (de) 1971-07-22
FR2076129B1 (de) 1973-08-10
DE2101283B2 (de) 1980-11-27
CA954018A (en) 1974-09-03
GB1333297A (en) 1973-10-10
FR2076129A1 (de) 1971-10-15
DE2101283C3 (de) 1981-07-09

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