US3132022A - Metal whiskers having an essentially constant diameter of not more than 1000 angstroms - Google Patents

Metal whiskers having an essentially constant diameter of not more than 1000 angstroms Download PDF

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Publication number
US3132022A
US3132022A US120648A US12064861A US3132022A US 3132022 A US3132022 A US 3132022A US 120648 A US120648 A US 120648A US 12064861 A US12064861 A US 12064861A US 3132022 A US3132022 A US 3132022A
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US
United States
Prior art keywords
whiskers
particles
constant diameter
essentially constant
angstroms
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
US120648A
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English (en)
Inventor
Fred E Luborsky
Charles R Morelock
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US120648A priority Critical patent/US3132022A/en
Priority to GB20503/62A priority patent/GB981172A/en
Priority to DE19621464614 priority patent/DE1464614B1/de
Priority to BE618632A priority patent/BE618632A/fr
Priority to DK273962AA priority patent/DK116143B/da
Priority to CH763162A priority patent/CH409165A/de
Application granted granted Critical
Publication of US3132022A publication Critical patent/US3132022A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/06—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys in the form of particles, e.g. powder
    • 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
    • Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
    • Y10S264/19—Inorganic fiber
    • 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
    • Y10S75/00—Specialized metallurgical processes, compositions for use therein, consolidated metal powder compositions, and loose metal particulate mixtures
    • Y10S75/952—Producing fibers, filaments, or whiskers
    • 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
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12431—Foil or filament smaller than 6 mils

Definitions

  • This invention relates to magnets and more particularly to permanent magnets constructed of nearly perfect single crystal whiskers.
  • Another object of this invention is to provide an improved magnet composed of a plurality of ferromagnetic whiskers.
  • FIG. 1 is a graph showing the intrinsic coercive force of various types of small ferromagnetic particles as a function of the diameters of the particles.
  • FIG. 2 is a greatly enlarged view showing the ferromagnetic whiskers of this invention.
  • the elongated ferromagnetic whiskers of this invention may be composed of iron, nickel, cobalt and alloys of these three metals.
  • Probably the most important single characteristic which the whiskers must have to obtain higher coercive forces than heretofore is an essentially constant diameter throughout the entire length of each whisker.
  • the whiskers are elongated, smooth and of substantially constant diameter throughout their entire lengths. Magnets can be produced from the whiskers by assembling a plurality of them together into one integral magnet body by conventional techniques. I
  • the intrinsic coercive force of the whiskers of this invention is compared to the intrinsic coercive forces of the best small particles currently available.
  • Curve illustrates the intrinsic coercive force, in oersteds, of generally spherically-shaped iron particles produced by electrodeposition into mercury.
  • Curve 11 indicates similar properties for elongated magnetic particles also produced by deposition into mercury.
  • a comparison of the values obtained from the two types of particles clearly indicates that the elongated configuration is much more effective in delivering high coercive forces than is the generally spherical geometry.
  • the coercive forces shown by curve 11 for the mercury-deposited, elongated particles were obtained from specimens having the particles aligned with the long axis parallel to the direction of magnetic measurement, although substantially the same coercive forces are obtained from randomly distributed particles.
  • Curve 12 of the drawings indicates the intrinsic coercive forces of iron whiskers produced according to the present invention.
  • the valves indicated by curve 12 were ob tained from specimens composed of elongated iron 3,132,022 Patented M-ay'5, 1964 ice whiskers whose long axes were randomly distributed with "respectto the direction of magnetic measurement. Additional measurements were made on specimens composed of elongated whiskers whose long axes were aligned generally parallel to the directionof magnetic measurement and it-was found that the coercive forces were substantially the same as the non-aligned Whiskers when the whisker diameters were on the order of about 500 A.
  • the coercive force of an aligned whisker specimen was about 37.5 percent less than that of the non-aligned specimen.
  • Theory indicates that the coercive force of aligned whiskers should become larger than the coercive force of randomly distributed whiskers when the diameter becomes'less than a critical diameter.
  • the theoretical critical diameter is felt to be about 250 A., but test data indicates that the actual critical diameter is somewhat larger, for example between 400 and 500 A.
  • whisker having a diameter of about 250 A. has an intrinsic coercive force of about 3000 oerstedsa-t room temperature, this value being appreciably higher than has previously been obtainable in other small particles.
  • the general shape of the whiskers is indicated. It will be noted that they are elongated, and substantially uniform in diameter throughout the entire length thereof. It is the small diameter and the uniformity of this diameter which makes it possible for the present whiskers to attain their high magnetic properties.
  • the whiskers of this invention may be produced by placing a source metal body and a substrate body in a closed chamber which is continuously evacuated. The chamber is then heated by any suitable means to a temperature such that the source metal body begins to evaporate. The vapor then resulting will be deposited upon the substrate body, which is maintained at a temperature sufficiently below that of the source metal body to provide for deposition and growth of whiskers from its surface.
  • a complete description of the method for producing whiskers can be found in the copending application of Charles R. Morelock Serial No. 120,560, now abandoned, filed concurrently herewith and assigned to the same assignee as the present invention.
  • Magnets can be produced using the present whiskers by agglomerating a plurality of the whiskers in a suitable matrix material.
  • a metal such as lead or a plastic matrix, may be used to combine the whiskers. Measurements were made of a magnet produced by combining a plurality of whiskers on an insulating plastic film and it was found to have coercive forces superior to mag nets previously produced. from existing small ferromagnetic particles.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)
  • Paints Or Removers (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
US120648A 1961-06-29 1961-06-29 Metal whiskers having an essentially constant diameter of not more than 1000 angstroms Expired - Lifetime US3132022A (en)

Priority Applications (6)

Application Number Priority Date Filing Date Title
US120648A US3132022A (en) 1961-06-29 1961-06-29 Metal whiskers having an essentially constant diameter of not more than 1000 angstroms
GB20503/62A GB981172A (en) 1961-06-29 1962-05-28 Magnets
DE19621464614 DE1464614B1 (de) 1961-06-29 1962-05-30 Verfahren zur Herstellung eines Dauermagneten
BE618632A BE618632A (fr) 1961-06-29 1962-06-06 Aimant permanent
DK273962AA DK116143B (da) 1961-06-29 1962-06-19 Permanent magnet opbygget af et antal langstrakte ferromagnetiske partikler.
CH763162A CH409165A (de) 1961-06-29 1962-06-25 Permanentmagnet

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US120648A US3132022A (en) 1961-06-29 1961-06-29 Metal whiskers having an essentially constant diameter of not more than 1000 angstroms

Publications (1)

Publication Number Publication Date
US3132022A true US3132022A (en) 1964-05-05

Family

ID=22391665

Family Applications (1)

Application Number Title Priority Date Filing Date
US120648A Expired - Lifetime US3132022A (en) 1961-06-29 1961-06-29 Metal whiskers having an essentially constant diameter of not more than 1000 angstroms

Country Status (6)

Country Link
US (1) US3132022A (fr)
BE (1) BE618632A (fr)
CH (1) CH409165A (fr)
DE (1) DE1464614B1 (fr)
DK (1) DK116143B (fr)
GB (1) GB981172A (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3278342A (en) * 1963-10-14 1966-10-11 Westinghouse Electric Corp Method of growing crystalline members completely within the solution melt
US3434892A (en) * 1964-11-05 1969-03-25 Magnetfab Bonn Gmbh Directionally solidified permanent magnet alloys with aligned ferro-magnetic whiskers
US3542541A (en) * 1966-03-15 1970-11-24 United Aircraft Corp Whisker reinforced alloys and method of making the same
US3607451A (en) * 1969-10-08 1971-09-21 Us Army Process for forming iron whiskers of uniform high quality
US4113521A (en) * 1974-04-15 1978-09-12 International Business Machines Corporation Process for producing magnetic particles by vacuum evaporation of iron with collection on a magnetized surface
US4784703A (en) * 1983-08-26 1988-11-15 Grumman Aerospace Corporation Directional solidification and densification of permanent magnets having single domain size MnBi particles
US20040028936A1 (en) * 2001-03-08 2004-02-12 Masaki Kogiso Metalic nanowire and process for producing the same

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5376957A (en) * 1976-12-20 1978-07-07 Hitachi Maxell Magnetic metal iron powder and said manufacturing process
AU598370B2 (en) * 1987-06-12 1990-06-21 Minnesota Mining And Manufacturing Company Process for metal fibers

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2974104A (en) * 1955-04-08 1961-03-07 Gen Electric High-energy magnetic material

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2879154A (en) * 1956-10-02 1959-03-24 Franklin Inst Of The State Of Acicular metal particles and method of making the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2974104A (en) * 1955-04-08 1961-03-07 Gen Electric High-energy magnetic material

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3278342A (en) * 1963-10-14 1966-10-11 Westinghouse Electric Corp Method of growing crystalline members completely within the solution melt
US3434892A (en) * 1964-11-05 1969-03-25 Magnetfab Bonn Gmbh Directionally solidified permanent magnet alloys with aligned ferro-magnetic whiskers
US3542541A (en) * 1966-03-15 1970-11-24 United Aircraft Corp Whisker reinforced alloys and method of making the same
US3607451A (en) * 1969-10-08 1971-09-21 Us Army Process for forming iron whiskers of uniform high quality
US4113521A (en) * 1974-04-15 1978-09-12 International Business Machines Corporation Process for producing magnetic particles by vacuum evaporation of iron with collection on a magnetized surface
US4784703A (en) * 1983-08-26 1988-11-15 Grumman Aerospace Corporation Directional solidification and densification of permanent magnets having single domain size MnBi particles
US20040028936A1 (en) * 2001-03-08 2004-02-12 Masaki Kogiso Metalic nanowire and process for producing the same
US6858318B2 (en) * 2001-03-08 2005-02-22 Japan Science And Technology Corporation Metalic nanowire and process for producing the same

Also Published As

Publication number Publication date
BE618632A (fr) 1962-10-01
GB981172A (en) 1965-01-20
DE1464614B1 (de) 1970-08-20
CH409165A (de) 1966-03-15
DK116143B (da) 1969-12-15

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