US3663317A - Method of making a permanent-magnetisable body of compressed fine particles of a compound of m and r - Google Patents
Method of making a permanent-magnetisable body of compressed fine particles of a compound of m and r Download PDFInfo
- Publication number
- US3663317A US3663317A US90512A US3663317DA US3663317A US 3663317 A US3663317 A US 3663317A US 90512 A US90512 A US 90512A US 3663317D A US3663317D A US 3663317DA US 3663317 A US3663317 A US 3663317A
- Authority
- US
- United States
- Prior art keywords
- permanent
- compound
- powder
- fine particles
- ageing
- 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
Links
- 238000004519 manufacturing process Methods 0.000 title abstract description 9
- 150000001875 compounds Chemical class 0.000 title description 10
- 239000010419 fine particle Substances 0.000 title description 4
- 239000000843 powder Substances 0.000 abstract description 12
- 238000005266 casting Methods 0.000 abstract description 6
- 230000003679 aging effect Effects 0.000 abstract description 4
- 229910052761 rare earth metal Inorganic materials 0.000 abstract description 4
- 150000002910 rare earth metals Chemical group 0.000 abstract description 4
- 239000011261 inert gas Substances 0.000 abstract description 3
- 239000007788 liquid Substances 0.000 abstract description 3
- 238000000034 method Methods 0.000 description 17
- 230000032683 aging Effects 0.000 description 11
- 230000000694 effects Effects 0.000 description 4
- 230000003647 oxidation Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000006835 compression Effects 0.000 description 3
- 238000007906 compression Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000000956 alloy Substances 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052776 Thorium Inorganic materials 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 229910000938 samarium–cobalt magnet Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/02—Compacting only
- B22F3/04—Compacting only by applying fluid pressure, e.g. by cold isostatic pressing [CIP]
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
-
- 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
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49075—Electromagnet, transformer or inductor including permanent magnet or core
- Y10T29/49076—From comminuted material
Definitions
- the invention relates to a method of manufacturing a permanent-magnetisable body of fine particles of a compound of M and R, the range of existence of which is integral with that of the compound M R having a hexagonal crystal structure, in which M represents Co or a combination of Co with one or more of the elements Fe, Ni and Cu and R represents one or more of the elements of the rare earth metals and/or Th, in which method a casting of the alloy concerned of M and R is ground to a powder of the desired granular size, the powder being pre-densified and orientated simultaneously or subsequently in a magnetic field, after which it is compressed by an isostatic pressure of at least kbar and finally plastically deformed slightly, while said isostatic pressure is maintained.
- the rare earths are to include also the element Y.
- range of existence is to denote herein a range of concentrations within which for a continuous series of compounds the same crystal structure can be obtained for 100 percent.
- the resultant magnetic body described therein may have a relative density of 97 percent at the most, which is to be understood to mean that the density of the body is 97 percent of the theoretical density of the M-R compound concerned.
- Magnetic bodies thus manufactured have, however, the disadvantageous property that the coercive force decreases with time: there occurs a so-called ageing process.
- this ageing is referred to and recognized as a disadvantage to practical use of the magnetic bodies. This ageing increases with increasing temperature. However, even at room temperature ageing occurs to an undesirable extent.
- Said advantageous effect of said step during the grinding process on ageing is the more surprising as, when considering oxidation in air as being the cause of ageing, it cannot be accounted for how any oxidation, which occurs only for a short time i.e. during the grinding process, may be the cause of the ageing effect in a later stage i.e. when the magnetic body has been manufactured.
- Castings of the compound SmCo were ground by means of a coffee mill in a so-called glove box (gas-tight space in which protrude two gloves fastened by the sleeves in holes of the wall and being thus accessible from without) into powder of an average granular size of about 3 pm.
- the glove box was filled with He gas containing less than 5 ppm of oxygen and/or water vapour.
- the resultant powder, still in the glove box, was poured into a lead holder, orientated in a magnetic field and pre-densified by an isostatic pressure of 8 kbar. Then the lead holder with the block resulting from the compression, was
- the resultant permanent-magnetisable body was found to have a relative density of 97 percent.
- the body was then exposed to a temperature of C in air. After 10 minutes the coercive force was found to be 15.900 Oe. After l00, 1,000 and 10,000 minutes the coercive forces were again measured.
- Graph (a) of FIG. 1 illustrates the variation of the coercive force as a function of time. It should be noted that the ageing effect occurs about 2,000 times more rapidly at a temperature of 100 C than at room temperature. Apart from the time associated with a temperature of 100 C the time associated with a temperature of 27 is therefore plotted on the abscissa.
- the graph of FIG. 1 also shows an ageing curve (b) measured on a permanentmagnetisable body having also a density of 97 percent and made from a powder ground by the same method and having the same chemical composition and the same average granular size, however, not being ground under the conditions characteristic of the method according to the invention.
- the graph of FIG. 2 illustrates for a few magnetic bodies the relationship between the coercive force at the time t(H (t)) and the coercive force at the time t 10 minutes (H,( 10)) and the time during which the magnetic bodies were exposed to air at 100 C.
- the magnetic bodies having densities of 98.5 to 99.9 percent were manufactured by the method according to the invention, whereas the bodies having densities of 95.0 and 97.0 percent were manufactured by the method hitherto known.
- An additional advantage of permanent magnets manufactured from bodies having such high densities resides in that the energy product (BH),,,,, as compared with that of permanent magnets formed from magnetic bodies differing only in density therefrom, is higher.
- the invention relates furthermore to permanent-magnetisable bodies manufactured by the method according to the invention and particularly to such bodies having a relative density of more than 99 percent.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Manufacturing & Machinery (AREA)
- Mechanical Engineering (AREA)
- Hard Magnetic Materials (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
- Powder Metallurgy (AREA)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL6919154A NL6919154A (xx) | 1969-12-20 | 1969-12-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3663317A true US3663317A (en) | 1972-05-16 |
Family
ID=19808680
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US90512A Expired - Lifetime US3663317A (en) | 1969-12-20 | 1970-11-18 | Method of making a permanent-magnetisable body of compressed fine particles of a compound of m and r |
Country Status (10)
Country | Link |
---|---|
US (1) | US3663317A (xx) |
AU (1) | AU2352970A (xx) |
BE (1) | BE760570A (xx) |
CH (1) | CH544388A (xx) |
DE (1) | DE2059303A1 (xx) |
ES (1) | ES386582A1 (xx) |
FR (1) | FR2073860A5 (xx) |
GB (1) | GB1309958A (xx) |
NL (1) | NL6919154A (xx) |
SE (1) | SE372995B (xx) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3771221A (en) * | 1971-12-03 | 1973-11-13 | Bbc Brown Boveri & Cie | Method and apparatus for producing fine-particle permanent magnets |
US3873379A (en) * | 1972-07-12 | 1975-03-25 | Hitachi Metals Ltd | Method of producing rare earth-cobalt permanent magnet using special cooling rates |
US3901742A (en) * | 1974-04-11 | 1975-08-26 | Gen Electric | Removal of lubricants and binders from sinterable powder components |
US4063970A (en) * | 1967-02-18 | 1977-12-20 | Magnetfabrik Bonn G.M.B.H. Vormals Gewerkschaft Windhorst | Method of making permanent magnets |
US4075042A (en) * | 1973-11-16 | 1978-02-21 | Raytheon Company | Samarium-cobalt magnet with grain growth inhibited SmCo5 crystals |
US4104787A (en) * | 1977-03-21 | 1978-08-08 | General Motors Corporation | Forming curved wafer thin magnets from rare earth-cobalt alloy powders |
US4152178A (en) * | 1978-01-24 | 1979-05-01 | The United States Of America As Represented By The United States Department Of Energy | Sintered rare earth-iron Laves phase magnetostrictive alloy product and preparation thereof |
WO1992005903A1 (en) * | 1990-10-09 | 1992-04-16 | Iowa State University Research Foundation, Inc. | A melt atomizing nozzle and process |
US5228620A (en) * | 1990-10-09 | 1993-07-20 | Iowa State University Research Foundtion, Inc. | Atomizing nozzle and process |
US5240513A (en) * | 1990-10-09 | 1993-08-31 | Iowa State University Research Foundation, Inc. | Method of making bonded or sintered permanent magnets |
US5242508A (en) * | 1990-10-09 | 1993-09-07 | Iowa State University Research Foundation, Inc. | Method of making permanent magnets |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3463678A (en) * | 1966-08-15 | 1969-08-26 | Gen Electric | Method for improving magnetic properties of cobalt-yttrium or cobalt-rare earth metal compounds |
US3523836A (en) * | 1967-01-21 | 1970-08-11 | Philips Corp | Permanent magnet constituted of fine particles of a compound m5r |
US3540945A (en) * | 1967-06-05 | 1970-11-17 | Us Air Force | Permanent magnets |
-
1969
- 1969-12-20 NL NL6919154A patent/NL6919154A/xx unknown
-
1970
- 1970-11-18 US US90512A patent/US3663317A/en not_active Expired - Lifetime
- 1970-12-02 DE DE19702059303 patent/DE2059303A1/de active Pending
- 1970-12-16 FR FR7045393A patent/FR2073860A5/fr not_active Expired
- 1970-12-17 GB GB5996870A patent/GB1309958A/en not_active Expired
- 1970-12-17 CH CH1873470A patent/CH544388A/de not_active IP Right Cessation
- 1970-12-17 SE SE7017147A patent/SE372995B/xx unknown
- 1970-12-18 BE BE760570A patent/BE760570A/xx unknown
- 1970-12-18 ES ES386582A patent/ES386582A1/es not_active Expired
- 1970-12-18 AU AU23529/70A patent/AU2352970A/en not_active Expired
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3463678A (en) * | 1966-08-15 | 1969-08-26 | Gen Electric | Method for improving magnetic properties of cobalt-yttrium or cobalt-rare earth metal compounds |
US3523836A (en) * | 1967-01-21 | 1970-08-11 | Philips Corp | Permanent magnet constituted of fine particles of a compound m5r |
US3540945A (en) * | 1967-06-05 | 1970-11-17 | Us Air Force | Permanent magnets |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4063970A (en) * | 1967-02-18 | 1977-12-20 | Magnetfabrik Bonn G.M.B.H. Vormals Gewerkschaft Windhorst | Method of making permanent magnets |
US3771221A (en) * | 1971-12-03 | 1973-11-13 | Bbc Brown Boveri & Cie | Method and apparatus for producing fine-particle permanent magnets |
US3873379A (en) * | 1972-07-12 | 1975-03-25 | Hitachi Metals Ltd | Method of producing rare earth-cobalt permanent magnet using special cooling rates |
US4075042A (en) * | 1973-11-16 | 1978-02-21 | Raytheon Company | Samarium-cobalt magnet with grain growth inhibited SmCo5 crystals |
US3901742A (en) * | 1974-04-11 | 1975-08-26 | Gen Electric | Removal of lubricants and binders from sinterable powder components |
US4123297A (en) * | 1977-03-21 | 1978-10-31 | General Motors Corporation | Forming curved thin magnets from rare earth-transition metal powders |
US4104787A (en) * | 1977-03-21 | 1978-08-08 | General Motors Corporation | Forming curved wafer thin magnets from rare earth-cobalt alloy powders |
US4152178A (en) * | 1978-01-24 | 1979-05-01 | The United States Of America As Represented By The United States Department Of Energy | Sintered rare earth-iron Laves phase magnetostrictive alloy product and preparation thereof |
WO1992005903A1 (en) * | 1990-10-09 | 1992-04-16 | Iowa State University Research Foundation, Inc. | A melt atomizing nozzle and process |
US5125574A (en) * | 1990-10-09 | 1992-06-30 | Iowa State University Research Foundation | Atomizing nozzle and process |
US5228620A (en) * | 1990-10-09 | 1993-07-20 | Iowa State University Research Foundtion, Inc. | Atomizing nozzle and process |
US5240513A (en) * | 1990-10-09 | 1993-08-31 | Iowa State University Research Foundation, Inc. | Method of making bonded or sintered permanent magnets |
US5242508A (en) * | 1990-10-09 | 1993-09-07 | Iowa State University Research Foundation, Inc. | Method of making permanent magnets |
US5470401A (en) * | 1990-10-09 | 1995-11-28 | Iowa State University Research Foundation, Inc. | Method of making bonded or sintered permanent magnets |
Also Published As
Publication number | Publication date |
---|---|
NL6919154A (xx) | 1971-06-22 |
BE760570A (fr) | 1971-06-18 |
DE2059303A1 (de) | 1971-06-24 |
ES386582A1 (es) | 1973-03-16 |
SE372995B (xx) | 1975-01-20 |
FR2073860A5 (xx) | 1971-10-01 |
GB1309958A (en) | 1973-03-14 |
AU2352970A (en) | 1972-06-22 |
CH544388A (de) | 1973-11-15 |
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