US2892248A - Method of manufacturing sintered permanent magnets - Google Patents
Method of manufacturing sintered permanent magnets Download PDFInfo
- Publication number
- US2892248A US2892248A US454853A US45485354A US2892248A US 2892248 A US2892248 A US 2892248A US 454853 A US454853 A US 454853A US 45485354 A US45485354 A US 45485354A US 2892248 A US2892248 A US 2892248A
- Authority
- US
- United States
- Prior art keywords
- bodies
- permanent magnets
- sintered permanent
- manufacturing sintered
- 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
Links
- 238000004519 manufacturing process Methods 0.000 title description 8
- 238000005245 sintering Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 9
- 239000000696 magnetic material Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052788 barium Inorganic materials 0.000 description 3
- 230000001427 coherent effect Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052712 strontium Inorganic materials 0.000 description 3
- DSAJWYNOEDNPEQ-UHFFFAOYSA-N barium atom Chemical compound [Ba] DSAJWYNOEDNPEQ-UHFFFAOYSA-N 0.000 description 2
- 230000006378 damage Effects 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 208000027418 Wounds and injury Diseases 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000005347 demagnetization Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000008034 disappearance Effects 0.000 description 1
- 208000014674 injury Diseases 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/26—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on ferrites
- C04B35/2683—Other ferrites containing alkaline earth metals or lead
-
- 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
- H01F1/08—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 pressed, sintered, or bound together
- H01F1/086—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 pressed, sintered, or bound together sintered
-
- 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
- H01F1/10—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 non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure
- H01F1/11—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 non-metallic substances, e.g. ferrites, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure in the form of particles
-
- 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
- This invention relates to a method of manufacturing sintered permanent magnets. More particularly, this invention relates to the premagnetization of bodies of magnetic materials prior to the sintering process.
- Magnetic bodies which are formed from powdered magnetic materials without the use of mechanical binding agents at temperatures below their Curie point, usually at room ⁇ temperatures, and magnetized and pressed before sintering are generally very fragile. Consequently, such molded bodies are apt to become damaged or deteriorate prior to the subsequent sintering process. These bodies may be damaged as a result of collisions due to mutual attraction of the bodies during transportation to the sintering ovens or they may disintegrate of their own accord if the coherence of the material is exceeded by the internal magnetic repulsion of adjacent particles.
- the principal object of this invention is to reduce the damage and deterioration of molded magnetic bodies before sintering.
- a method of manufacturing sintered permanent magnets in which finely-divided particles of permanent magnetic material in either a dry or suspended state are formed into bodies by a molding operation and anisotropically magnetized by a magnetic field during the molding operation and thereafter at least partially demagnetized and sintered.
- the magnetic material utilized in this invention consists of a body built up mainly of hexagonal crystals having dimensions not exceeding 10,11, and having the composition of MO.6Fe O or MFe O in which M represents one of the metals selected from group consisting of Ba, Sr and Pb, with the possible partial replacement of not more than an atomic fraction of 0.4 of one or more of these metals by calcium.
- the molded magnetic materials described above are preferably demagnetized by subjecting them to a demagnetizing field having a strength at least approximately equal to the field strength of disappearance or the intrinsic coercive force, H of the material.
- a method of manufacturing sintered permanent magnets comprising the steps, compacting finely-divided permanent magnet forming material, while in the presence of a magnetic field, into a plurality of bodies each of which are magnetically anisotropic, at least partially demagnetizing each of said magnetic bodies to prevent undesirable collisions during subsequent operations therewith, placing said bodies in close proximity to one another, and sintering said bodies into highly coherent bodies.
- a method of manufacturing sintered permanent magnets comprising the steps, compacting finely-divided permanent magnet forming material selected from the group consisting of MFe O and MFe O in which M is at least one metal selected from the group consisting of barium, strontium, and lead, while in the presence of a magnetic field, into a plurality of bodies each of which are magnetically anisotropic, at least partially demagnetizing each of said magnetic bodies to prevent undesirable collisions during subsequent operations therewith, placing said bodies in close proximity to one another, and sintering said bodies into highly coherent bodies.
- a method of manufacturing sintered permanent magnets comprising the steps, compacting permanent magnet forming material having a given value of intrinsic coercive force H and selected from the group consisting of MFe O and MFe 0 in which M is at least one metal selected from the group consisting of barium, strontium, and lead, while in the presence of a magnetic field, into a plurality of bodies each of which are magnetically anisotropic, at least partially demagnetizing each of said magnetic bodies in a magnetic field having a strength equal at least to the H value of the material to prevent undesirable collisions during subsequent operations therewith, placing said bodies in close proximity to one another, and sintering said bodies into highly coherent bodies.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Power Engineering (AREA)
- Ceramic Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Hard Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL759231X | 1953-09-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2892248A true US2892248A (en) | 1959-06-30 |
Family
ID=19825369
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US454853A Expired - Lifetime US2892248A (en) | 1953-09-09 | 1954-09-08 | Method of manufacturing sintered permanent magnets |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US2892248A (enrdf_load_stackoverflow) |
| BE (1) | BE531693A (enrdf_load_stackoverflow) |
| CH (1) | CH335357A (enrdf_load_stackoverflow) |
| DE (1) | DE972666C (enrdf_load_stackoverflow) |
| FR (1) | FR1114370A (enrdf_load_stackoverflow) |
| GB (1) | GB759231A (enrdf_load_stackoverflow) |
| NL (1) | NL84031C (enrdf_load_stackoverflow) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3090107A (en) * | 1958-07-24 | 1963-05-21 | Sylvania Electric Prod | Method of making a permanent magnet |
| US3244782A (en) * | 1957-05-17 | 1966-04-05 | Magnetics Inc | Toroidal core pressure forming method |
| US3257586A (en) * | 1960-03-03 | 1966-06-21 | Magnetfabrik Bonn Gewerkschaft | Flexible permanent magnet and composition |
| US4000004A (en) * | 1972-10-23 | 1976-12-28 | Agency Of Industrial Science & Technology | Electrode for alkaline storage battery and method for manufacture thereof |
| FR2483120A1 (enrdf_load_stackoverflow) * | 1980-05-23 | 1981-11-27 | Philips Nv |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1378969A (en) * | 1920-03-22 | 1921-05-24 | Western Electric Co | Method of manufacturing inductance-coils |
| US2576679A (en) * | 1939-08-02 | 1951-11-27 | Electro Chimie Metal | Permanent magnet and method of manufacture thereof |
| US2762778A (en) * | 1951-12-21 | 1956-09-11 | Hartford Nat Bank & Trust Co | Method of making magneticallyanisotropic permanent magnets |
-
0
- BE BE531693D patent/BE531693A/xx unknown
- NL NL84031D patent/NL84031C/xx active
-
1954
- 1954-09-05 DE DEN9435A patent/DE972666C/de not_active Expired
- 1954-09-06 GB GB25807/54A patent/GB759231A/en not_active Expired
- 1954-09-07 CH CH335357D patent/CH335357A/de unknown
- 1954-09-07 FR FR1114370D patent/FR1114370A/fr not_active Expired
- 1954-09-08 US US454853A patent/US2892248A/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1378969A (en) * | 1920-03-22 | 1921-05-24 | Western Electric Co | Method of manufacturing inductance-coils |
| US2576679A (en) * | 1939-08-02 | 1951-11-27 | Electro Chimie Metal | Permanent magnet and method of manufacture thereof |
| US2762778A (en) * | 1951-12-21 | 1956-09-11 | Hartford Nat Bank & Trust Co | Method of making magneticallyanisotropic permanent magnets |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3244782A (en) * | 1957-05-17 | 1966-04-05 | Magnetics Inc | Toroidal core pressure forming method |
| US3090107A (en) * | 1958-07-24 | 1963-05-21 | Sylvania Electric Prod | Method of making a permanent magnet |
| US3257586A (en) * | 1960-03-03 | 1966-06-21 | Magnetfabrik Bonn Gewerkschaft | Flexible permanent magnet and composition |
| US4000004A (en) * | 1972-10-23 | 1976-12-28 | Agency Of Industrial Science & Technology | Electrode for alkaline storage battery and method for manufacture thereof |
| FR2483120A1 (enrdf_load_stackoverflow) * | 1980-05-23 | 1981-11-27 | Philips Nv |
Also Published As
| Publication number | Publication date |
|---|---|
| FR1114370A (fr) | 1956-04-11 |
| BE531693A (enrdf_load_stackoverflow) | |
| DE972666C (de) | 1959-09-03 |
| NL84031C (enrdf_load_stackoverflow) | |
| GB759231A (en) | 1956-10-17 |
| CH335357A (de) | 1958-12-31 |
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