CA1075567A - Method for producing permanent magnets - Google Patents
Method for producing permanent magnetsInfo
- Publication number
- CA1075567A CA1075567A CA257,605A CA257605A CA1075567A CA 1075567 A CA1075567 A CA 1075567A CA 257605 A CA257605 A CA 257605A CA 1075567 A CA1075567 A CA 1075567A
- Authority
- CA
- Canada
- Prior art keywords
- binder
- temperature
- mold
- mixture
- vibration
- 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
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
- H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets
- H01F41/0266—Moulding; Pressing
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Hard Magnetic Materials (AREA)
- Manufacturing Cores, Coils, And Magnets (AREA)
- Powder Metallurgy (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of making permanent magnets from magnetic powders employs the steps of comminuting the magnetic material to a powder and mixing the powder with a suitable binder.
The resultant mixture is placed in a mold where predetermined pressure and vibration are simultaneously applied under the influence of a magnetic field. Metals, thermoplastic or thermosetting materials may be used as binders. When using any of these materials, the binder should have a solidification or setting temperature which appropriately differs from the mold temperature. When a binder composed of a material which softens with increase in temperature above a predetermined temperature is used, the mold is held at a temperature below said predetermine temperature. When a binder composed of a material which hardens with increase in temperature above a predetermined temperature is used, the mold is held above the predetermined hardening temperature. A preferred form of vibratory source is an ultrasonic resonator device.
A method of making permanent magnets from magnetic powders employs the steps of comminuting the magnetic material to a powder and mixing the powder with a suitable binder.
The resultant mixture is placed in a mold where predetermined pressure and vibration are simultaneously applied under the influence of a magnetic field. Metals, thermoplastic or thermosetting materials may be used as binders. When using any of these materials, the binder should have a solidification or setting temperature which appropriately differs from the mold temperature. When a binder composed of a material which softens with increase in temperature above a predetermined temperature is used, the mold is held at a temperature below said predetermine temperature. When a binder composed of a material which hardens with increase in temperature above a predetermined temperature is used, the mold is held above the predetermined hardening temperature. A preferred form of vibratory source is an ultrasonic resonator device.
Description
FIEI.D OF TIIE INVENTION
This invention relates to a method for the manufacture of permanent magnets by comminuting a substance of high magnetic crystal anisotropy to a powder, mixing the powder with a binder, applying a magnetic field to the mixture and treating the mixture by the application of pressure and vibration to produce a molded body.
BACKCROUND OF THE INVENTION
_ . . ., Methods of the above kind for the manufacture of permanent magnets are known, for example, from Swiss Patent Specification 516,217, especially Column 4, paragraphs 2, 3 and 4 They lead to comparatively mechanically stable molded bodies. -secause of the high viscosity of the resln mixture, however, the alignment of the particles in the magnetic field is greatly impeded. The high viscosity results from the high proportion of the mixture consis~in~ of a very finely pu]verized magnetizable substance.
Subsequent impregnation of an already manufactured compressed molded body with particular solvents or epoxide resins -such as is described in Swiss Patent Specification 500,573, has also not proved very successful in practice, since, on the one hand, it cannot be carried out for small bodies (e.g., lx 1 x 1 mm) and, on the other hand, it is not economical for larger parts, especially for mass production.
This invention relates to a method for the manufacture of permanent magnets by comminuting a substance of high magnetic crystal anisotropy to a powder, mixing the powder with a binder, applying a magnetic field to the mixture and treating the mixture by the application of pressure and vibration to produce a molded body.
BACKCROUND OF THE INVENTION
_ . . ., Methods of the above kind for the manufacture of permanent magnets are known, for example, from Swiss Patent Specification 516,217, especially Column 4, paragraphs 2, 3 and 4 They lead to comparatively mechanically stable molded bodies. -secause of the high viscosity of the resln mixture, however, the alignment of the particles in the magnetic field is greatly impeded. The high viscosity results from the high proportion of the mixture consis~in~ of a very finely pu]verized magnetizable substance.
Subsequent impregnation of an already manufactured compressed molded body with particular solvents or epoxide resins -such as is described in Swiss Patent Specification 500,573, has also not proved very successful in practice, since, on the one hand, it cannot be carried out for small bodies (e.g., lx 1 x 1 mm) and, on the other hand, it is not economical for larger parts, especially for mass production.
-2-. ___ . .., ...~_ ~ .
10755~7 SUMMARY OF THE PRESENT INVENTION
~ It is a principal object of the invention to provide a method for the manufacture of permanent magnets which does not suffer from the disadvantages of known methods of manufacture and is superior to these in technical and/or economic respects.
According to the present invention there is provided a method for the manufacture of permanent magnets comprising the steps of comminuting a substance of high magnetic crystal anistropy to form a powder mixture, mixing the powder mixture with a binder, and applying a magnetic field to the resultant mixture with the binder and processing the resultant mixture in a mold to produce a molded body while using pressure and vibratior , the pressure and vibration being simultaneously applied during the molding process. The binder is either composed of a material which softens with increase in temperature above a predetermined temperature or of a material which hardens with increase in temperature above a predetermined temperature. The mold is held at a temperature below the predetermined temperature for softening when a binder which softens with increasing temperature is used. The mold is held at a temperature above the predetermin~ d temperature for hardening when a binder which hardens with temperature is used.
For a better understanding of the present invention, reference is made to the accompanying drawing and detailed description of various embodiments of the invention, while the scope of the invention will be pointed out in the amended claims.
10755~7 SUMMARY OF THE PRESENT INVENTION
~ It is a principal object of the invention to provide a method for the manufacture of permanent magnets which does not suffer from the disadvantages of known methods of manufacture and is superior to these in technical and/or economic respects.
According to the present invention there is provided a method for the manufacture of permanent magnets comprising the steps of comminuting a substance of high magnetic crystal anistropy to form a powder mixture, mixing the powder mixture with a binder, and applying a magnetic field to the resultant mixture with the binder and processing the resultant mixture in a mold to produce a molded body while using pressure and vibratior , the pressure and vibration being simultaneously applied during the molding process. The binder is either composed of a material which softens with increase in temperature above a predetermined temperature or of a material which hardens with increase in temperature above a predetermined temperature. The mold is held at a temperature below the predetermined temperature for softening when a binder which softens with increasing temperature is used. The mold is held at a temperature above the predetermin~ d temperature for hardening when a binder which hardens with temperature is used.
For a better understanding of the present invention, reference is made to the accompanying drawing and detailed description of various embodiments of the invention, while the scope of the invention will be pointed out in the amended claims.
-3--.. . ~_ ,: ~
. .
" ' ' : ' ~ ' ., ~
` ~ 1075567 BRIEF DESC~IPTION OF THE DRAWING
. ._ _ .
The drawing represents, in partially schematic representation, apparatus for performing the method of the present invention.
DETAIL_D DESCRIPTION OF THE INVENTION
The apparatus shown in the drawing comprises essentially a press consisting of an upper press ram (upper die) 1, a press cylinder (mold) 2 and a lower press ram (ejector) 3, the rams 1 and 3 being operatively coupled with air-pressure cylinders 4 and 5, respectively. The upper press ram 1 is constructed as an ultrasonic resonator, which is fed by an ultrasonic generator 6 The press cylinder 2 is surrounded by a magnetizing coil 7. With the exception of the magnetizing coil, the construction of the apparatus corresponds more or less to a known plastics ultrasonic welding machine.
The powder mixture consisting of magnetic powder and binding medium is filled loosely into the mold 2. Suitable binding media are plastics powders, such as,for example, PPS (polyphenyl sulfide, melting point 290C, density 1.34 g/cm3), PA-11 (poIyamide 11, melting point 185C, density 1.04 g/cm3), PE (polyethylene, melting point about 110 - 110C, density 0.91 ).94 g/mm3) or polyester thermoplastics, such as that _4_ . .
.
.. _ .
~075567 marketed under the Trade Mark "Ultradur" by BASF (melting point 225 - 260C, density 1.29 - 1.37 g/cm3). All the plastic powders named above are commercially available and can be supplied in different gra-in sizes. Additionally, low melting-point metals or metal alloys, with melting points not exceeding 300C, for example, pure tin, Wood's metal and the like can be employed as binding media. Practically all magnetic materials known in the present state of the art, such as are described, for example in Swiss Patent Specification No. 616,217, with grain sizes between 5 and 50 microns, are suitable for use as the magnetic powder.
After the powder mixture has been filled into the mold, a pre-compression of the powder mixture is effected with the help of the upper press ram 1, without the use of ultrasonic energy but with the simultaneous application of a magnetic field of not less than 5,000 Oersteds. After the withdrawal of the upper press ram 1, the precompressed tablet is brought flush with the upper margin of the mold 2 by actuation of the lower press ram 3. The upper press ram 1 is again applied and the tablet is compressed for about 1 second with the simultaneous application of pressure (200 kp/cm2), ultrasonic ener~y (amplitude of oscillation not less than 30 microns) and aligning magnetic field. ~fter a cooling time of some 2 seconds, the completed magnetic body may be removed from the mold by the renewed actuation of the lower press ram 3.
_ _ _ _ :
, ~ ' . ` .
It has been found that powder mixtures using polyethylene as the binding medium lead to the best results. It flows-readily into the mold, any surplus being squeezed out laterally adjacent the upper press ram. The completed magnets may readily be removed from the mold. Since polyethylene is a comparatively soft plastics material, the completed magnets may likewise be readily worked. However, powder mixtures using tin as the -binding medium also lead to high quality magnet bodies, even though the completed, pressed magnet bodies tend to stick to the rams or mold, which may, however, be easily avoided by appropriate choi~e of the materials from which the press tools are made.
Relatively homogeneous magnetic bodies may be made up to magnet heights of some 2 mm for metallic binding media and some 3 to ~ mm for plastics materials. For greater heights, difficulties arise, since it is difficult to produce a homogeneou distribution of energy in the blank.
The method according to the invention, as has been described above, is particularly suitable for the manufacture of cobalt-rare earth magnets, but may, however, also be employed for Al-Ni-Co magnets. The powder mixture, consisting of the comminuted magnetic substance and solid or liquid binding medium, is introduced into the mold cavity as a powder, a mass or a shape tablet and is treated in the magnetic field with the assistance of pres re and vibration, preferably ultrasonic vibration.
,'' ' .
I `
---- ~ ~
` -For thermoplastic binding media, the mold temperature should bebelow the solidification (freezing) point of the thermoplastic material. The mold is kept below the "solidification" point in order to prevent melting of the resin particles before application of pressure and vibration. Because of the oscillator Y
absorption of the thermoplastic in the ultrasonic range (20 kHz - 40 kHz), the thermoplastic material melts. Similar conditions apply for metals when used as the binding medium.
Here, the metal is brought to its melting point by the ultrasonic energy.
On the other hand, for hardenable synthetic materials (thermosetting materials), the mold temperature should be higher than the hardening (setting or curing) temperature of the thermosetting material. Through application of the ultrasonic oscillation, the synthetic resin is heated and the hardening process is thus initiated. In this case, the energy supplied by ultrasonic vibration must be stopped immediately after the curing process is completed. Otherwise, the already compacted and solidified molded body would be destroyed again mechanically.
In addition to the introduction of heat and the change in condition of the binding medium associated therewith, the oscillatory treatment has the effect of making comparatively high-viscosity mixtures more fluid, so that the alignment of the particles in the magnetic field is considerably facilitated.
At the same time, the packing density of the màgnetic material is increased.
10755~;7 The described method of manufacture of magnetic bodies is particularly suitable for mass production because of the short handling times, and provides high-quality magnetic bodies that are easy to machine and to manufacture. The method of manufacture is particularly simple if the binding medium and the magnetic powder are not mixed from separate fractions before filling into the mold, but magnetic powder with an existinc coating of a binding medium is employed. Magnetic powder of this kind is known from the aforementioned Swiss Patent Specification 516,217, especially, Example 10 (acrylic binding medium). However, magnetic powder provided with a coating of tin or some other melting point metal may also be employed.
.` ~
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes in form and detail may be made therein without departing from the true spirit and scope of the present invention.
., . .
`:
, .
. .
" ' ' : ' ~ ' ., ~
` ~ 1075567 BRIEF DESC~IPTION OF THE DRAWING
. ._ _ .
The drawing represents, in partially schematic representation, apparatus for performing the method of the present invention.
DETAIL_D DESCRIPTION OF THE INVENTION
The apparatus shown in the drawing comprises essentially a press consisting of an upper press ram (upper die) 1, a press cylinder (mold) 2 and a lower press ram (ejector) 3, the rams 1 and 3 being operatively coupled with air-pressure cylinders 4 and 5, respectively. The upper press ram 1 is constructed as an ultrasonic resonator, which is fed by an ultrasonic generator 6 The press cylinder 2 is surrounded by a magnetizing coil 7. With the exception of the magnetizing coil, the construction of the apparatus corresponds more or less to a known plastics ultrasonic welding machine.
The powder mixture consisting of magnetic powder and binding medium is filled loosely into the mold 2. Suitable binding media are plastics powders, such as,for example, PPS (polyphenyl sulfide, melting point 290C, density 1.34 g/cm3), PA-11 (poIyamide 11, melting point 185C, density 1.04 g/cm3), PE (polyethylene, melting point about 110 - 110C, density 0.91 ).94 g/mm3) or polyester thermoplastics, such as that _4_ . .
.
.. _ .
~075567 marketed under the Trade Mark "Ultradur" by BASF (melting point 225 - 260C, density 1.29 - 1.37 g/cm3). All the plastic powders named above are commercially available and can be supplied in different gra-in sizes. Additionally, low melting-point metals or metal alloys, with melting points not exceeding 300C, for example, pure tin, Wood's metal and the like can be employed as binding media. Practically all magnetic materials known in the present state of the art, such as are described, for example in Swiss Patent Specification No. 616,217, with grain sizes between 5 and 50 microns, are suitable for use as the magnetic powder.
After the powder mixture has been filled into the mold, a pre-compression of the powder mixture is effected with the help of the upper press ram 1, without the use of ultrasonic energy but with the simultaneous application of a magnetic field of not less than 5,000 Oersteds. After the withdrawal of the upper press ram 1, the precompressed tablet is brought flush with the upper margin of the mold 2 by actuation of the lower press ram 3. The upper press ram 1 is again applied and the tablet is compressed for about 1 second with the simultaneous application of pressure (200 kp/cm2), ultrasonic ener~y (amplitude of oscillation not less than 30 microns) and aligning magnetic field. ~fter a cooling time of some 2 seconds, the completed magnetic body may be removed from the mold by the renewed actuation of the lower press ram 3.
_ _ _ _ :
, ~ ' . ` .
It has been found that powder mixtures using polyethylene as the binding medium lead to the best results. It flows-readily into the mold, any surplus being squeezed out laterally adjacent the upper press ram. The completed magnets may readily be removed from the mold. Since polyethylene is a comparatively soft plastics material, the completed magnets may likewise be readily worked. However, powder mixtures using tin as the -binding medium also lead to high quality magnet bodies, even though the completed, pressed magnet bodies tend to stick to the rams or mold, which may, however, be easily avoided by appropriate choi~e of the materials from which the press tools are made.
Relatively homogeneous magnetic bodies may be made up to magnet heights of some 2 mm for metallic binding media and some 3 to ~ mm for plastics materials. For greater heights, difficulties arise, since it is difficult to produce a homogeneou distribution of energy in the blank.
The method according to the invention, as has been described above, is particularly suitable for the manufacture of cobalt-rare earth magnets, but may, however, also be employed for Al-Ni-Co magnets. The powder mixture, consisting of the comminuted magnetic substance and solid or liquid binding medium, is introduced into the mold cavity as a powder, a mass or a shape tablet and is treated in the magnetic field with the assistance of pres re and vibration, preferably ultrasonic vibration.
,'' ' .
I `
---- ~ ~
` -For thermoplastic binding media, the mold temperature should bebelow the solidification (freezing) point of the thermoplastic material. The mold is kept below the "solidification" point in order to prevent melting of the resin particles before application of pressure and vibration. Because of the oscillator Y
absorption of the thermoplastic in the ultrasonic range (20 kHz - 40 kHz), the thermoplastic material melts. Similar conditions apply for metals when used as the binding medium.
Here, the metal is brought to its melting point by the ultrasonic energy.
On the other hand, for hardenable synthetic materials (thermosetting materials), the mold temperature should be higher than the hardening (setting or curing) temperature of the thermosetting material. Through application of the ultrasonic oscillation, the synthetic resin is heated and the hardening process is thus initiated. In this case, the energy supplied by ultrasonic vibration must be stopped immediately after the curing process is completed. Otherwise, the already compacted and solidified molded body would be destroyed again mechanically.
In addition to the introduction of heat and the change in condition of the binding medium associated therewith, the oscillatory treatment has the effect of making comparatively high-viscosity mixtures more fluid, so that the alignment of the particles in the magnetic field is considerably facilitated.
At the same time, the packing density of the màgnetic material is increased.
10755~;7 The described method of manufacture of magnetic bodies is particularly suitable for mass production because of the short handling times, and provides high-quality magnetic bodies that are easy to machine and to manufacture. The method of manufacture is particularly simple if the binding medium and the magnetic powder are not mixed from separate fractions before filling into the mold, but magnetic powder with an existinc coating of a binding medium is employed. Magnetic powder of this kind is known from the aforementioned Swiss Patent Specification 516,217, especially, Example 10 (acrylic binding medium). However, magnetic powder provided with a coating of tin or some other melting point metal may also be employed.
.` ~
While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes in form and detail may be made therein without departing from the true spirit and scope of the present invention.
., . .
`:
, .
Claims (11)
1. A method for the manufacture of permanent magnets comprising the steps of:
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder, said binder being composed of a material which softens with increase in temperature above a predetermined temperature or of a material which hardens with increase in temperature above a predetermined temperature; and applying a magnetic field to the resultant mixture with said binder and processing the resultant mixture in a mold to produce a molded body while using pressure and vibration, said pressure and vibration being simultaneously applied during the molding process, said mold being held at a temperature below the predetermined temperature for softening when a binder which softens with increase in temperature is used and said mold being held at a temperature above the predetermined temperature of hardening when a binder which hardens with increase in temperature is used.
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder, said binder being composed of a material which softens with increase in temperature above a predetermined temperature or of a material which hardens with increase in temperature above a predetermined temperature; and applying a magnetic field to the resultant mixture with said binder and processing the resultant mixture in a mold to produce a molded body while using pressure and vibration, said pressure and vibration being simultaneously applied during the molding process, said mold being held at a temperature below the predetermined temperature for softening when a binder which softens with increase in temperature is used and said mold being held at a temperature above the predetermined temperature of hardening when a binder which hardens with increase in temperature is used.
2. A method in accordance with Claim 1 wherein the binder is a synthetic resin.
3. A method in accordance with Claim 1 wherein the binder is a metal having a melting point of lower than 300°C.
4. A method in accordance with Claim 1 wherein the binder is applied to the magnetic powder in the form of a coating upon the powder particles.
5. A method in accordance with Claim 1 wherein a press ram in the form of an ultrasonic resonator is used to apply pressure to the mixture and to subject the mixture to vibration.
6. A method in accordance with Claim 1 wherein the mixture is treated with compression pressure which is larger than 200 kp/cm2 and with oscillation amplitudes larger than 30 mm.
7. A method in accordance with Claim 2 wherein said synthetic resin is a thermoplastic or duroplastic resin.
8. A method for the manufacture of permanent magnets comprising the steps of:
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder to form a resultant mixture, said binder being composed of a material which softens with increase in temperature above a predetermined temperature;
disposing said resultant mixture with binder in a mold;
and subjecting said mold with resultant mixture to pressure and vibration under the influence of a magnetic field applied to said resultant mixture to produce a molded body, said pressure and vibration being simultaneously applied during the molding process, the mold being held substantially at a temperature below the predetermined softening temperature of the binder.
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder to form a resultant mixture, said binder being composed of a material which softens with increase in temperature above a predetermined temperature;
disposing said resultant mixture with binder in a mold;
and subjecting said mold with resultant mixture to pressure and vibration under the influence of a magnetic field applied to said resultant mixture to produce a molded body, said pressure and vibration being simultaneously applied during the molding process, the mold being held substantially at a temperature below the predetermined softening temperature of the binder.
9. A method in accordance with Claim 8 wherein said mold containing said resultant mixture is first subject to a pre-compression step of compacting under the influence of a magnetic field only and the step of compressing the compacted mixture follows under the influence of the magnetic field and predetermined pressure and vibration.
10. A method for the manufacture of permanent magnets comprising the steps of:
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder to form a resultant mixture, said binder being composed of a material which hardens with increase in temperature above a predetermined temperature;
disposing said resultant mixture with binder in a mold;
and subjecting said mold with resultant mixture to pressure and vibration under the influence of a magnetic field applied to said resultant mixture to produce a molded body, said pressure and vibration being simultaneously applied during the molding process, the mold being held substantially at a temperature above the hardening temperature of the binder.
comminuting a substance of high magnetic crystal anisotropy to form a powder mixture;
mixing the powder mixture with a binder to form a resultant mixture, said binder being composed of a material which hardens with increase in temperature above a predetermined temperature;
disposing said resultant mixture with binder in a mold;
and subjecting said mold with resultant mixture to pressure and vibration under the influence of a magnetic field applied to said resultant mixture to produce a molded body, said pressure and vibration being simultaneously applied during the molding process, the mold being held substantially at a temperature above the hardening temperature of the binder.
11. A method in accordance with Claim 10 wherein said mold containing said resultant mixture is first subject to a pre-compression step of compacting under the influence of a magentic field only and the step of compressing the compacted mixture follows under the influence of the magnetic field and predetermined pressure and vibration.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH966075A CH586954A5 (en) | 1975-07-24 | 1975-07-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1075567A true CA1075567A (en) | 1980-04-15 |
Family
ID=4354314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA257,605A Expired CA1075567A (en) | 1975-07-24 | 1976-07-23 | Method for producing permanent magnets |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS5214898A (en) |
| CA (1) | CA1075567A (en) |
| CH (1) | CH586954A5 (en) |
| DE (1) | DE2535745A1 (en) |
| FR (1) | FR2319185A1 (en) |
| GB (1) | GB1531317A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105623240A (en) * | 2015-12-17 | 2016-06-01 | 上海交通大学 | Anisotropic high-molecular permanent magnetic compound material and preparation method therefor |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS568750Y2 (en) * | 1978-11-07 | 1981-02-25 | ||
| DE3006736A1 (en) * | 1979-02-23 | 1980-09-04 | Inoue Japax Res | METHOD AND DEVICE FOR PRODUCING AN ELASTOMERIC MAGNETIC OBJECT |
| JPS6033285B2 (en) * | 1979-12-20 | 1985-08-02 | 住友ベークライト株式会社 | plastic magnet composition |
| GB2128849A (en) * | 1982-10-14 | 1984-05-02 | Bestobell | Transducer element |
| US4810572A (en) * | 1986-02-17 | 1989-03-07 | Mitsui Toatsu Chemicals, Inc. | Permanent magnet and process for producing the same |
| US6007757A (en) * | 1996-01-22 | 1999-12-28 | Aichi Steel Works, Ltd. | Method of producing an anisotropic bonded magnet |
| DE102008019959A1 (en) * | 2008-04-21 | 2009-10-22 | Blue Object Ohg | Magnetic surface, for the display of paper notices and the like, is of woven wire tensed between upper holder and lower weighted rod |
| DE102016205243A1 (en) * | 2016-03-30 | 2017-10-05 | Thyssenkrupp Ag | Apparatus and method for processing a sample material |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3849213A (en) * | 1966-09-01 | 1974-11-19 | M Baermann | Method of producing a molded anisotropic permanent magnet |
| DE2258780A1 (en) * | 1971-12-14 | 1973-06-28 | Goldschmidt Ag Th | PROCESS FOR PRODUCING PERMANENT MAGNETS BASED ON COBALT-RARE EARTH ALLOYS |
-
1975
- 1975-07-24 CH CH966075A patent/CH586954A5/xx not_active IP Right Cessation
- 1975-08-11 DE DE19752535745 patent/DE2535745A1/en not_active Withdrawn
-
1976
- 1976-07-21 FR FR7622197A patent/FR2319185A1/en not_active Withdrawn
- 1976-07-22 JP JP8770576A patent/JPS5214898A/en active Pending
- 1976-07-22 GB GB3067276A patent/GB1531317A/en not_active Expired
- 1976-07-23 CA CA257,605A patent/CA1075567A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105623240A (en) * | 2015-12-17 | 2016-06-01 | 上海交通大学 | Anisotropic high-molecular permanent magnetic compound material and preparation method therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| GB1531317A (en) | 1978-11-08 |
| JPS5214898A (en) | 1977-02-04 |
| CH586954A5 (en) | 1977-04-15 |
| DE2535745A1 (en) | 1977-02-10 |
| FR2319185A1 (en) | 1977-02-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4957668A (en) | Ultrasonic compacting and bonding particles | |
| DE69117298T2 (en) | METHOD AND DEVICE FOR PRODUCING AN OBJECT FROM COMPOSITE MATERIAL | |
| CA1075567A (en) | Method for producing permanent magnets | |
| US3493527A (en) | Moldable composition formed of waste wood or the like | |
| US4562019A (en) | Method of preparing plastomeric magnetic objects | |
| US4902451A (en) | Method of preparing a frictional material | |
| US4609527A (en) | Powder consolidation and machining | |
| EP0223525A3 (en) | Moulding of construction products | |
| JPS63275511A (en) | Molding of powder cosmetic | |
| JPH05335166A (en) | Method and device for manufacturing resin magnet | |
| JPH104023A (en) | Manufacture of bond type permanent magnet | |
| JPS6360082B2 (en) | ||
| JP4399700B2 (en) | Recycling method for waste polyurethane foam | |
| CH680251GA3 (en) | ||
| JPH06314605A (en) | Manufacture of rare earth bonded magnet | |
| JPH09314614A (en) | Injection molding method | |
| SU361102A1 (en) | ALL-UNION I | |
| JPH03190208A (en) | Manufacture of anisotropic bonded magnet | |
| JPH0447446B2 (en) | ||
| WO2000029631A1 (en) | Method for producing soft-magnetic sintered components | |
| US2254254A (en) | Method of molding articles | |
| JPH03151612A (en) | Manufacture of resin-bonded type permanent magnet molded object | |
| ES2048642A1 (en) | Compression process for making briquettes from ferrous alloy particles - using polymeric binders | |
| JPH0531805B2 (en) | ||
| JPH04115505A (en) | Preparation of bond magnet |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |