US3855691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a magnetic material part with spatial distribution of the permeability
Assignee: Lignes Telegraphiques et Telephoniques LTT SA
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Filing: 1973-03-02
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Granted: 1974-12-24
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Expires: 1993-03-02
Abstract
Abstract A part made of ferrimagnetic material with a spatial variation of the permeability value is obtained through heat treatment of a body of ferrimagnetic material at the temperture such that the free energy of the material is low and that a transformation into a material with higher free energy is obtained, stopping said heating before complete transformation and further machining of the part. The heat treatment is carried out under reduced pressure when a liquid phase develops at the heating temperature. When solid phase is maintained the body is heated in presence of a metal salt or oxide.
Inventors
- 👤 A Deschamps
- 👤 G Faye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:44
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/34; H01F1/36; H01F1/37; C; C04; C04B; C04B35/00; C04B35/01; C04B35/26; C04B35/265; C04B35/2675; H01F1/0302; H01F1/0311; H01P; H01P1/00; H01P1/32; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49075; Y10T29/49076
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
89 words
A PROCESS FOR THE MANUFACTURE OF A SOLID MAGNETIC ARTICLE WITH A SPATIALLY UNEVEN DISTRIBUTION OF PERMEABILITY WHICH COMPRISES: PROVIDING A SINTERED SOLID PIECE OF POLYCRYSTALLINE MAGNETICALLY UNCOMPENSATED INITIAL F1 MATERIAL HAVING A FIRST PERMEABILITY VALUE HEATING SAID SINTERED SOLID PIECE AT A TEMPERATURE SUCH THAT THE FREE ENERGY OF SAID F1 MATERIAL IS SMALLER THAN THE FREE ENERGY OF ANOTHER FERRIMAGNETIC F2 MATERIAL HAVING A SECOND PERMEABILITY VALUE DIFFERENT FROM SAID FIRST PERMEABILITY VALUE, TRANSFORMING AT SAID TEMPERAURE A PORTION OF SAID F1 MATERIAL INTO SAID F2 MATERIAL,
Claim 2
Dependent Claim
89 words
A PROCESS FOR THE MANUFACTURE OF A SOLID MAGNETIC ARTICLE WITH A SPATIALLY UNEVEN DISTRIBUTION OF PERMEABILITY WHICH COMPRISES: PROVIDING A SINTERED SOLID PIECE OF POLYCRYSTALLINE MAGNETICALLY UNCOMPENSATED INITIAL F1 MATERIAL HAVING A FIRST PERMEABILITY VALUE HEATING SAID SINTERED SOLID PIECE AT A TEMPERATURE SUCH THAT THE FREE ENERGY OF SAID F1 MATERIAL IS SMALLER THAN THE FREE ENERGY OF ANOTHER FERRIMAGNETIC F2 MATERIAL HAVING A SECOND PERMEABILITY VALUE DIFFERENT FROM SAID FIRST PERMEABILITY VALUE, TRANSFORMING AT SAID TEMPERAURE A PORTION OF SAID F1 MATERIAL INTO SAID F2 MATERIAL,
Claim 3
Dependent Claim
49 words
A process for the manufacture of a solid magnetic article with a spatially uneven distribution of the permeability according to claim 1 in which a liquid phase of different chemical composition develops at the heating temperature, the chemical composition of which differs from that of the initial I1 material.
Claim 4
Dependent Claim
15 words
A process according to claim 2 in which said heating is made under reduced pressure.
Claim 5
Dependent Claim
46 words
A process for the manufacture of a solid magnetic article with a spatially uneven distribution of permeability according to claim 3 in which said initial F1 material is an yttrium iron Gd, Al substituted garnet and said heating temperature is between 1, 250* and 1350* C.
Claim 6
Dependent Claim
45 words
A process for the manufacture of a solid magnetic article with a spatially uneven distribution of permeability according to claim 3 in which said initial F1 material is a Ni - Zn spinel ferrite and said heating temperature is between 1,270* and 1, 310* C.
Claim 7
Dependent Claim
56 words
A process for the manufacture of a solid magnetic article with a spatially uneven distribution of the permeability according to claim 1 in which said heating is carried on at a temperature lower than the liquefaction of the F1 material in presence of a salt of a foreign metal which constitutes the F2 material through substitution.
Claim 8
Dependent Claim
48 words
A process for the manufacture of a solid magnetic article with a spatially uneven permeability distribution according to claim 6 in which said initial material is nickel spinel, the metal ion of said salt of foreign metal is divalent zinc and said heating temperature is above 850* C.
Claim 9
Dependent Claim
48 words
A process for the manufacture of a solid magnetic article with a spatially uneven permeability distribution according to claim 6 in which said initial material is nickel spinel, the metal ion of said salt of foreign metal is divalent copper and said heating temperature is above 850* C.
Claim 10
Dependent Claim
48 words
A process for the manufacture of a solid magnetic article with a spatially uneven permeability distribution according to claim 6 in which said initial material is nickel spinel, the metal ion of said salt of foreign metal is divalent boron and said heating temperature is above 850* C.
Claim 11
Dependent Claim
49 words
A process for the manufacture of a solid magnetic article with a spatially uneven permeability distribution according to claim 6 in which said initial material is an yttrium-iron garnet the metal ion of said salt of foreign metal is divalent boron and said heating temperature is above 1,200* C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |