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US4093477A
Expired / Lapsed
US
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Anisotropic permanent magnet alloy and a process for the production thereof
Assignee: Proterial Ltd
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Filing: 1976-11-01
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Granted: 1978-06-06
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Expires: 1996-11-01
Abstract
Abstract The thermo-magnetic-treated anisotropic permanent magnet alloy of the present invention consists essentially of, by weight, 17 to 45% chromium, 3 to 14.5% cobalt, 0.2 to 5% silicon and balance substantially iron, preferably 23 to 35% chromium, 7 to 14.5% of cobalt, 0.3 to 3% silicon and balance substantially iron and has a residual magnetic flux density of 7000 Gauss or more and a coersive force of 300 Oersted or more. In order to obtain the alloy, an alloy having the above identified composition is initially aged at a temperature of 570° C to 670° C for a period of 10 minutes to 5 hours in a magnetic field and secondarily aged at a temperature within 200° C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Inventors
- 👤 Masao Iwata
- 👤 Hisao Yoshizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 10:32
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; C; C21; C21D; C21D1/00; C21D1/04; C22; C22C; C22C38/00; C22C38/18; C22C38/30
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
127 words
A thermo-magnetic-treated anisotropic permanent magnet alloy having a residual magnetic flux density of 7,000 Gauss or more and a coercive force of 300 Oersted or more, said anisotropic permanent magnet alloy being prepared by subjecting an alloy consisting essentially of 17 to 45% by weight of chromium, 3 to 14.5% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron to a solution treatment at 600° to 1300° C., heating the alloy in a magnetic field at a temperature of 570° to 670° C. for a period of 10 minutes to 5 hours, and then aging the thermo-magnetic treated alloy at a temperature within 200° C. below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 2
Dependent Claim
127 words
A thermo-magnetic-treated anisotropic permanent magnet alloy having a residual magnetic flux density of 7,000 Gauss or more and a coercive force of 300 Oersted or more, said anisotropic permanent magnet alloy being prepared by subjecting an alloy consisting essentially of 17 to 45% by weight of chromium, 3 to 14.5% by weight of cobalt, 0.2 to 5% by weight of silicon and a balance of substantially iron to a solution treatment at 600° to 1300° C., heating the alloy in a magnetic field at a temperature of 570° to 670° C. for a period of 10 minutes to 5 hours, and then aging the thermo-magnetic treated alloy at a temperature within 200° C. below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 3
Dependent Claim
68 words
The thermo-magnetic-treated anisotropic permanent magnet alloy as set forth in claim 1, wherein the anisotropic magnetic alloy has a residual magnetic flux density of 9,000 Gauss or more and a coercive force of 400 Oersted or more and consists essentially of 23 to 35% by weight of chromium, 7 to 14.5% by weight of cobalt, 0.3 to 3% by weight of silicon and a balance of substantially iron.
Claim 4
Dependent Claim
34 words
The thermo-magnetic-treated anisotropic permanent magnet alloy as set forth in claim 1, wherein the anisotropic permanent magnetic alloy further contains up to 5% by weight of sum of manganese, molybdenum, magnesium, calcium and vanadium.
Claim 5
Dependent Claim
34 words
The thermo-magnetic-treated anisotropic permanent magnetic alloy as set forth in claim 2, wherein the anisotropic permanent magnet alloy further contains up to 5% by weight of sum of manganese, molybdenum, magnesium, calcium and vanadium.
Claim 6
Dependent Claim
136 words
A process for producing an anisotropic permanent magnet alloy having a residual magnetic flux density of 7,000 Gauss or more and a coercive force of 300 Oersted or more which comprises subjecting an alloy consisting essentially of 17 to 45% by weight of chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon, up to 5% by weight of the sum of manganese, molybdenum, magnesium, calcium and vanadium and a balance of substantially iron to a solution treatment at 600° to 1300° C., heating the alloy at 570° to 670° C., in a magnetic field for a period of 10 minutes to 5 hours and then aging the thermo-magnetic treated alloy at a temperature within 200° C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 7
Dependent Claim
136 words
A process for producing an anisotropic permanent magnet alloy having a residual magnetic flux density of 7,000 Gauss or more and a coercive force of 300 Oersted or more which comprises subjecting an alloy consisting essentially of 17 to 45% by weight of chromium, 3 to 14% by weight of cobalt, 0.2 to 5% by weight of silicon, up to 5% by weight of the sum of manganese, molybdenum, magnesium, calcium and vanadium and a balance of substantially iron to a solution treatment at 600° to 1300° C., heating the alloy at 570° to 670° C., in a magnetic field for a period of 10 minutes to 5 hours and then aging the thermo-magnetic treated alloy at a temperature within 200° C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 8
Dependent Claim
32 words
The process as set forth in claim 5, wherein said alloy is thermo-magnetic treated at a temperature of 590° C to 650° C for a period of 10 minutes to 5 hours.
Claim 9
Dependent Claim
26 words
The process as set forth in claim 5, wherein said alloy is aged by gradual reduction in temperature within 200° C below the thermo-magnetic treatment temperature.
Claim 10
Dependent Claim
44 words
The process as set forth in claim 7, wherein said alloy is aged by continuously cooling, by more than 10° C, within 200° C below the thermo-magnetic treatment temperature at a cooling rate of 5 minutes to 50 hours for a 10° C drop.
Claim 11
Dependent Claim
23 words
The process as set forth in claim 8, wherein the cooling rate is 15 minutes to 10 hours for a 10° C drop.
Claim 12
Dependent Claim
23 words
The process as set forth in claim 9, wherein the cooling rate is 30 minutes to 5 hours for a 10° C drop.
Claim 13
Dependent Claim
38 words
The process as set forth in claim 7, wherein said alloy is aged by continuously cooling from about 600° to about 500° C at a cooling rate of 10 hours to 20 hours for a 100° C drop.
Claim 14
Dependent Claim
139 words
A process for producing an anisotropic permanent magnet alloy having a residual magnetic flux density of 9,000 Gauss or more and a coercive force of 400 Oersted or more which comprises subjecting an alloy consisting essentially of 23 to 35% by weight of chromium, 7 to 14.5% by weight of cobalt, 0.3 to 3% by weight of silicon, up to 5% by weight of the sum of manganese, molybdenum, magnesium, calcium and vanadium and a balance of substantially iron, to a solution treatment at 600° to 1300° C., heating the alloy in a magnetic field at a temperature of 570° to 670° C for a period of 10 minutes to 5 hours and then aging the thermo-magnetic treated alloy at a temperature within 200° C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 15
Dependent Claim
139 words
A process for producing an anisotropic permanent magnet alloy having a residual magnetic flux density of 9,000 Gauss or more and a coercive force of 400 Oersted or more which comprises subjecting an alloy consisting essentially of 23 to 35% by weight of chromium, 7 to 14.5% by weight of cobalt, 0.3 to 3% by weight of silicon, up to 5% by weight of the sum of manganese, molybdenum, magnesium, calcium and vanadium and a balance of substantially iron, to a solution treatment at 600° to 1300° C., heating the alloy in a magnetic field at a temperature of 570° to 670° C for a period of 10 minutes to 5 hours and then aging the thermo-magnetic treated alloy at a temperature within 200° C below the thermo-magnetic treatment temperature for a period of 30 minutes to 50 hours.
Claim 16
Dependent Claim
31 words
The process as set forth in claim 12, wherein said alloy is thermo-magnetic treated at a temperature of 590° to 650° C for a period of 10 minutes to 5 hours.
Claim 17
Dependent Claim
26 words
The process as set forth in claim 12, wherein said alloy is aged by gradual reduction in temperature within 200° C below the thermo-magnetic treatment temperature.
Claim 18
Dependent Claim
44 words
The process as set forth in claim 14, wherein said alloy is aged by continuously cooling, by more than 10° C, within 200° C below the thermo-magnetic treatment temperature at a cooling rate of 5 minutes to 50 hours for a 10° C drop.
Claim 19
Dependent Claim
23 words
The process as set forth in claim 15, wherein the cooling rate is 15 minutes to 10 hours for a 10° C drop.
Claim 20
Dependent Claim
23 words
The process as set forth in claim 16, wherein the cooling rate is 30 minutes to 5 hours for a 10° C drop.
Claim 21
Dependent Claim
37 words
The process a set forth in claim 14, wherein said alloy is aged by continuously cooling from about 600° to 500° C at a cooling rate of 10 hours to 20 hours for a 100° C drop.
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) | 1981-06-05 | 1981-12-05 | 1982-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-05 | 1985-12-05 | 1986-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-05 | 1989-12-05 | 1990-06-06 | $7700.00 | Window Closed / Lapsed |