Patent US4023991A successfully refreshed from Google Patents.
US4023991A
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Anisotropic permanent magnet of Mn-Al-C alloy
Assignee: Panasonic Holdings Corp
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Filing: 1976-06-01
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Granted: 1977-05-17
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Expires: 1996-06-01
Abstract
Abstract An anisotropic permanent magnet of an Mn-Al-C alloy containing 68.0% to 73.0% by weight of manganese, (1/10Mn-6.6)% to (1/3Mn-22.2)% by weight of carbon, and the remainder aluminum, which alloy is rendered anisotropic by deforming it plastically at a temperature of 530 DEG to 830 DEG C.
Inventors
- 👤 Takao Kubo
- 👤 Tadao Ohtani
- 👤 Shigeru Kojima
- 👤 Nobuyuki Kato
- 👤 Kiyoshi Kojima
- 👤 Yoichi Sakamoto
- 👤 Isago Konno
- 👤 Masaharu Tsukahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:12
CPC Classifications
C; C22; C22C; C22C28/00; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
57 words
A method of making an anisotropic permanent magnet comprising the steps of subjecting an alloy comprising 68.0% to 73.0% by weight of manganese, (1/10 Mn-6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to plastic deformation at a temperature of 530° to 830° C in order to make the alloy magnetically anisotropic.
Claim 2
Independent Claim
57 words
A method of making an anisotropic permanent magnet comprising the steps of subjecting an alloy comprising 68.0% to 73.0% by weight of manganese, (1/10 Mn-6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to plastic deformation at a temperature of 530° to 830° C in order to make the alloy magnetically anisotropic.
Claim 3
Dependent Claim
23 words
A method according to claim 1 further comprising the step of tempering the deformed alloy at a temperature of 480° to 750° C.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein the alloy in the step before deformation has a hexagonal phase.
Claim 5
Dependent Claim
18 words
A method according to claim 1, wherein the alloy in the step before deformation has a orthorhombic phase.
Claim 6
Dependent Claim
17 words
A method according to claim 3, wherein the alloy of the hexagonal phase is a single crystal.
Claim 7
Dependent Claim
32 words
A method according to claim 5, wherein the single crystal contains lamellae of a compound Mn 3 AlC and/or a face-centered cubic phase which is similar to the compound Mn 3 AlC.
Claim 8
Dependent Claim
30 words
A method of according to claim 5, wherein a crystal direction of the single crystal is determined by utilizing the orientation between the matrix of the crystal and the lamellae.
Claim 9
Independent Claim
96 words
A method of making an anisotropic permanent magnet, comprising the steps of subjecting an alloy comprising the composition of 68.0% to 73.0% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to the steps of: a. precipitating lamellae of a compound Mn 3 AlC and/or a face-centered cubic phase which is similar to the compound Mn 3 AlC in the alloy; and then b. deforming plastically the alloy at a temperature of 530° to 830° C in order to make the alloy magnetically anisotropic.
Claim 10
Independent Claim
96 words
A method of making an anisotropic permanent magnet, comprising the steps of subjecting an alloy comprising the composition of 68.0% to 73.0% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to the steps of: a. precipitating lamellae of a compound Mn 3 AlC and/or a face-centered cubic phase which is similar to the compound Mn 3 AlC in the alloy; and then b. deforming plastically the alloy at a temperature of 530° to 830° C in order to make the alloy magnetically anisotropic.
Claim 11
Dependent Claim
23 words
A method according to claim 8, further comprising the step of tempering the deformed alloy at a temperature of 480° to 750° C.
Claim 12
Dependent Claim
31 words
A method according to claim 8, wherein the precipitating step (a) is performed by cooling the alloy from 900° to 830° C at a cooling rate of 10° C/min. or less.
Claim 13
Dependent Claim
32 words
A method according to claim 8, wherein the precipitating step (a) is performed by holding the alloy at a temperature of 830° to less than 900° C for 7 minutes or more.
Claim 14
Independent Claim
63 words
A method of making an anisotropic permanent magnet, comprising the steps of subjecting an alloy comprising the composition of 68.0% to 70.5% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to plastic deformation at a temperature of 600° C to 780° C in order to make the alloy magnetically anisotropic.
Claim 15
Independent Claim
63 words
A method of making an anisotropic permanent magnet, comprising the steps of subjecting an alloy comprising the composition of 68.0% to 70.5% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to plastic deformation at a temperature of 600° C to 780° C in order to make the alloy magnetically anisotropic.
Claim 16
Dependent Claim
23 words
A method according to claim 12, further comprising the step of tempering the deformed alloy at a temperature of 480° to 750° C.
Claim 17
Independent Claim
78 words
A method of making an anisotropic permanent magnet comprising the steps of subjecting an alloy comprising the composition of 68.0% to 70.5% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to: a. quenching at a temperature of from 900° C or more; b. deforming plastically the quenched alloy at a temperature of 600° C to 780° C in order to make the alloy magnetically anisotropic.
Claim 18
Independent Claim
78 words
A method of making an anisotropic permanent magnet comprising the steps of subjecting an alloy comprising the composition of 68.0% to 70.5% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum to: a. quenching at a temperature of from 900° C or more; b. deforming plastically the quenched alloy at a temperature of 600° C to 780° C in order to make the alloy magnetically anisotropic.
Claim 19
Dependent Claim
23 words
A method according to claim 14, further comprising the step of tempering the deformed alloy at a temperature of 480° to 750° C.
Claim 20
Independent Claim
78 words
A method of making an anisotropic permanent magnet having a predetermined shape, comprising the steps of forming an alloy comprising the composition of 68.0% to 73.0% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum into predetermined shape by deforming plastically the alloy at a temperature of 530° C to 830° C in order to make the alloy magnetically anisotropic in one or more preferred directions.
Claim 21
Independent Claim
78 words
A method of making an anisotropic permanent magnet having a predetermined shape, comprising the steps of forming an alloy comprising the composition of 68.0% to 73.0% by weight of manganese, (1/10 Mn - 6.6)% to (1/3 Mn - 22.2)% by weight of carbon and the remainder aluminum into predetermined shape by deforming plastically the alloy at a temperature of 530° C to 830° C in order to make the alloy magnetically anisotropic in one or more preferred directions.
Claim 22
Dependent Claim
23 words
A method according to claim 16, further comprising the step of tempering the formed alloy at a temperature of 480° to 750° C.
Claim 23
Dependent Claim
25 words
A method according to claim 14, further comprising the step of tempering the quenched alloy at a temperature of 480° to 750° C before deformation.
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) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |