Patent US4366007A successfully refreshed from Google Patents.
US4366007A
Expired / Lapsed
US
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Permanent magnet and process for making same
Assignee: Japan Kinoko Research Center Foundation
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Filing: 1981-02-20
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Granted: 1982-12-28
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Expires: 2001-02-20
Abstract
Abstract A method of making a hard or semihard magnetic alloy which involves initially forming a body of a spinodally decomposable alloy composition of iron-chromium-cobalt base by casting an admixture of 3 to 30% by weight cobalt, 10 to 40% by weight chromium, 0.1 to 15% by weight vanadium and the balance iron. The body is then solution treated at an elevated temperature and for a period sufficient to produce a homogeneous single α-phase structure in the body and the solution-treated body is tempered at a reduced temperature and for a time period sufficient to spinodally decompose therein the single α-phase structure into a composition-modulated, phase-separated structure consisting of an α 1 phase which is magnetic and an α 2 phase which is nonmagnetic, said phase-separated structure forming the magnetic alloy.
Inventors
- 👤 Kiyoshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:34
CPC Classifications
C; C22; C22C; C22C38/00; C22C38/18; C22C38/30; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
130 words
A method of making a hard or semihard magnetic alloy which comprises the steps of: (A) forming a body of a spinodally decomposable alloy composition of iron-chromium-cobalt base by casting an admixture of 3 to 30% by weight cobalt, 10 to 40% by weight chromium, 0.1 to 15% by weight vanadium and the balance iron; (B) solution-treating said body at an elevated temperature and for a period sufficient to produce a homogeneous single α-phase structure in said body; and (C) tempering the solution-treated body at a reduced temperature and for a time period sufficient to spinodally decompose therein said single α-phase structure into a phase-separated structure consisting of an α 1 -phase which is magnetic and an α 2 phase which is nonmagnetic, said phase-separated structure forming said magnetic alloy.
Claim 2
Independent Claim
130 words
A method of making a hard or semihard magnetic alloy which comprises the steps of: (A) forming a body of a spinodally decomposable alloy composition of iron-chromium-cobalt base by casting an admixture of 3 to 30% by weight cobalt, 10 to 40% by weight chromium, 0.1 to 15% by weight vanadium and the balance iron; (B) solution-treating said body at an elevated temperature and for a period sufficient to produce a homogeneous single α-phase structure in said body; and (C) tempering the solution-treated body at a reduced temperature and for a time period sufficient to spinodally decompose therein said single α-phase structure into a phase-separated structure consisting of an α 1 -phase which is magnetic and an α 2 phase which is nonmagnetic, said phase-separated structure forming said magnetic alloy.
Claim 3
Dependent Claim
33 words
The method defined in claim 1, further comprising the steps of disintegrating said cast body into a powdery form and then compacting the disintegrated body into a coherent form prior to step (B).
Claim 4
Dependent Claim
32 words
The method defined in claim 2 wherein said admixture contains 5 to 25% by weight cobalt, 15 to 35% by weight chromium, 0.5 to 10% by weight vanadium and the balance iron.
Claim 5
Dependent Claim
28 words
The method defined in claim 1, claim 2 or claim 3, further comprising the step of cold-working said body subsequent to step (A) and prior to step (B).
Claim 6
Dependent Claim
32 words
The method defined in claim 1 wherein said admixture contains 5 to 25% by weight cobalt, 15 to 35% by weight chromium, 0.5 to 10% by weight vanadium and the balance iron.
Claim 7
Dependent Claim
37 words
The method defined in claim 1, claim 2, claim 3 or claim 5 wherein step (C) includes: isothermally tempering the solution-treated body in a magnetic field and step-tempering the magnetically tempered body at successively decreased different temperatures.
Claim 8
Dependent Claim
23 words
The method defined in claim 6, further comprising the step of cold-working said body subsequent to step (A) and prior to step (B).
Claim 9
Dependent Claim
23 words
The method defined in claim 6, further comprising the step of hot-working said body subsequent to step (A) and prior to step (B).
References Cited (Backward Citations)
DE638652C
Cited
DE693510C
Cited
SU164029A1
Cited
US3600162A
Cited
JPS4820683B1
Cited
US3588764A
Cited
US3806336A
Cited
JPS4915522A
Cited
JPS50101217A
Cited
US3986867A
Cited
US3954519A
Cited
JPS515612A
Cited
US4008105A
Cited
US4171978A
Cited
US4075437A
Cited
US4093477A
Cited
US4174983A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-27 | 1986-06-28 | 1986-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-27 | 1990-06-28 | 1990-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-27 | 1994-06-28 | 1994-12-28 | $7700.00 | Window Closed / Lapsed |