US4251293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetically anisotropic alloys by deformation processing
Assignee: AT&T Inc
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Filing: 1979-02-28
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Granted: 1981-02-17
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Expires: 1999-02-28
Abstract
Abstract Magnetic alloys are disclosed having an anisotropic magnetic structure produced by thermomechanical treatment in the absence of a magnetic field. Disclosed treatment calls for developing magnetic particles in an alloy by cooling such alloy in a controlled fashion from a first temperature at which the alloy is in a predominantly single phase state to a second temperature at which the alloy is in a multi-phase state. Treatment further calls for deforming the alloy, resulting in cross-sectional area reduction of at least 30 percent (corresponding to elongation of magnetic particles by a factor of at least 1.7). Disclosed treatment leads to desirable magnetic properties, e.g., in Cu-Ni-Fe, Cu-Ni-Co, Fe-Al-Ni, Fe-Al-Ni-Co, and Fe-Cr-Co alloys. For example, in the case of Fe-Cr-Co, alloy properties such as remanence-to-saturation squareness ratio in excess of 0.90 and maximum energy product in the range of 0.6-8.0 MGOe are achieved. Disclosed magnetic alloys are suitable for use in the manufacture of telephone ringers, relays, and electromagnetic transducers.
Inventors
- 👤 Sungho Jin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 06:31
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/032; H01F1/04; H01F1/06; H01F1/08; C; C22; C22C; C22C38/00; C22C38/18; C22C38/30; H01F41/00; H01F41/02; H01F41/0206
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
169 words
Method for producing a magnetic element, said method comprising thermo-mechanical treatment of an alloy which has a characteristic temperature, here designated T 1 , such that said alloy is in a solid, predominantly single phase state at temperatures in a first temperature range whose lower limit is T 1 , and such that said alloy is in a multi-phase state at temperatures in a second temperature range whose upper limit is T 1 , characterized in that said treatment comprises the steps of (1) developing in said alloy particles of a strongly magnetic phase by controlled lowering of temperature from a first temperature in said first range to a second temperature in said second range, and (2) developing magnetic anisotropy in said alloy by plastically deforming said alloy so as to result in a cross-sectional area reduction of at least 30 percent while the temperature of said alloy is in said second range, whereby said particles are deformed resulting in a particle thickness in the range of 200-2000 Angstroms.
Claim 2
Dependent Claim
169 words
Method for producing a magnetic element, said method comprising thermo-mechanical treatment of an alloy which has a characteristic temperature, here designated T 1 , such that said alloy is in a solid, predominantly single phase state at temperatures in a first temperature range whose lower limit is T 1 , and such that said alloy is in a multi-phase state at temperatures in a second temperature range whose upper limit is T 1 , characterized in that said treatment comprises the steps of (1) developing in said alloy particles of a strongly magnetic phase by controlled lowering of temperature from a first temperature in said first range to a second temperature in said second range, and (2) developing magnetic anisotropy in said alloy by plastically deforming said alloy so as to result in a cross-sectional area reduction of at least 30 percent while the temperature of said alloy is in said second range, whereby said particles are deformed resulting in a particle thickness in the range of 200-2000 Angstroms.
Claim 3
Dependent Claim
12 words
Method of claim 1 in which said alloy is aged after deforming.
Claim 4
Dependent Claim
21 words
Method of claim 1 in which said alloy is selected from the group consisting of Cu-Ni-Fe, Cu-Ni-Co, Fe-Al-Ni, Fe-Al-Ni-Co, and Fe-Cr-Co.
Claim 5
Dependent Claim
59 words
Method of claim 3 in which an amount of at least 95 weight percent of the composition of said alloy consists of Fe, Cr, and Co, Cr content of said alloy being in the range of 20-40 weight percent of said amount and Co content of said alloy being in the range of 3-20 weight percent of said amount.
Claim 6
Dependent Claim
63 words
Method of claim 4 in which said second temperature is in the range of 575-625 degrees C. and in which the temperature of said alloy is lowered from said first to said second temperature at a rate which over essentially the entire range of temperatures between said first temperature and said second temperature is in the range of 0.5-100.0 degrees C. per hour.
Claim 7
Dependent Claim
67 words
Method of claim 5 in which said alloy, after deforming, is aged by lowering the temperature of said alloy from a second temperature in the range of 575-625 degrees C. to a third temperature in the range of 470-570 degrees C. at a rate which over essentially the entire range of temperatures between said second and said third temperature is less than 30 degrees C. per hour.
Claim 8
Dependent Claim
50 words
Method of claim 4 in which said alloy comprises at least one ferrite forming element selected from the group consisting of 0.1-1 weight percent Zr, 0.1-5 weight percent Mo, 0.1-5 weight percent V, 0.1-3 weight percent Nb, 0.1-3 weight percent Al, 0.1-3 weight percent Si, and 0.1-5 weight percent W.
Claim 9
Dependent Claim
31 words
Method of claim 4 in which said alloy consists essentially of Fe, Cr, and Co, Co content of said alloy being in the range of 5-15 weight percent of said amount.
Claim 10
Dependent Claim
17 words
Method of claim 4 in which said first temperature is in the range of 650-775 degrees C.
Claim 11
Dependent Claim
19 words
Method of claim 1 in which temperature is lowered essentially linearly from said first temperature to said second temperature.
Claim 12
Dependent Claim
19 words
Method of claim 1 in which temperature is lowered essentially exponentially from said first temperature to said second temperature.
Claim 13
Dependent Claim
15 words
Method of claim 1 in which said alloy during deforming is at said second temperature.
Claim 14
Dependent Claim
16 words
Method of claim 4 in which said alloy prior to deforming is quenched to room temperature.
Claim 15
Dependent Claim
15 words
Method of claim 4 in which deforming is carried out by rolling, extrusion, or drawing.
Claim 16
Dependent Claim
43 words
Method of claim 5 in which lowering temperature from said first temperature to said second temperature is at rates which over essentially the entire range of temperatures between said first temperature and said second temperature are in the range of 1-60 degrees C./h.
Claim 17
Dependent Claim
42 words
Method of claim 6 in which lowering temperature from said second temperature to said third temperature is at rates which over essentially the entire range of temperatures between said first temperature and said second temperature are not less than 2 degrees C./h.
Claim 18
Dependent Claim
88 words
Magnetic article comprising a body of an alloy which, upon cooling from a first temperature to a second temperature has undergone a phase transformation from a predominantly single phase state to a multi-phase state, said multi-phase state being a predominantly spinodal state, said alloy having a Curie temperature and a spinodal temperature, said Curie temperature being less than said spinodal temperature and characterized in that spinodal structure and grains of said alloy are elongated so as to have an aspect ratio in the range of 1:1.7 to 1:20.
Claim 19
Dependent Claim
88 words
Magnetic article comprising a body of an alloy which, upon cooling from a first temperature to a second temperature has undergone a phase transformation from a predominantly single phase state to a multi-phase state, said multi-phase state being a predominantly spinodal state, said alloy having a Curie temperature and a spinodal temperature, said Curie temperature being less than said spinodal temperature and characterized in that spinodal structure and grains of said alloy are elongated so as to have an aspect ratio in the range of 1:1.7 to 1:20.
Claim 20
Dependent Claim
19 words
Article of claim 17 in which Curie temperature is less than spinodal temperature by at least 20 degrees C.
Claim 21
Dependent Claim
26 words
Article of claim 17 in which an amount of at least 95 weight percent of the composition of said alloy consists of Fe, Cr, and Co.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-17 | 1984-08-18 | 1985-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-17 | 1988-08-18 | 1989-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-17 | 1992-08-18 | 1993-02-17 | $7700.00 | Window Closed / Lapsed |