US3743550A
Expired / Lapsed
US
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Alloys for magnetic recording-reproducing heads
Assignee: Research Institute for Electromagnetic Materials
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Filing: 1971-06-17
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Granted: 1973-07-03
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Expires: 1991-06-17
Abstract
Abstract A ferromagnetic alloy of magnetic recording-reproducing heads, essentially consisting of 70.0 to 84.8 Wt.% of nickel, 5.0 to 25.5 Wt.% of iron, and 3.1 to 14.0 Wt.% of niobium, and having Vickers hardness of above 150 and a high initial permeability and a maximum permeability of above 3,000 and 5,000, respectively, and a degree of order greater than 0.1 but less than 0.6.
Inventors
- 👤 H Masumoto
- 👤 Y Murakami
- 👤 M Hinai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:19
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/14708; C; C22; C22C; C22C19/00; G; G11; G11B; G11B5/00; G11B5/127; G11B5/147
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
32 words
An alloy according to claim 1, wherein the nickel content is 75.3 to 82.2 Wt.%, the iron content is 9.2 to 20.6 Wt.%, and the niobium content is 3.1 to 10.8 Wt.%.
Claim 2
Dependent Claim
32 words
An alloy according to claim 1, wherein the nickel content is 78.3 to 81.8 Wt.%, the iron content is 9.6 to 15.2 Wt.%, and the niobium content is 4.8 to 10.4 Wt.%.
Claim 3
Dependent Claim
32 words
An alloy according to claim 1, wherein the nickel content is 79.0 to 81.4 Wt.%, the iron content is 10.1 to 14.2 Wt.%, and the niobium content is 5.7 to 9.8 Wt.%.
Claim 4
Dependent Claim
22 words
An alloy according to claim 1, wherein the initial permeability is greater than 12,000 and the maximum permeability is greater than 110,000.
Claim 5
Dependent Claim
17 words
An alloy according to claim 1, wherein the electric resistivity is greater than 38 Mu Omega -cm.
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |