US4420348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Amorphous alloy for magnetic head core
Assignee: Hitachi Ltd
•
Filing: 1981-03-27
•
Granted: 1983-12-13
•
Expires: 2001-03-27
Abstract
Abstract Amorphous alloy for magnetic head core represented by the general formula, (FexCo1-x)a CrbSic-B1-a-b-c, where the value of x is 0.04-0.07, the value of a is 0.73-0.75, the value of b is 0.005-0.03, and the value of c is 0.02-0.06. The present amorphous alloy has high permeability, high saturation flux density, low magnetostriction, and low magnetic after-effect at the same time, and has distinguished characteristics for magnetic head core.
Inventors
- 👤 Kazuo Shiiki
- 👤 Shigekazu Otomo
- 👤 Mitsuhiro Kudo
- 👤 Mitsuo Abe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:32
CPC Classifications
C; C22; C22C; C22C45/00; C22C45/008; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/153; H01F1/15316
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
81 words
Amorphous alloy for magnetic head core, represented by the general formula: (Fe.sub.x Co.sub.1-x).sub.a Cr.sub.b Si.sub.c B.sub.1-a-b-c wherein the value of x is 0.04-0.07, the value of a is 0.73-0.75, the value of b is 0.005-0.03, and the value of c is 0.02-0.06, whereby said alloy has a saturation flux density of 8 kG or higher, permeability of more than 5000 at 20 kHz and magnetostriction of less than 10 -6 such that said alloy can be utilized for magnetic head cores.
Claim 2
Dependent Claim
81 words
Amorphous alloy for magnetic head core, represented by the general formula: (Fe.sub.x Co.sub.1-x).sub.a Cr.sub.b Si.sub.c B.sub.1-a-b-c wherein the value of x is 0.04-0.07, the value of a is 0.73-0.75, the value of b is 0.005-0.03, and the value of c is 0.02-0.06, whereby said alloy has a saturation flux density of 8 kG or higher, permeability of more than 5000 at 20 kHz and magnetostriction of less than 10 -6 such that said alloy can be utilized for magnetic head cores.
Claim 3
Dependent Claim
17 words
Amorphous alloy for magnetic head core according to claim 1, wherein the value of x is 0.048-0.065.
Claim 4
Dependent Claim
17 words
Amorphous alloy for magnetic head core according to claim 1, wherein the value of x is 0.052-0.061.
Claim 5
Dependent Claim
20 words
Amorphous alloy for magnetic head core according to claim 1, 2 or 3, wherein the value of b is 0.01-0.025.
Claim 6
Dependent Claim
21 words
Amorphous alloy for magnetic head core according to claim 1, 2 or 3, wherein the value of b is about 0.02.
Claim 7
Dependent Claim
43 words
Amorphous alloy for magnetic head core according to claim 1, wherein the amorphous alloy has been heated at 450°-500° C. for 3-60 minutes and then cooled at a cooling speed of at least 20° C./sec, whereby said amorphous alloy has an increased permeability.
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) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |