US4812181A
Expired / Lapsed
US
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Method of achieving a flat magnetization loop in amorphous cores by heat treatment
Assignee: Vacuumschmelze GmbH and Co KG
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Filing: 1987-03-16
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Granted: 1989-03-14
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Expires: 2007-03-16
Abstract
Abstract A method for achieving a flat magnetization loop in cores, such as for use in inductive components, which are wound of amorphous ribbon includes the steps of subjecting the wound core to long-term heat treatment of more than 10 hours, and selecting the temperature during the heat treatment so low that less than half of the ribbon cross-section exhibits crystalline precipitations which occur during the heat treatment.
Inventors
- 👤 Hans-Rainer Hilzinger
- 👤 Giselher Herzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:56
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/153; H01F1/15341; C; C21; C21D; C21D6/00; C21D6/008
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
98 words
A method for achieving a flat magnetization loop in a core wound of amorphous ribbon adaptable for use in a inductive component, said method comprising the steps of: subjecting said core to a long-term heat treatment of more than 10 hours at a temperature greater than 410° C. and so far below the crystallization temperature of said amorphous ribbon to produce crystalline precipitation prodominantly at a surface of said ribbon; and selecting the temperature during said heat treatment so low such that less than half of the ribbon cross-section exhibits crystalline precipitations at the conclusion of the treatment.
Claim 2
Independent Claim
98 words
A method for achieving a flat magnetization loop in a core wound of amorphous ribbon adaptable for use in a inductive component, said method comprising the steps of: subjecting said core to a long-term heat treatment of more than 10 hours at a temperature greater than 410° C. and so far below the crystallization temperature of said amorphous ribbon to produce crystalline precipitation prodominantly at a surface of said ribbon; and selecting the temperature during said heat treatment so low such that less than half of the ribbon cross-section exhibits crystalline precipitations at the conclusion of the treatment.
Claim 3
Dependent Claim
34 words
A method as claimed in claim 1, comprising the additional step of selecting an alloy for said amorphous ribbon having greater than 60 atom percent iron thereby achieving a saturation induction above 1.2 Tesla.
Claim 4
Dependent Claim
48 words
A method as claimed in claim 1, wherein the step of subjecting said core to heat treatment is further defined by subjecting said core to a long-term heat treatment of more than 30 hours, thereby achieving a relative permeability below 500 and a coercive field strength below 5A/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) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |