US4437907A
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Amorphous alloy for use as a core
Assignee: Nippon Steel Corp
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Filing: 1982-03-05
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Granted: 1984-03-20
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Expires: 2002-03-05
Abstract
Abstract Amorphous alloys have attractive properties which make possible their use as cores for transformers, these properties being a low watt loss, which is due to an inherently low magnetic anisotropy, and a high resistivity. However, one of the most serious disadvantages of amorphous alloys is the low thermal stability of the magnetic properties and the fact that their magnetic properties, such as saturation flux density (Bs), decrease at the temperature of the energized or excited core. In order to eliminate the disadvantages of the known amorphous alloys, the present invention proposes an amorphous alloy having a composition of Fe74-80 Si8-19 B6-13 C0-3.5. This alloy is specifically adapted so that it can be used as a transformer core which can be energized or excited at a high flux density.
Inventors
- 👤 Takashi Sato
- 👤 Tsutomu Ozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 22:03
CPC Classifications
C; C22; C22C; C22C45/00; C22C45/02; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/147; H01F1/153; H01F1/15308
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
167 words
An annealed amorphous alloy for use as the core of electric-power transforming machines and devices, wherein said annealed alloy has an essentially amorphous structure, an extremely low watt loss, a high thermal stability in respect to the magnetic properties and amorphous structure, a small change in the magnetic properties depending upon the temperature, and exhibits a very low increase in watt loss and a very low decrease in magnetic flux density after aging, and is composed of the chemical formula of Fe a Si b B c C d , said parameters a, b, c, and d being the following atomic percentages: a=from 74 to 79% b=from 10 to 19% c=from 6 to 13% d=from 0 to 3.5% with the proviso that a+b+c+d=100%; wherein the decrease in magnetic flux density after annealing in terms of: ##EQU4## does not exceed 3%, and, wherein said alloy is annealed at a temperature of from 350° to 430° C. in a magnetic field higher than the coercive force of said alloy.
Claim 2
Dependent Claim
167 words
An annealed amorphous alloy for use as the core of electric-power transforming machines and devices, wherein said annealed alloy has an essentially amorphous structure, an extremely low watt loss, a high thermal stability in respect to the magnetic properties and amorphous structure, a small change in the magnetic properties depending upon the temperature, and exhibits a very low increase in watt loss and a very low decrease in magnetic flux density after aging, and is composed of the chemical formula of Fe a Si b B c C d , said parameters a, b, c, and d being the following atomic percentages: a=from 74 to 79% b=from 10 to 19% c=from 6 to 13% d=from 0 to 3.5% with the proviso that a+b+c+d=100%; wherein the decrease in magnetic flux density after annealing in terms of: ##EQU4## does not exceed 3%, and, wherein said alloy is annealed at a temperature of from 350° to 430° C. in a magnetic field higher than the coercive force of said alloy.
Claim 3
Dependent Claim
15 words
An alloy according to claim 1 wherein said annealing temperature is higher than 385° C.
Claim 4
Dependent Claim
19 words
An amorphous alloy according to claim 1 or 2 wherein the iron percentage (a) is from 76 to 79%.
Claim 5
Dependent Claim
19 words
An amorphous alloy according to claim 1 or 2 wherein the silicon percentage (b) is from 10 to 17%.
Claim 6
Dependent Claim
17 words
An amorphous alloy according to claim 3 wherein the silicon percentage (b) is from 10 to 13%.
Claim 7
Dependent Claim
17 words
An amorphous alloy according to claim 5 wherein the boron percentage (c) is from 7 to 9.9%.
Claim 8
Dependent Claim
17 words
An amorphous alloy according to claim 3 wherein the carbon percentage (d) is from 0 to 2.0%.
Claim 9
Dependent Claim
18 words
An amorphous alloy according to claim 1 or 2 wherein the carbon percentage is from 0.5 to 2.0%.
Claim 10
Dependent Claim
24 words
An amorphous alloy according to claim 1 or 2 wherein said alloy is composed of Fe 78 Si 10 B 10 C 2 .
Claim 11
Dependent Claim
17 words
An amorphous alloy according to claim 7 wherein the boron percentage (c) is from 7 to 9.9%.
Claim 12
Dependent Claim
17 words
An amorphous alloy according to claim 4 wherein the carbon percentage (d) is from 0 to 2.0%.
Claim 13
Dependent Claim
17 words
An amorphous alloy according to claim 6 wherein the carbon percentage (d) is from 0.5 to 2.0%.
Claim 14
Dependent Claim
38 words
An amorphous alloy according to claim 1 or 2, wherein the silicon content (b) is from 10 to 13%, the boron content (c) is from 7 to 9.9%, and the carbon content (d) is from 0.5 to 2.0%.
Claim 15
Dependent Claim
24 words
An amorphous alloy according to claim 1 or 2 wherein said alloy is composed of Fe 78 Si 13 B 8 C 1 .
Claim 16
Dependent Claim
22 words
An amorphous alloy according to claim 1 wherein said alloy is composed of Fe 78 Si 12 B 9 C 1 .
Claim 17
Dependent Claim
28 words
An amorphous alloy according to claim 1 or 2 wherein the increase in watt loss (W 12 .6/50) after annealing in terms of: ##EQU5## does not exceed 10%.
Claim 18
Dependent Claim
27 words
An amorphous alloy according to claim 2 wherein said alloy is annealed at a temperature of up to 410° C. with the application of a magnetic field.
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) | 1987-03-20 | 1987-09-19 | 1988-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-20 | 1991-09-19 | 1992-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-20 | 1995-09-19 | 1996-03-20 | $7700.00 | Window Closed / Lapsed |