US4047983A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing soft magnetic material
Assignee: KEYSTONE CARBON COMPANY A PA CORP
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Filing: 1975-04-24
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Granted: 1977-09-13
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Expires: 1995-04-24
Abstract
Abstract A method for producing a soft magnetic material consisting essentially of up to 0.05% carbon, up to 1.0% manganese, up to 0.05% sulfur, up to 0.5% silicon, from 0.5 to 1.5% phosphorus, balance iron and residuals. The method comprises the steps of: blending iron powder and phosphorus-bearing powder into a mixture containing from 0.5 to 1.5% phosphorus; pressing the blended mixture; and sintering the mixture in a non-oxidizing atmosphere at a temperature and for a period of time sufficient to produce a density of at least 7 grams per cubic centimeter. The sintering temperature is at least 2200° F. The soft magnetic material is characterized by a magnetizing force to reach 10 kilogauss of no more than 2.0 oersteds, and a coercive force from 10 kilogauss of no more than 0.9 oersted.
Inventors
- 👤 Edward C. Falkowski
- 👤 Carl E. Ruppel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:59
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0207; C22C33/0214; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/12; H01F1/14; H01F1/20; H01F1/22
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
142 words
A process for producing a phosphorus containing iron soft magnetic material consisting essentially of iron up to 0.05% carbon, up to 1.0% manganese, up to 0.05% sulfur, up to 0.5% silicon, and from 0.5 to 1.5% phosphorus, which comprises the steps of: blending iron powder and ferro phosphorus powder containing from 22 to 30% phosphorus into a mixture containing from 0.5 to 1.5% phosphorus; pressing said blended mixture; and sintering said mixture in a non-oxidizing atmosphere of dry hydrogen at a temperature and for a period of time sufficient to produce a density of at least 7 grams per cubic centimeter, said sintering temperature being at least 2200° F; said soft magnetic material being characterized by a magnetizing force to reach 10 kilogauss of no more than 2.0 oersteds, and a coercive force from 10 kilogauss of no more than 0.9 oersted.
Claim 2
Dependent Claim
142 words
A process for producing a phosphorus containing iron soft magnetic material consisting essentially of iron up to 0.05% carbon, up to 1.0% manganese, up to 0.05% sulfur, up to 0.5% silicon, and from 0.5 to 1.5% phosphorus, which comprises the steps of: blending iron powder and ferro phosphorus powder containing from 22 to 30% phosphorus into a mixture containing from 0.5 to 1.5% phosphorus; pressing said blended mixture; and sintering said mixture in a non-oxidizing atmosphere of dry hydrogen at a temperature and for a period of time sufficient to produce a density of at least 7 grams per cubic centimeter, said sintering temperature being at least 2200° F; said soft magnetic material being characterized by a magnetizing force to reach 10 kilogauss of no more than 2.0 oersteds, and a coercive force from 10 kilogauss of no more than 0.9 oersted.
Claim 3
Dependent Claim
15 words
A process according to claim 1, wherein said sintering temperature is at least 2250° F.
Claim 4
Dependent Claim
40 words
A process according to claim 1, wherein said soft magnetic material is characterized by a magnetizing force to reach 10 kilogauss of no more than 1.75 oersteds, and a coercive force from 10 kilogauss of no more than 0.8 oersted.
Claim 5
Dependent Claim
34 words
A process according to claim 1, wherein said mixture is sintered at a temperature and for a period of time sufficient to produce a density of from 7.15 to 7.35 grams per cubic centimeter.
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) | 1980-09-12 | 1981-03-14 | 1981-09-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-09-12 | 1985-03-14 | 1985-09-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-09-12 | 1989-03-14 | 1989-09-13 | $7700.00 | Window Closed / Lapsed |