US4396441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permanent magnet having ultra-high coercive force and large maximum energy product and method of producing the same
Assignee: Research Institute for Electromagnetic Materials
•
Filing: 1981-11-05
•
Granted: 1983-08-02
•
Expires: 2001-11-05
Abstract
Abstract The disclosed permanent magnet has a coercive force of 500 Oe or more, a residual magnetic flux density of 5 kG or more, and a maximum energy product of 2 MG. Oe or more. The magnet alloy consists essentially of platinum and iron, and has an initial state of homogeneous dispersion of gamma 1 phase of face-centered tetragonal type in a gamma phase matrix of face-centered cubic type. To produce the magnet, the alloy is heated at 900 DEG to 1,400 DEG C. for 1 minute to 100 hours for homogenizing solid solution treatment, and quenched in water or in air at a rate of 30 DEG C./minute to 2,000 DEG C./second.
Inventors
- 👤 Hakaru Masumoto
- 👤 Kiyoshi Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:36
CPC Classifications
H; H01; H01F; H01F7/00; H01F7/02; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F41/00; H01F41/02; H01F41/0253
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A permanent magnet, said permanent magnet having a coercive force of not less than 500 Oe, a residual magnetic flux density of not less than 5 kG, and a maximum energy product of not less than 2 MG.Oe, said permanent magnet consisting of 33.5 to 47.5 atomic % (63.76 to 75.96 weight %) of platinum and the remainder of iron with less than 0.5% of impurities, said permanent magnet having a structure of homogeneous dispersion of γ 1 phase of face-centered tetragonal type in a γ phase matrix of face-centered cubic type.
Claim 2
Dependent Claim
92 words
A permanent magnet, said permanent magnet having a coercive force of not less than 500 Oe, a residual magnetic flux density of not less than 5 kG, and a maximum energy product of not less than 2 MG.Oe, said permanent magnet consisting of 33.5 to 47.5 atomic % (63.76 to 75.96 weight %) of platinum and the remainder of iron with less than 0.5% of impurities, said permanent magnet having a structure of homogeneous dispersion of γ 1 phase of face-centered tetragonal type in a γ phase matrix of face-centered cubic type.
Claim 3
Independent Claim
83 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900° to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, and quenching said alloy in water or in air at a rate of 30° C./minute to 2,000° C./second.
Claim 4
Independent Claim
83 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900° to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, and quenching said alloy in water or in air at a rate of 30° C./minute to 2,000° C./second.
Claim 5
Independent Claim
88 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900 to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, quenching said alloy, reheating said quenched alloy at 400° to 700° C. for one minute to 100 hours, and cooling the reheated alloy.
Claim 6
Independent Claim
88 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900 to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, quenching said alloy, reheating said quenched alloy at 400° to 700° C. for one minute to 100 hours, and cooling the reheated alloy.
Claim 7
Independent Claim
121 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900° to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, quenching said alloy in water or in air at a rate of 30° C./minute to 2,000° C./second, applying plastic working of not less than 90% to the thus quenched alloy by drawing into wire or rolling, reheating the worked alloy at 400° to 700° C. for one minute to 300 hours, and cooling the reheated alloy.
Claim 8
Independent Claim
121 words
A method of producing a permanent magnet having an ultra-high coercive force and a large maximum energy product, comprising steps of heating an alloy at 900° to 1,400° C. for one minute to 100 hours so as to effect homogenizing solid solution treatment, which alloy consists of 33.5 to 47.5 atomic % of platinum and the remainder of iron with a small amount of impurities, quenching said alloy in water or in air at a rate of 30° C./minute to 2,000° C./second, applying plastic working of not less than 90% to the thus quenched alloy by drawing into wire or rolling, reheating the worked alloy at 400° to 700° C. for one minute to 300 hours, and cooling the reheated alloy.
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) | 1986-08-01 | 1987-01-31 | 1987-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-01 | 1991-01-31 | 1991-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-01 | 1995-01-31 | 1995-08-02 | $7700.00 | Window Closed / Lapsed |