US4003767A
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Procedure for the production of permanent magnetic sinter bodies using a ternary cobalt-lanthanoid compound
Assignee: UGIMAG RECOMA SA A CORP OF SWITZERLAND
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Filing: 1975-04-07
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Granted: 1977-01-18
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Expires: 1995-04-07
Abstract
Abstract Permanent magnetic sinter bodies are formed by admixing a first binary alloy of cobalt and a first lanthanoid element, with particles of a second binary alloy of cobalt and a second lanthanoid element and thereafter magnetically aligning and sintering said particulate mixture.
Inventors
- 👤 Kurt Bachmann
- 👤 Emanuel DE Lamotte
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:42
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/0555; H01F1/0557; C; C22; C22C; C22C19/00; C22C19/07
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
218 words
A method for producing a permanent magnetic sinter body which comprises: a. admixing particles of a first binary alloy of cobalt and a first lanthanoid element, Ln.sup.(1), having the formula Co 5 Ln.sup.(1) with particles of a second binary alloy of cobalt and a second lanthanoid element, Ln.sup.(2), having the formula Co 5 Ln.sup.(2), b. admixing a different cobalt-samarium alloy with said first and said second binary alloys of cobalt as a sintering additive, c. and thereafter sintering at a temperature 800° - 1350° C, said particulate mixture, whereby a permanent magnet is formed, wherein said lanthanoid elements Ln.sup.(1) and Ln.sup.(2) are different from one another and are selected from the group consisting of yttrium, lanthanum and lanthanoid having an atomic number of 58 to 71; wherein the ratios of the binary alloys are selected so that the proportion of the elements in said sintered body correspond to the formula Co u Ln x .sup.(1) Ln 1 -x .sup.(2), wherein 3.5< u< 5 and 0< x< 1; said cobalt-samarium alloy being composed of 46-65% by weight samarium and 54-35% by weight of cobalt based on the total weight of the alloy, and wherein the weight ratio of said sintering additive is chosen such that the total content of the cobalt in the final mixture is 62-64 wt. percent.
Claim 2
Independent Claim
218 words
A method for producing a permanent magnetic sinter body which comprises: a. admixing particles of a first binary alloy of cobalt and a first lanthanoid element, Ln.sup.(1), having the formula Co 5 Ln.sup.(1) with particles of a second binary alloy of cobalt and a second lanthanoid element, Ln.sup.(2), having the formula Co 5 Ln.sup.(2), b. admixing a different cobalt-samarium alloy with said first and said second binary alloys of cobalt as a sintering additive, c. and thereafter sintering at a temperature 800° - 1350° C, said particulate mixture, whereby a permanent magnet is formed, wherein said lanthanoid elements Ln.sup.(1) and Ln.sup.(2) are different from one another and are selected from the group consisting of yttrium, lanthanum and lanthanoid having an atomic number of 58 to 71; wherein the ratios of the binary alloys are selected so that the proportion of the elements in said sintered body correspond to the formula Co u Ln x .sup.(1) Ln 1 -x .sup.(2), wherein 3.5< u< 5 and 0< x< 1; said cobalt-samarium alloy being composed of 46-65% by weight samarium and 54-35% by weight of cobalt based on the total weight of the alloy, and wherein the weight ratio of said sintering additive is chosen such that the total content of the cobalt in the final mixture is 62-64 wt. percent.
Claim 3
Dependent Claim
66 words
The process of claim 1, wherein the metallurgically smelted binary alloys comprise of SmCo 5 , MMCo 5 and SmCo, wherein the weight ratio of Sm/Co is 60/40 and wherein said alloys are coarsely comminuted to grain sizes of about 1 mm, mixed in a weight ratio of 50:50:14, and then finely comminuted to a grain size of from 1 to 10μ, aligned, pressed and sintered.
Claim 4
Dependent Claim
66 words
The process of claim 1, wherein metallurgically smelted binary alloys comprise SmCo 5 , CeCo 5 , and SmCo, wherein the weight of Sm/Co is 60/40 and wherein said alloys are coarsely comminuted to a grain size of about 1 mm, mixed in a weight ratio of 80:20:14 and then finely comminuted to a grain size of about 1 to 10 μ, aligned, pressed and sintered.
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) | 1980-01-18 | 1980-07-19 | 1981-01-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-18 | 1984-07-19 | 1985-01-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-18 | 1988-07-19 | 1989-01-18 | $7700.00 | Window Closed / Lapsed |