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US5049203A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making rare earth magnets

Assignee: Nippon Steel Corp
•
Filing: 1990-04-27
•
Granted: 1991-09-17
•
Expires: 2010-04-27
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Abstract

Abstract A powder X formed by quenching a molten alloy containing, on an atomic percent basis, at least 8%, but less than 13%, of a rare earth component consisting mainly of one or both of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition being iron and unavoidable impurities, and a powder Y formed by quenching a molten alloy containing, on an atomic percent basis, 13 to 20% of a rare earth component consisting mainly of one or both of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition being iron and unavoidable impurities, are mixed to prepare a mixture containing 5 to 50% by volume of powder Y. The mixture is subjected to heat and pressure to make a rare earth magnet containing, on an atomic percent basis, 9 to 14% of a rare earth component consisting mainly of one or both of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition being iron and unavoidable impurities.

Inventors

  • 👤 Toshio Mukai
  • 👤 Tatsuo Fujimoto
  • 👤 Hiroaki Sakamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 04:11
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/057; H01F1/0571; H01F1/0575; H01F1/0576

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 197 words
A method of making a rare earth magnet containing, on an atomic percent basis, 9 to 14% of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, which comprises: mixing a powder X formed by quenching a molten alloy containing, on an atomic percent basis, at least 8% but less than 13%, of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, and a powder Y formed by quenching a molten alloy containing, on an atomic percent basis, 13 to 20% of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, to prepare a mixture containing 5 to 50% by volume of said powder Y; and pressing said mixture at a temperature of 550° C. to 850° C. under a pressure of 0.1 to 5 tons/cm 2 .
Claim 2
Independent Claim 197 words
A method of making a rare earth magnet containing, on an atomic percent basis, 9 to 14% of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, which comprises: mixing a powder X formed by quenching a molten alloy containing, on an atomic percent basis, at least 8% but less than 13%, of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, and a powder Y formed by quenching a molten alloy containing, on an atomic percent basis, 13 to 20% of a rare earth component consisting mainly of at least one of neodymium and praseodymium, and 4 to 8% of boron, the balance of its composition consisting essentially of iron and unavoidable impurities, to prepare a mixture containing 5 to 50% by volume of said powder Y; and pressing said mixture at a temperature of 550° C. to 850° C. under a pressure of 0.1 to 5 tons/cm 2 .
Claim 3
Dependent Claim 28 words
A method as set forth in claim 1, wherein said mixture further contains cobalt in such a proportion as to replace not more than 20% of said iron.
Claim 4
Dependent Claim 20 words
A method as set forth in claim 2, wherein said temperature of 550° C. to 850° C. is electrically supplied.
Claim 5
Dependent Claim 20 words
A method as set forth in claim 1, wherein said temperature of 550° C. to 850° C. is electrically supplied.
Claim 6
Dependent Claim 28 words
A method as set forth in claim 1, wherein each of said powders X and Y has a particle diameter of from about 100 microns to 150 microns.

References Cited (Backward Citations)

JPS6181607A Cited
JPS6181603A Cited
JPS62102504A Cited
US4898625A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-09-16 1995-03-18 1995-09-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-09-16 1999-03-18 1999-09-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-09-16 2003-03-18 2003-09-17 $7700.00 Window Closed / Lapsed

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