Metal treatment – Process of modifying or maintaining internal physical... – Magnetic materials
Reexamination Certificate
2006-02-07
2006-02-07
Sheehan, John P. (Department: 1742)
Metal treatment
Process of modifying or maintaining internal physical...
Magnetic materials
C148S302000, C075S244000, C419S012000
Reexamination Certificate
active
06994755
ABSTRACT:
Disclosed are methods for producing compositionally modified sintered RE—Fe—B-based rare earth permanent magnets, by the addition of small amounts of Nd, Cu, Ti, Nb, or other transition metals, and mixtures thereof, to maximize fracture toughness with corresponding improved machinability, while maintaining maximum energy product, said method comprising the steps of:(a) prepare a magnetic composition;(b) melt the composition and form powders with an average particle size smaller than 5 microns from the same;(c) press the powder under a magnetic field to obtain green compacts, which are then sintered at from about 1030° C. to 1130° C., and heat treating the sintered material at from about 570° C. to 900° C.
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Liu Jinfang
Liu Shiqiang
Dinsmore & Shohl LLP
Electron Energy Corporation
Sheehan John P.
University of Dayton
LandOfFree
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