Method for preparing permanent magnet material

Details Method for preparing permanent magnet material Method for preparing permanent magnet material

2011-04-12

2011-04-12

Sheehan, John P (Department: 1793)

Metal treatment

Process of modifying or maintaining internal physical...

Magnetic materials

C148S101000, C148S302000

Reexamination Certificate

active

07922832

ABSTRACT:
A permanent magnet material is prepared by machining an anisotropic sintered magnet body having the compositional formula: Rx(Fe1-yCoy)100-x-z-aBzMawherein R is Sc, Y or a rare earth element, M is Al, Cu or the like, to a specific surface area of at least 6 mm−1, heat treating in a hydrogen gas-containing atmosphere at 600-1,100° C. for inducing disproportionation reaction on the R2Fe14B compound, and continuing heat treatment at a reduced hydrogen gas partial pressure and 600-1,100° C. for inducing recombination reaction to the R2Fe14B compound, thereby finely dividing the R2Fe14B compound phase to a crystal grain size ≦1 μm.

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