Permanent magnetic alloy and bonded magnet
AssigneeHitachi Metals, Ltd.
InventorsMitsuaki Mochizuki, Michihisa Shimizu, Tsunehiro Kawata, Masao Murakawa
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Abstract
The permanent magnetic alloy of the present invention comprises an R—Fe—B alloy wherein R is at least one element selected from rare earth elements including Y. The R—Fe—B alloy has a composition mainly comprising Fe, substantially containing no N, and containing 4 at. % or more of B. The permanent magnetic alloy substantially comprises a TbCu7 hard magnetic phase (main phase) and a fine crystal having an average crystal grain size of less than 5 nm and/or an amorphous phase, and has high magnetic properties.
Claims7
A permanent magnetic alloy comprising an R—Fe—B alloy wherein R is at least one element selected from rare earth elements including Y, the R—Fe—B alloy having a composition mainly comprising Fe, containing N in an amount of more than 0.0001 at. % but 0.01 at. % or less and containing 4 at. % or more of B;
- the R—Fe—B alloy substantially comprising a TbCu7 hard magnetic phase (main phase) and a fine crystal having an average crystal grain size of less than 5 nm and/or an amorphous phase;
- and the R—Fe—B alloy being produced by quenching a hot melt of said R—Fe—B alloy by a cooling roll method at a peripheral speed of the cooling roll within 5 to 28 m/s.
A bonded magnet comprising a permanent magnetic alloy bonded with a binder, wherein the permanent magnetic alloy comprises an R—Fe—B alloy wherein R is at least one element selected from rare earth elements including Y, the R—Fe—B alloy having a composition mainly comprising Fe, containing N in an amount of more than 0.0001 at. % but 0.01 at. % or less and containing 4 at. % or more of B;
- the R—Fe—B alloy substantially comprising a TbCu7 hard magnetic phase (main phase) and a fine crystal having an average crystal grain size of less than 5 nm and/or an amorphous phase;
- and the R—Fe—B alloy being produced by quenching a hot melt of said R—Fe—B alloy by a cooling roll method at a peripheral speed of the cooling roll within 5 to 28 m/s.
Dependencies are inferred from the claim text.