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.
Claims12
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, substantially containing no N and containing 4 at. % or more of B;
- and 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.
A permanent magnetic alloy having a basic composition represented by the formula:
- RxFe100−x−y−z−wCoyMwBz
- wherein R is at least one element selected from rare earth elements including Y;
- M is at least one element selected from the group consisting of Nb, Ti, Zr, Hf, V, Mo, Cr and Mn;
- x, y, z and w are atomic percentages satisfying 4≦x≦11, 0≦y≦30, 4≦z≦11, and 0≦w≦8, and B and R satisfy 0.30≦B/R≦2.5 wherein B/R is an atomic percent ratio of B and R, and comprising a TbCu7 hard magnetic phase as a main phase.
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, substantially containing no N and containing 4 at. % or more of B, and 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.
A bonded magnet comprising a permanent magnetic alloy bonded with a binder, wherein the permanent magnetic alloy comprises a TbCu7 hard magnetic phase as a main phase and has a basic composition represented by the formula:
- RxFe100−x−y−z−wCoyMwBz
- wherein R is at least one element selected from rare earth elements including Y;
- M is at least one element selected from the group consisting of Nb, Ti, Zr, Hf, V, Mo, Cr and Mn;
- x, y, z and w are atomic percentages satisfying 4≦x≦11, 0≦y≦30, 4≦z≦11, and 0≦w≦8;
- and B and R satisfy 0.30≦B/R≦2.5 wherein B/R is an atomic percent ratio of B and R.
Dependencies are inferred from the claim text.