CPC H01F 7/021 (2013.01) [H01F 1/0533 (2013.01); H01F 41/026 (2013.01)] | 20 Claims |
1. A rare earth magnet material having a roughened structure on a surface,
wherein the surface having the roughened structure comprises a plurality of protrusion regions formed in a length direction and a plurality of recess regions formed in the same direction as the length direction, and the protrusion regions and the recess region are alternately formed in a direction orthogonal to the length direction at the same or different intervals,
wherein the intervals between widthwise center positions of the plurality of protrusion regions or the intervals between widthwise center positions of the plurality of recess regions are in a range from 0.03 to 1.0 mm, and
wherein recesses and protrusions satisfying at least one of the following requirements (a) to (c) are formed in the surface having the roughened structure:
(a) an arithmetic mean height (Sa) (ISO 25178) from 5 to 300 μm,
(b) a maximum height (Sz) (ISO 25178) from 50 to 1500 μm, and
(c) a developed interfacial area ratio (Sdr) (ISO 25178) from 0.3 to 12.
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