US 11,810,713 B2
Rare earth magnet precursor or rare earth magnet molded body having roughened structure on surface and method for manufacturing same
Kiyoshi Shimizu, Tokyo (JP); Masahiko Itakura, Tokyo (JP); Norihisa Wada, Tokyo (JP); and Takayuki Uno, Tokyo (JP)
Assigned to DAICEL MIRAIZU LTD., Tokyo (JP)
Appl. No. 17/299,117
Filed by Daicel Miraizu Ltd., Tokyo (JP)
PCT Filed Dec. 24, 2019, PCT No. PCT/JP2019/050648
§ 371(c)(1), (2) Date Jun. 2, 2021,
PCT Pub. No. WO2020/138094, PCT Pub. Date Jul. 2, 2020.
Claims priority of application No. 2018-240930 (JP), filed on Dec. 25, 2018; application No. 2019-123603 (JP), filed on Jul. 2, 2019; and application No. 2019-216539 (JP), filed on Nov. 29, 2019.
Prior Publication US 2022/0084746 A1, Mar. 17, 2022
Int. Cl. H01F 7/02 (2006.01); H01F 1/053 (2006.01); H01F 41/02 (2006.01)
CPC H01F 7/021 (2013.01) [H01F 1/0533 (2013.01); H01F 41/026 (2013.01)] 20 Claims
OG exemplary drawing
 
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.