Cast rare earth-containing alloy sheet, manufacturing method therefor, and sintered magnet
AssigneeSantoku Corporation
InventorYasutomo Matsumoto
Life of this patent
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Abstract
Rare earth-containing alloy flakes and a sintered magnet made of the same are provided, which alloy flakes are useful in the production of sintered magnets of which Br and HcJ may be excellent and well-balanced according to the Dy and/or Tb content. The rare earth-containing alloy flakes are R-TM-A-M-type alloy flakes which have a particular composition, and a structure having a Nd2Fe14B main phase and a boundary phase, the Fe content in the boundary phase is not more than 10 mass %, and a ratio of the total content (b) of Dy and Tb in the boundary phase to the total content (a) of Dy and Tb in the main phase is higher than 1.0, and are useful as a sintered magnet material.
Claims8
R-TM-A-M-type rare earth-containing alloy flakes of a composition consisting of:
- not less than 27.0 mass % and not more than 40.0 mass % R representing at least two elements selected from the group consisting of Y, Sc, and lanthanoid elements of atomic numbers 57 to 71, with Nd and at least one of Dy and Tb being essential;
- not less than 0.7 mass % and not more than 2.0 mass % A representing B, or B and C;
- not less than 0 mass % and not more than 3.0 mass % M representing at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Pb, and Bi;
- and
- a balance TM representing Fe, or Fe and Co;
- wherein a content of Dy and Tb in R is not less than 0.1 mass % and not more than 10.0 mass %,
- wherein said alloy flakes have a structure having a Nd2Fe14B main phase and a boundary phase,
- wherein a Fe content in said boundary phase is not more than 10 mass %, and
- wherein a ratio of a total content (b) of Dy and Tb in said boundary phase to a total content (a) of Dy and Tb in said main phase is higher than 1.0.
Dependencies are inferred from the claim text.