Provided are molds for polar anisotropic ring-shaped bonded magnet molded articles which enable the production of bonded magnet molded articles with a high degree of roundness and only slight distortion, without the need for mold modification and preparation of a test mold, and a method of preparing such molds. The present invention relates to a method of preparing a mold for a polar anisotropic ring-shaped bonded magnet molded article, the method including: 1) determining the shrinkage length (Tc) of a desired polar anisotropic ring-shaped bonded magnet molded article using the following equation: Tc=T×(α1/100−α2/100); 2) determining the radius (Dm) of a magnetic pole portion of a mold cavity using the following equation: Dm=D/(1−α2/100); and 3) defining the outer peripheral shape of the mold cavity from the Tc, the Dm, and the number (P) of magnetic poles of the molded article.

An anisotropic rare earth sintered magnet represented by the formula (R.sub.1-aZr.sub.a).sub.x(Fe.sub.1-b CO.sub.b).sub.100-x-y(M.sup.1.sub.1-cM.sup.2.sub.c).sub.y where R is at least one element selected from rare earth elements and Sm is essential; M.sup.1 is at least one of V, Cr, Mn, Ni, Cu, Zn, Ga, Al, and Si; M.sup.2 is at least one of Ti, Nb, Mo, Hf, Ta, and W; and x, y, a, b, and c each satisfy certain conditions. The anisotropic rare earth sintered magnet includes 80% by volume or more of a main phase composed of a compound of a ThMn.sub.12 type crystal, the main phase having an average crystal grain size of 1 μm or more, and containing an R-rich phase and an R(Fe,Co).sub.2 phase in a grain boundary portion. A method for producing the anisotropic rare earth sintered magnet is also described.

A samarium-iron-nitrogen based magnet, wherein a samarium oxide phase is formed on at least a part of a surface of a crystal grain, and wherein an atomic ratio of calcium to a total amount of iron group elements, rare earth elements, and calcium is 0.4% or less.

A samarium-iron-nitrogen based magnet, wherein a samarium oxide phase is formed on at least a part of a surface of a crystal grain, and wherein an atomic ratio of calcium to a total amount of iron group elements, rare earth elements, and calcium is 0.4% or less.

The present invention relates to a composite component including a metal component having a substantially cylindrical shape or a substantially annular shape, and a ring-shaped bonded magnet disposed on the outer periphery of the metal component, the ring-shaped bonded magnet containing a thermoplastic resin, magnetic particles, and rubber particles.

The present invention relates to a composite component including a metal component having a substantially cylindrical shape or a substantially annular shape, and a ring-shaped bonded magnet disposed on the outer periphery of the metal component, the ring-shaped bonded magnet containing a thermoplastic resin, magnetic particles, and rubber particles.

A method of producing a phosphate-coated SmFeN-based anisotropic magnetic powder, the method including performing a phosphate treatment including adding an inorganic acid to a slurry containing a raw material SmFeN-based anisotropic magnetic powder, water, a phosphate compound, and a rare earth compound so that the slurry is adjusted to have a pH of at least 1 and not higher than 4.5 to obtain a phosphate-coated SmFeN-based anisotropic magnetic powder having a surface coated with a phosphate.

A method of producing a phosphate-coated SmFeN-based anisotropic magnetic powder, the method including performing a phosphate treatment including adding an inorganic acid to a slurry containing a raw material SmFeN-based anisotropic magnetic powder, water, a phosphate compound, and a rare earth compound so that the slurry is adjusted to have a pH of at least 1 and not higher than 4.5 to obtain a phosphate-coated SmFeN-based anisotropic magnetic powder having a surface coated with a phosphate.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.

Provided are a method of producing a titanium-containing rare earth-iron-nitrogen anisotropic magnetic powder having good magnetic properties, and secondary particles for a titanium-containing anisotropic magnetic powder. The method includes: obtaining a first precipitate containing R, iron, and titanium by mixing a first precipitating agent with a solution containing R, iron, and titanium, wherein R is at least one selected from Sc, Y, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Tm, and Lu; obtaining a second precipitate containing R and iron by mixing, in the presence of the first precipitate, a second precipitating agent with a solution containing R and iron; obtaining an oxide containing R, iron, and titanium by calcining the second precipitate; obtaining a partial oxide by heat treating the oxide in a reducing gas atmosphere; obtaining alloy particles by reducing the partial oxide; and obtaining an anisotropic magnetic powder by nitriding the alloy particles.