A magnetic material is expressed by a composition formula 1: (R.sub.1-xY.sub.x).sub.aM.sub.bT.sub.cZn.sub.d. R is at least one element selected from the group consisting of rare-earth elements, M is Fe or Fe and Co, T is at least one element selected from the group consisting of Ti, V, Nb, Ta, Mo, and W, x is a number satisfying 0.01x0.8, a is a number satisfying 4a20 atomic percent, b is a number satisfying b=100acd atomic percent, c is a number satisfying 0<c<7 atomic percent, and d is a number satisfying 0.01d7 atomic percent. The magnetic material includes: a main phase having a ThMn.sub.12 crystal phase; and a sub phase containing 50 atomic percent or more of Zn.

When a powder material (5) is molded by introducing the material into a cavity (11) between a lower punch (2) and a die (1), compression molding the material between upper and lower punches (3 and 2) into a compact (51) of desired shape, and moving up the lower punch (2) to eject the compact (51), a lubricant is applied to the interior surface of the die (1) by fitting a pad (24) around the lower punch (2) and impregnating the pad with the lubricant. Since the lubricant is applied on every molding operation, molding operation can be continuously carried out.

A rare-earth sintered magnet contains main phase crystal grains having an Nd5Fe17-type crystal structure, includes R and T (where R represents one or more rare-earth elements that essentially include Sm and T represents Fe or one or more transition metal elements that essentially include Fe and Co), and wherein the compositional ratio of R is 20-40 at % and the remaining portion is substantially T; the remaining portion other than R is substantially only T or only T and C; and when the main phase crystal grains' average grain size in one cross-sectional surface of the rare-earth sintered magnet is defined as Dv, while grain size of individual main phase crystal grains is defined as Di, Dv is at least 1.0 m, and the main phase crystal grains' area ratio that satisfy 0.7DvDi2.0Dv is at least 80% with respect to the area of a cross-sectional surface of the rare-earth sintered magnet.

The invention provides an RFeB sintered magnet consisting essentially of 12-17 at % of Nd, Pr and R, 0.1-3 at % of M.sub.1, 0.05-0.5 at % of M.sub.2, 4.8+2*m to 5.9+2*m at % of B, and the balance of Fe, containing R.sub.2(Fe,(Co)).sub.14B intermetallic compound as a main phase, and having a core/shell structure that the main phase is covered with a grain boundary phases. The sintered magnet has an average grain size of less than 6 m, a crystal orientation of more than 98%, and a degree of magnetization of more than 96%, and exhibits a coercivity of at least 10 kOe despite a low or nil content of Dy, Tb, and Ho.

The present invention provides a permeating treatment method for radially oriented sintered magnet, a magnet, and a composition for magnet permeation, wherein in permeating treatment, the magnet and a target permeation source maintain relative movement therebetween all the time, thus internal defects of the oriented sintered magnet are overcome, and the coercivity and thermal stability of the sintered oriented magnet can be stably improved. Moreover, the present invention, having a controllable permeation amount and uniform permeation, is suitable for permeation reaction of a target permeation source with high viscosity or a low melting point, has a wide range of choice for raw materials, and high utilization ratio of permeation elements substantially with no loss, and low cost, thus being suitable for industrialized popularization and use.

An R-T-B-based permanent magnet including: R (rare earth element); T (Fe and Co); B (boron); and one or more selected from Al, Cu, Ga, and Zr. R includes Ce. The total R content is 31.3-34.0 mass % (inclusive), the Co content is 1.85-3.00 mass % (inclusive), the B content is 0.80-0.90 mass % (inclusive), the Al content is 0.03-0.90 mass % (inclusive), the Cu content is 0-0.25 mass % (inclusive), the Ga content is 0-0.10 mass % (inclusive), the Zr content is 0-0.60 mass % (inclusive), and the Fe content is substantially the remainder. The Ce content relative to R is 15-25 mass % (inclusive).

The present invention provides a permeating treatment method for radially oriented sintered magnet, a magnet, and a composition for magnet permeation, wherein in permeating treatment, the magnet and a target permeation source maintain relative movement therebetween all the time, thus internal defects of the oriented sintered magnet are overcome, and the coercivity and thermal stability of the sintered oriented magnet can be stably improved. Moreover, the present invention, having a controllable permeation amount and uniform permeation, is suitable for permeation reaction of a target permeation source with high viscosity or a low melting point, has a wide range of choice for raw materials, and high utilization ratio of permeation elements substantially with no loss, and low cost, thus being suitable for industrialized popularization and use.

A sintered R1-T-B based magnet work and an R2-Ga alloy are provided. The sintered magnet work contains R: 27.5 to 35.0 mass %, B: 0.80 to 0.99 mass %, Ga: 0 to 0.8 mass %, M: 0 to 2 mass % (where M is at least one of Cu, Al, Nb and Zr), and T: 60 mass % or more. A diffusion step of, while keeping at least a portion of the R2-Ga alloy in contact with at least a portion of a surface of the sintered magnet work, performing a first heat treatment at a temperature which is not lower than 700 C. and not higher than 950 C. to increase the RH amount contained in the sintered magnet work by not less than 0.05 mass % and not more than 0.40 mass %, is performed; and a second heat treatment is performed at a temperature which is not lower than 450 C. and not higher than 750 C. but which is lower than the temperature of the first heat treatment.

A method for recycling a rare earth element-containing powder, including: disintegrating a molded body for a rare earth sintered magnet including a rare earth element-containing powder in oil such that a 149 mesh-pass, 500 mesh-on powder is included; and separating and collecting a 149 mesh-pass powder obtained after the disintegrating to obtain a recycles powder.

A permanent magnet of the embodiment includes: a composition represented by a composition formula: R(Fe.sub.pM.sub.qCu.sub.rC.sub.tCo.sub.1-p-q-r-t).sub.z (R is at least one element selected from rare-earth elements, M is at least one element selected from Ti, Zr and Hf, 0.27p0.45, 0.01q0.05, 0.01r0.1, 0.002t0.03, and 6z9); and a metallic structure including a main phase containing a Th.sub.2Zn.sub.17 crystal phase, and a sub phase of the element M having an element M concentration of 30 atomic % or more. The sub phase of the element M precipitates in the metallic structure. A ratio of a circumferential length to a precipitated area of the sub phase of the element M is 1 or more and 10 or less.