Abstract: A single phase consisting of a ThMn12 phase can be obtained by having the composition thereof represented by a general formula R(Fe100-y-wCowTiy)xSizAv (in the general formula, R is at least one element selected from rare earth elements (here the rare earth elements signify a concept inclusive of Y), Nd accounts for 50 mol % or more of R, and A is N and/or C) in which the molar ratios in the general formula are such that x=10 to 12.5, y=(8.3?1.7×z) to 12.3, z=0.1 to 2.3, v=0.1 to 3 and w=0 to 30, and the relation (Fe+Co+Ti+Si)/R>12 is satisfied.

Abstract: A sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the main phase, wherein a platy or acicular product exists. This sintered body enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to improve a suitable sintering temperature range.

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, provided that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe. This sintered body has a coefficient of variation (CV value) showing the dispersion degree of Zr of 130 or less. In addition, this sintered body has a grain boundary phase comprising a region that is rich both in at least one element selected from a group consisting of Cu, Co and R, and in Zr. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: When an R-T-B system rare earth permanent magnet is obtained by a mixing method to obtain a sintered body with a composition consisting essentially of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower, Zr is contained in a low R alloy. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: A method for manufacturing an R-T-B system rare earth permanent magnet that is a sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase, the above manufacturing method comprising the steps of: preparing an R-T-B alloy containing as a main component the R2T14B phase and also containing Zr, and an R-T alloy containing R and T as main components, wherein the amount of R is higher than that of the above R-T-B alloy; obtaining a mixture of the R-T-B alloy powder and the R-T alloy powder; preparing a compacted body with a certain form from the above mixture; and sintering the above compacted body, wherein, in the above sintering step, the above produ

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: A single phase consisting of a ThMn12 phase can be obtained by having the composition thereof represented by a general formula R(Fe100-y-wCowTiy)xSizAv (in the general formula, R is at least one element selected from rare earth elements (here the rare earth elements signify a concept inclusive of Y), Nd accounts for 50 mol % or more of R, and A is N and/or C) in which the molar ratios in the general formula are such that x=10 to 12.5, y=(8.3?1.7×z) to 12.3, z=0.1 to 2.3, v=0.1 to 3 and w=0 to 30, and the relation (Fe+Co+Ti+Si)/R>12 is satisfied.

Abstract: A rare earth permanent magnet consists of 20-40 wt % of at least one rare earth element R, 0.5-4.5 wt % of boron B, 0.03-0.5 wt % of M (at least one of Al, Cu, Sn and Ga), 0.01-0.2 wt % of Bi, and the balance being at least one transition metal element T.

Abstract: An R—T—B system rare earth permanent magnet, which is a sintered body comprising: a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co); and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase. The product that is rich in Zr has a platy or acicular form. The R—T—B system rare earth permanent magnet containing the product enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to obtain a wide suitable sintering temperature range.

Abstract: An R-T-B system rare earth permanent magnet, which is a sintered body comprising: a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co); and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase. The product that is rich in Zr has a platy or acicular form. The R-T-B system rare earth permanent magnet containing the product enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to obtain a wide suitable sintering temperature range.

Abstract: A method for manufacturing an R—T—B system rare earth permanent magnet that is a sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the above main phase, wherein a product that is rich in Zr exists in the above R2T14B phase, the above manufacturing method comprising the steps of: preparing an R—T—B alloy containing as a main component the R2T14B phase and also containing Zr, and an R-T alloy containing R and T as main components, wherein the amount of R is higher than that of the above R—T—B alloy; obtaining a mixture of the R—T—B alloy powder and the R-T alloy powder; preparing a compacted body with a certain form from the above mixture; and sintering the above compacted body, where

Abstract: A sintered body comprising a main phase consisting of an R2T14B phase (wherein R represents one or more rare earth elements (providing that the rare earth elements include Y), and T represents one or more transition metal elements essentially containing Fe, or Fe and Co), and a grain boundary phase containing a higher amount of R than the main phase, wherein a platy or acicular product exists. This sintered body enables to inhibit the grain growth, while keeping a decrease in magnetic properties to a minimum, and to improve a suitable sintering temperature range.

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, provided that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe. This sintered body has a coefficient of variation (CV value) showing the dispersion degree of Zr of 130 or less. In addition, this sintered body has a grain boundary phase comprising a region that is rich both in at least one element selected from a group consisting of Cu, Co and R, and in Zr. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: When an R-T-B system rare earth permanent magnet is obtained by a mixing method to obtain a sintered body with a composition consisting essentially of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower, Zr is contained in a low R alloy. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: A sintered body with a composition consisting of 25% to 35% by weight of R (wherein R represents one or more rare earth elements, providing that the rare earth elements include Y), 0.5% to 4.5% by weight of B, 0.02% to 0.6% by weight of Al and/or Cu, 0.03% to 0.25% by weight of Zr, 4% or less by weight (excluding 0) of Co, and the balance substantially being Fe, wherein a coefficient of variation (CV) showing the dispersion of Zr is 130 or lower. This sintered body enables to inhibit the grain growth, while keeping the decrease of magnetic properties to a minimum, and to improve the suitable sintering temperature range.

Abstract: A rare earth permanent magnet consists of 20-40 wt % of at least one rare earth element R, 0.5-4.5 wt % of boron B, 0.03-0.5 wt % of M (at least one of Al, Cu, Sn and Ga), 0.01-0.2 wt % of Bi, and the balance being at least one transition metal element T.

Abstract: A permanent magnet material is prepared by cooling with a chill roll a molten alloy containing R wherein R is at least one rare earth element inclusive of Y, Fe or Fe and Co, and B. The chill roll has a plurality of circumferentially extending grooves in a circumferential surface, the distance between two adjacent ones of the grooves at least in a region with which the molten alloy comes in contact being 100 to 300 .mu.m on average in an arbitrary cross section containing a roll axis. Permanent magnet material of stable performance is obtained since the variation of cooling rate caused by a change in the circumferential speed of the chill roll is small. The variation of cooling rate is small even when it is desired to change the thickness of the magnet by altering the circumferential speed. The equalized groove pitch results in a minimized variation in crystal grain diameter.

Abstract: An object of the invention is to provide an inexpensive magnet having a high coercivity, high squareness ratio and high maximum energy product. According to the invention, a magnet containing R, T, N, and M wherein R is at least one rare earth element with essential samarium, T is iron or iron and cobalt, and M is at least one element of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C, and P, with essential zirconium, in amounts of 4-8 at % of R, 10-20 at % of N, 2-10 at % of M, and having a hard magnetic phase (TbCu.sub.7 type crystalline phase) and a soft magnetic phase (which is a bcc structured T phase, has an average grain diameter of 5-60 nm, and accounts for 10 to 60% by volume of the entirety), the atomic ratio (R+M)/(R+T+M) in the hard magnetic phase being in excess of 12.5%, is prepared utilizing a single roll technique. In the single roll technique, the peripheral speed of a chill roll is at least 50 m/s, and the discharge pressure of the molten alloy is 0.3-2 kgf/cm.sup.2.

Abstract: In the manufacture of a rare earth sintered magnet of the Nd.sub.2 Fe.sub.14 B system, closed voids are formed in the magnet in a predetermined fraction to minimize shrinkage. Unlike open voids or pores in conventional semi-sintered magnets, the closed voids do not incur magnet corrosion since they do not communicate to the magnet exterior. By minimizing shrinkage during sintering in this way, a ring or plate-shaped thin wall anisotropic magnet can be prepared without machining for shape correction, achieving a cost reduction and a productivity improvement. Since a high density compact has a high deflective strength, it is easy to handle, minimizing cracking and chipping between the compacting and sintering steps.

Abstract: A magnet consists essentially of 4-8 at % of R, 10-20 at % of N, 2-10 at % of M, and the balance of T wherein R is at least one rare earth element, Sm being present in R in a proportion of at least 50 at %, T is Fe or Fe and Co, M is Zr with or without partial replacement by at least one element of Ti, V, Cr, Nb, Hf, Ta, Mo, W, Al, C, and P. Contained in the magnet are a hard magnetic phase based on R, T, and N and containing at least one crystalline phase selected from TbCu.sub.7, Th.sub.2 Zn.sub.17, and Th.sub.2 Ni.sub.17 types and a soft magnetic phase consisting of a T phase having a bcc structure, the soft magnetic phase having a mean grain size of 5-60 nm and being present in a proportion of 10-60% by volume. This construction ensures high coercivity, high squareness ratio, and high maximum energy product.