Abstract: An R-T-B based sintered magnet including a plural number of main phase particles having an R2T14B type crystal structure. R is at least one rare earth element essentially including heavy rare earth elements RH, T is at least one transition metal element essentially including Fe or Fe and Co, and B is boron. At least one of the main phase particles is a reverse core-shell main phase particle including a core part and a shell part, in which CRC/CRS>1.0 is satisfied when a total RH concentration (at %) in the core part is defined as CRC and a total RH concentration (at %) in the shell part is defined as CRS. An existence ratio of the reverse core-shell main phase particles is larger in a surface layer part of the magnet than in a central part of the magnet.

Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.

Abstract: An R-T-B based sintered magnet including main phase particles having an R2T14B type crystal structure. R is at least one rare earth element essentially including a heavy rare-earth element RH. T is at least one transition metal element essentially including Fe or Fe and Co. B is boron. At least one of the main phase particles includes low RH crystal phases inside the main phase particle. The low RH crystal phases include the R2T14B type crystal structure, wherein an RH concentration in the low RH crystal phases is relatively lower than the RH concentration in the whole main phase particles. The R-T-B based sintered magnet may satisfy rs?rc?20% when an existence ratio of the main phase particles including the low RH crystal phases in a magnet surface layer part is rs (%) and the same in a magnet central part is rc (%).

Abstract: An R-T-B based sintered magnet includes “R”, “T”, and “B”. “R” represents a rare earth element including at least Tb. “T” represents a metal element except rare earth elements including at least Fe, Cu, Mn, Al, and Co. “B” represents boron or boron and carbon. With respect to 100 mass % of a total mass of the R-T-B based sintered magnet, a content of “R” is 28.0 to 32.0 mass %, a content of Cu is 0.04 to 0.50 mass %, a content of Mn is 0.02 to 0.10 mass %, a content of Al is 0.15 to 0.30 mass %, a content of Co is 0.50 to 3.0 mass %, and a content of “B” is 0.85 to 1.0 mass %. Tb2/Tb1 is 0.40 to less than 1.0, where Tb1 and Tb2 (mass %) denote a content of Tb at a surface portion and at a core portion, respectively.

Abstract: A magnetic body constituted by magnetic grains bonded together via oxide film, which magnetic grains contain a Fe—Si-M soft magnetic alloy (where M is a metal element more easily oxidized than Fe) that contains sulfur atoms (S). The magnetic body preferably contains 0.004 to 0.012 percent by weight of S, 1.5 to 7.5 percent by weight of Si, and 2 to 8 percent by weight of metal M.

Abstract: An R-T-B based sintered magnet including a main phase particle comprising an R2T14B type crystal structure. R is at least one rare earth element, T is at least one transition metal element essentially including Fe or Fe and Co, and B is boron. The R-T-B based sintered magnet includes a magnet surface layer part and a magnet central part existing inside the magnet surface layer part. A crystal orientation degree of the main phase particle in the magnet surface layer part having a magnetic pole surface is lower than the crystal orientation degree of the main phase particle in the magnet central part.

Abstract: A rare earth magnet includes main phase grains having an R2T14B type crystal structure. The main phase grains include B. A concentration ratio A (A=?B/?B) of the main phase grains is 1.05 or more, where ?B and ?B are respectively a highest concentration of B and a lowest concentration of B in one main phase grain.

Abstract: An R—Fe—B base sintered magnet is provided comprising a main phase containing an HR rich phase of (R?, HR)2(Fe,(Co))14B wherein R? is an element selected from yttrium and rare earth elements exclusive of Dy, Tb and Ho, and essentially contains Nd, and HR is an element selected from Dy, Tb and Ho, and a grain boundary phase containing a (R?, HR)—Fe(Co)-M1 phase in the form of an amorphous phase and/or nanocrystalline phase, the (R?, HR)—Fe(Co)-M1 phase consisting essentially of 25-35 at % of (R?, HR), 2-8 at % of M1 which is at least one element selected from Si, Al, Mn, Ni, Cu, Zn, Ga, Ge, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Pb, and Bi, up to 8 at % of Co, and the balance of Fe. The HR rich phase has a higher HR content than the HR content of the main phase at its center. The magnet produces a high coercivity despite a low content of Dy, Tb and Ho.

Abstract: A method for manufacturing a rare earth permanent magnet includes manufacturing an NdFeB sintered magnet. A grain boundary diffusion material in the form of a mixed powder comprising an alloy powder containing Re1aMb or M; and Re2 hydride or Re2 fluoride is disposed on a surface of the NdFeB sintered magnet. The grain boundary diffusion material is heated to diffuse at least one of Re1, Re2 and M into a grain boundary part inside the sintered magnet or a grain boundary part region of a sintered magnet main phase grain. Re1 and Re2 are each rare earth elements selected from the group consisting of dysprosium, terbium, neodymium, praseodymium, and holmium, M is a metal compound consisting of copper, zinc, tin, and aluminum, 0.1<a<99.9, and a+b=100.

Abstract: Disclosed herein is a method for manufacturing an R-T-B permanent magnet and the magnet made with the method. The method may include preparation of strip pieces by melting and casting, preparing coarse powder by hydrogen decrepitation of the strip pieces; milling the powder into fine powder; pressing the fine powder is pressed to form a compact, pre-sintering the compact in vacuum or inert gas, machining the pre-sintered block to a desired shape; and dispersing the heavy rare earth compound powder into an organic solvent to prepare a slurry and a second sintering step.

Abstract: A steel plate, the chemical composition of which includes, the contents being expressed by weight: 0.010%?C?0.20%, 0.06%?Mn?3%, Si?1.5%, 0.005%?Al?1.5%, S?0.030%, P?0.040%, 2.5%?Ti?7.2%, (0.45×Ti)?0.35%?B?(0.45×Ti)+0.70%, and optionally one or more elements chosen from: Ni?1%, Mo?1%, Cr?31, Nb?0.1%, V?0.1%, the balance of the composition consisting of iron and inevitable impurities resulting from the smelting.

Abstract: Disclosed are an MnBi sintered magnet exhibiting excellent thermal stability as well as excellent magnetic characteristics at high temperature, an MnBi anisotropic complex sintered magnet, and a method of preparing the same.

Abstract: A process for producing a spring or torsion bar from a steel wire by hot forming may involve providing a steel wire; thermomechanically forming the steel wire; cooling the steel wire thermomechanically; cutting the steel wire to length to give rods; heating the rods; hot forming the rods; and tempering the rods to give a spring or torsion bar, comprising quenching the rods to give a spring or torsion bar to a first cooling temperature, reheating the spring or torsion bar to a first annealing temperature, and cooling the spring or rod to a second cooling temperature. Further, in some examples, the cooling of the steel wire may be cooled to a temperature below a minimum recrystallization temperature such that at least a partly ferritic-pearlitic structure is established in the steel wire.

Abstract: An R-T-B based permanent magnet includes main phase grains composed of R2T14B type compound. R is a rare earth element. T is iron group element(s) essentially including Fe or Fe and Co. B is boron. The magnet contains at least C, Ga, and M selected from Zr, Ti, and Nb in addition to R, T, and B. B is contained at 0.71 mass % to 0.88 mass %. C is contained at 0.15 mass % to 0.34 mass %. Ga is contained at 0.40 mass % to 1.40 mass %. M is contained at 0.25 mass % to 2.50 mass %. A formula (1) of 0.14?[C]/([B]+[C])?0.30 and a formula (2) of 5.0?[B]+[C]?[M]?5.6 are satisfied, where [B], [C], and [M] are respectively a content of B, C, and M by atom %.

Abstract: An object of the present invention is to provide an R-T-B based permanent magnet showing high residual magnetic flux density Br and coercive force HcJ, and further showing the same also after heavy rare earth element is diffused along grain boundaries. Provided is an R-T-B based permanent magnet in which, R is a rare earth element, T is an element other than the rare earth element, B, C, O or N, and B is boron. T at least includes Fe, Cu, Co and Ga, and a total of R content is 28.0 to 30.2 mass %, Cu content is 0.04 to 0.50 mass %, Co content is 0.5 to 3.0 mass %, Ga content is 0.08 to 0.30 mass %, and B content is 0.85 to 0.95 mass %, relative to 100 mass % of a total mass of R, T and B.

Abstract: An object of the present invention is to provide an R-T-B based permanent magnet showing high residual magnetic flux density Br and coercive force HcJ. Provided is an R-T-B based permanent magnet in which, R is a rare earth element, T is an element other than the rare earth element, B, C, O or N, and B is boron. R at least includes Tb and T at least includes Fe, Cu, Co and Ga, and a total of R content is 28.05 to 30.60 mass %, Cu content is 0.04 to 0.50 mass %, Co content is 0.5 to 3.0 mass %, Ga content is 0.08 to 0.30 mass %, and B content is 0.85 to 0.95 mass %, relative to 100 mass % of a total mass of R, T and B, and Tb concentration reduces from outside to inside of the R-T-B based permanent magnet.

Abstract: A NdFeB magnet containing cerium and a manufacturing method thereof are provided. The manufacturing method includes steps of: refining a part of raw materials pure iron, ferro-boron, and rare earth fluoride in a crucible, adding a rest of the raw materials into the crucible and refining, casting a refined solution to a surface of a water-cooled rotation roller through a tundish and forming alloy flakes, processing the alloy flakes containing at least two different compositions with hydrogen decrepitation, milling powders, magnetic field pressing, vacuum presintering, machining and sintering, and obtaining the NdFeB magnet containing cerium. The NdFeB magnet containing cerium has a density of 7.5-7.7 g/cm3 and an average particle size of 3-7 ?m; comprises a main phase and a grain boundary phase distributed around the main phase. A composite phase containing Tb is provided between the main phase and the grain boundary phase.

Abstract: The invention provides a high-performance permanent magnet. The permanent magnet has a composition that is expressed by a composition formula RpFeqMrCutCo100-p-q-r-t, where R is at least one element selected from a rare earth element, M is at least one element selected from the group consisting of Zr, Ti, and Hf, p is a number satisfying 10.8?p?12.5 atomic percent, q is a number satisfying 25?q?40 atomic percent, r is a number satisfying 0.88?r?4.5 atomic percent, and t is a number satisfying 3.5?t?13.5 atomic percent. The permanent magnet also has a metallic structure that includes a main phase having a Th2Zn17 crystal phase, and a Cu-M rich phase having a higher Cu concentration and a higher M concentration than the main phase.

Abstract: A diffusion treatment device includes: a treatment container including a cylindrical main body and first and second lids, the cylindrical main body having a treatment space which is capable of receiving sintered magnet pieces and RH diffusion sources, the first and second lids being capable of hermetically sealing first and second openings, respectively, at opposite ends of the cylindrical main body; a conveyor for conveying the treatment container by a predetermined distance in an x-axis direction while a longitudinal direction of the treatment container is located in a y-axis direction in a rectangular coordinate system xyz; a heating unit including a lower heating section provided under the treatment container and an upper heating section provided above the treatment container, and a first rotating unit for rotating the treatment container around a y-axis while the longitudinal direction of the treatment container is located in the y-axis direction.

Abstract: Provided is a high-strength seamless steel pipe having the composition which contains, by mass %, 0.20 to 0.50% C, 0.05 to 0.40% Si, 0.3 to 0.9% Mn, 0.015% or less P, 0.005% or less S, 0.005 to 0.1% Al, 0.008% or less N, more than 0.6% and 1.7% or less Cr, more than 1.0% and 3.0% or less Mo, 0.01 to 0.30% V, 0.001% or more and less than 0.01% Nb, 0.0003 to 0.0030% B, and 0.0030% or less O (oxygen). The high-strength seamless steel pipe has the microstructure where a volume fraction of a tempered martensitic phase is 95% or more, and prior austenitic grains have a grain size number of 8.5 or more, and a segregation degree index Ps which is defined by a formula Ps=8.1 (XSi+XMn+XMo)+1.2XP is set to less than 65.