A method of producing a SmFeN-based rare earth magnet, the method including: dispersing a SmFeN-based anisotropic magnetic powder comprising Sm, Fe, and N using a resin-coated metal media or a resin-coated ceramic media to obtain a dispersed SmFeN-based anisotropic magnetic powder; mixing the dispersed SmFeN-based anisotropic magnetic powder with a modifier powder to obtain a powder mixture; compacting the powder mixture in a magnetic field to obtain a magnetic field compact; pressure-sintering the magnetic field compact to obtain a sintered compact; and heat treating the sintered compact.

A method for producing a heavy rare earth grain-boundary-diffused RE-Fe—B-based rare earth magnet and a heavy rare earth grain-boundary-diffused RE-Fe—B-based rare earth magnet produced thereby is disclosed. More particularly, a method for producing a heavy rare earth grain-boundary-diffused RE-Fe—B-based rare earth sintered magnet having a reduced content of a heavy rare earth element is disclosed, in which a hydrogen compound of a heavy rare earth is mainly used as a diffusion material in the production of the grain-boundary-diffused magnet so that a product having uniform and stable quality can be produced. The coercive force of the magnet can be increased while minimizing the amount of heavy rare earth used in the production of the grain-boundary-diffused magnet, by solving the problem that the heavy rare earth is not uniformly diffused into the magnet, and a heavy rare earth grain-boundary-diffused RE-Fe—B-based rare earth magnet produced thereby.

Disclosed is a grain-oriented electrical steel sheet that has excellent high-frequency iron loss properties and blanking workability. The steel sheet includes: steel components including, by mass %, Si: 1.5-8.0%, Mn: 0.02-1.0%, and at least one selected from Sn: 0.010-0.400%, Sb: 0.010-0.400%, Mo: 0.010-0.200%, and P: 0.010-0.200%; and crystal grains including coarse secondary recrystallized grains having an average grain size of 5 mm or more and fine grains having a grain size of 0.1-2.0 mm, wherein at least some of the coarse secondary recrystallized grains penetrate the steel sheet in a thickness direction and are respectively exposed on front and back surfaces of the steel sheet such that projection planes of the exposed surfaces of these coarse secondary recrystallized grains on the front and back surfaces form an overlapping region, and the fine grains are present at a number density per unit area of 0.6-40 pieces/cm.sup.2.

The present invention relates to an RFeB-based sintered magnet having a composition including: 24-31% by mass of at least one element selected from the group consisting of Nd, Pr, La and Ce; 0.1-6.5% by mass of at least one element selected from the group consisting of Dy and Tb; 0.8-1.4% by mass of B; 0.03-0.2% by mass of at least one element selected from the group consisting of Zr, Ti, Hf and Nb; 0.8-5.5% by mass of Co; 0.1-1.0% by mass of Cu; and 0.1-1.0% by mass of Al, with a remainder being Fe and unavoidable impurities, in which the composition has a total content of Cu and Al being higher than 0.5% by mass.

A non-oriented electrical steel sheet with an average magnetostriction λ.sub.p-p at 400 Hz and 1.0 T of not more than 4.5×10.sup.−6, and area ratio of recrystallized grains at a section in rolling direction of steel sheet of 40 to 95% and an average grain size of 10 to 40 μm is obtained by subjecting a steel slab containing, in mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si—2Al—Mn≥0 to hot rolling, hot-band annealing, cold rolling and finish annealing under adequate cold rolling and finish annealing conditions, and a motor core is manufactured by such a steel sheet.

A method of making a component of an electrical machine is provided. An additive manufacturing process is used to manufacture a part, including applying beams of energy to a successive plurality of ferromagnetic material particles and fusing them together to form a ring or segment of a ring with an axis, a solid portion, and laminas that extend from the solid portion in a radial or axial direction.

A method of making a component of an electrical machine is provided. An additive manufacturing process is used to manufacture a part, including applying beams of energy to a successive plurality of ferromagnetic material particles and fusing them together to form a ring or segment of a ring with an axis, a solid portion, and laminas that extend from the solid portion in a radial or axial direction.

A silicon oxide-coated soft magnetic powder, in which the ratio of a volume-based cumulative 50% particle diameter D50 (HE) according to a dry laser diffraction particle size distribution analysis to the same particle diameter D50 (MT) according to a wet laser diffraction particle size distribution analysis is 0.7 or more, and a coverage ratio R defined by R=Si×100/(Si+M) (Si and M are molar fractions of Si and elements constituting the soft magnetic powder) is 70% or more is obtained by subjecting a slurry containing a soft magnetic powder containing 20 mass % or more of iron and a hydrolysate of a silicon alkoxide to a dispersion treatment when the surface of the soft magnetic powder is coated with the hydrolysate in a mixed solvent of water and an organic substance. The powder has good insulation/dispersibility properties and a high filling factor during molding.

According to an exemplary embodiment of the present invention, a method for manufacturing a grain-oriented electrical steel sheet includes: a step of hot-rolling a slab to manufacture a hot-rolled steel sheet; a step of performing hot-rolled sheet annealing on the hot-rolled steel sheet; a step of performing primary cold-rolling on the hot-rolled sheet annealed hot-rolled steel sheet; a step of performing primary decarburization annealing on the primarily cold-rolled steel sheet; a step of performing secondary cold-rolling on the decarburization-annealed steel sheet; a step of performing secondary decarburization annealing on the secondarily cold-rolled steel sheet; and a step of performing continuous annealing on the secondarily decarburization-annealed steel sheet.

Provided are a motor core having excellent fatigue resistance and a method of manufacturing the motor core at a low cost. The motor core that is an electrical-steel-sheet-stacked body has an outer peripheral surface in which an appearance ratio of recrystallized grains with a grain size of 15 μm or less is 70% or more of a sheet thickness of the motor core.