The present disclosure discloses a method for coating a magnetic powder core with sodium silicate, including: using polyoxyethylene laurylether phosphate as a dispersant for sodium silicate and lignosulfonate as a dispersant for a metal magnetic powder, mixing a dispersed sodium silicate solution and a dispersed metal magnetic powder, coating the dispersed metal magnetic powder, and drying: adding an insulating adhesive and a lubricant, subjecting the resulting mixture to a compression molding, and finally, carrying out a high-temperature annealing treatment to obtain a sodium silicate coated magnetic powder core.

The present disclosure discloses a method for coating a magnetic powder core with sodium silicate, including: using polyoxyethylene laurylether phosphate as a dispersant for sodium silicate and lignosulfonate as a dispersant for a metal magnetic powder, mixing a dispersed sodium silicate solution and a dispersed metal magnetic powder, coating the dispersed metal magnetic powder, and drying: adding an insulating adhesive and a lubricant, subjecting the resulting mixture to a compression molding, and finally, carrying out a high-temperature annealing treatment to obtain a sodium silicate coated magnetic powder core.

The present invention provides a rare earth sintered magnet which contains R (R represents one or more rare earth elements essentially including Nd), T (T represents one or more iron group elements essentially including Fe), B, M.sup.1 (M.sup.1 represents one or more elements selected from among Al, Si, Cr, Mn, Cu, Zn, Ga, Ge, Mo, Sn, W, Pb and Bi) and M.sup.2 (M.sup.2 represents one or more elements selected from among Ti, V, Zr, Nb, Hf and Ta), while comprising an R.sub.2T.sub.14B phase as the main phase. This rare earth sintered magnet is characterized in that: the M.sup.1 is in an amount of from 0.5% by atom to 2% by atom; if (R), (T), (M.sup.2) and (B) are the respective atomic percentages of the above-described R, T, M.sup.2 and B, the relational expression (1) ((T)/14)+(M.sup.2)≤(B)≤((R)/2)+((M.sup.2)/2) is satisfied; and from 0.1% by volume to 10% by volume of all grain boundary phases in the magnet is composed of an R.sub.6T.sub.13M.sup.1 phase. This rare earth sintered magnet is able to achieve excellent magnetic characteristics including a good balance between high Br and high H.sub.cJ.

An iron-based rare earth boron-based isotropic magnet alloy, which has an alloy composition represented by T.sub.100-x-y-z(B.sub.1-nC.sub.n).sub.xRE.sub.yM.sub.z (where T is a transition metal element containing at least Fe, RE contains at least Nd, and M is one or more metal elements selected from the group consisting of Al, Si, V, Cr, Ti, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au, and Pb), 4.2 atom %≤x≤5.6 atom %, 11.5 atom %≤y≤13.0 atom %, 0.0 atom %≤z≤5.0 atom %, and 0.0≤n≤0.5, and the iron-based rare earth boron-based isotropic magnet alloy has an average crystal grain size of 10 nm to less than 70 nm as a main phase.

The present invention relates to an alloy with formula of RE-M-B—Fe as defined herein and oxygen content less than 0.9 wt %, wherein said RE is in the range of 29.0 weight % to 33.0 weight %; M is in the range of 0.25 weight % to 1.0 weight %; B is in the range of 0.8 weight % to 1.1 weight %; and Fe makes up the balance. The present invention also relates to a method for preparing a RE-M-Fe—B magnetic powder, as defined herein comprising the steps of: (a) melt spinning a RE-M-Fe—B alloy composition to obtain a melt-spun powder; (b) pressing the melt-spun powder of step (a) to obtain a compact body; (c) hot deforming the compact body of step (b) to obtain a die-upset magnet; (d) crushing the die-upset magnet of step (c) to obtain a powder; (e) milling and sieving the powder of step (d); and (f) passivating the powder of step (e) to obtain a magnetic powder; wherein: each of steps (d) to (f) is performed under a low oxygen environment and transfer between each of steps (d) to (f) is a sealed transfer; and wherein the oxygen content of the low oxygen environment and during each sealed transfer is below 0.5 weight %.

The present invention relates to an alloy with formula of RE-M-B—Fe as defined herein and oxygen content less than 0.9 wt %, wherein said RE is in the range of 29.0 weight % to 33.0 weight %; M is in the range of 0.25 weight % to 1.0 weight %; B is in the range of 0.8 weight % to 1.1 weight %; and Fe makes up the balance. The present invention also relates to a method for preparing a RE-M-Fe—B magnetic powder, as defined herein comprising the steps of: (a) melt spinning a RE-M-Fe—B alloy composition to obtain a melt-spun powder; (b) pressing the melt-spun powder of step (a) to obtain a compact body; (c) hot deforming the compact body of step (b) to obtain a die-upset magnet; (d) crushing the die-upset magnet of step (c) to obtain a powder; (e) milling and sieving the powder of step (d); and (f) passivating the powder of step (e) to obtain a magnetic powder; wherein: each of steps (d) to (f) is performed under a low oxygen environment and transfer between each of steps (d) to (f) is a sealed transfer; and wherein the oxygen content of the low oxygen environment and during each sealed transfer is below 0.5 weight %.

A permanent magnet alloy according to the present disclosure contains Mn at a content not lower than 41% by atom and not higher than 53% by atom; Al at a content not lower than 46% by atom and not higher than 53% by atom; and Cu at a content not lower than 0.5% by atom and not higher than 10% by atom. The alloy contains a stable phase, having a tetragonal structure, at a ratio not lower than 50%.

A composite magnetic body according to one aspect of the present invention includes a first metal magnetic particle covered with a first resin portion made of a first resin material and a second metal magnetic particle having a smaller particle size than the first metal magnetic particle, where the second metal magnetic particle is bound to the first metal magnetic particle via a second resin portion made of a second resin material and the second resin material has a larger molecular weight than the first resin material.

Provided is an R—Fe—B-based sintered magnet which has a composition comprising R (wherein R represents at least one element selected from rare earth elements, and essentially contains Nd), B, M (wherein M represents at least one element selected from Si, Al, Mn, Ni, Co, Cu, Zn, Ga, Ge, Pd, Ag, Cd, In, Sn, Sb, Pt, Au, Hg, Pb and Bi), X (wherein X represents at least one element selected from Ti, Zr, Hf, Nb, V and Ta) and C, with a remainder comprising Fe, O and unavoidable impurities, and has a main phase comprising R.sub.2Fe.sub.14B and a grain boundary phase comprising an R—C phase having a higher R concentration and a higher C concentration than those in the main phase, the R—Fe—B-based sintered magnet being characterized in that the area ratio of the R—C phase in a cross section of the magnet is more than 0% and 0.5% or less.

The present invention is a stator core having a plurality of laminated electrical steel sheets, in which, among a plurality of teeth (121a to 121p) of the stator core, a width of teeth along a direction in which magnetic characteristics are excellent may be narrower than a width of teeth along a direction in which the magnetic characteristics are poor.