Abstract: A sintered R-T-B based magnet composition includes: R: not less than 27 mass % and not more than 37 mass % (R is at least one rare-earth element which always includes at least one of Nd and Pr), B: not less than 0.75 mass % and not more than 0.97 mass %, Ga: not less than 0.1 mass % and not more than 1.0 mass %, Cu: not less than 0 mass % and not more than 1.0 mass %, and T: 61.03 mass % or more (where T is at least one selected from Fe, Co, Al, Mn and Si and always includes Fe, such that the Fe content is 80 mass % or more in the entire T). [T]/[B] is greater than 14.0. An R amount is greater in the surface than in the center, and a Ga amount is greater in the surface than in the center. [T]/[B] in the surface is higher than [T]/[B] in the center.

Abstract: In an embodiment, a sintered R-T-B based magnet according to the present disclosure has a composition as follows: R: not less than 27 mass % and not more than 37 mass % (R is at least one rare-earth element which always includes at least one of Nd and Pr), B: not less than 0.75 mass % and not more than 0.97 mass %, Ga: not less than 0.1 mass % and not more than 1.0 mass %, Cu: not less than 0 mass % and not more than 1.0 mass %, and T: 61.03 mass % or more (where T is at least one selected from the group consisting of Fe, Co, Al, Mn and Si and always includes Fe, such that the Fe content accounts for 80 mass % or more in the entire T). The molar ratio of T to B ([T]/[B]) is greater than 14.0. An R amount in a magnet surface portion is greater than an R amount in a magnet central portion, and a Ga amount in the magnet surface portion is greater than a Ga amount in the magnet central portion.

Abstract: [Problem] There is provided a method of producing a sintered R-T-B based magnet in which even the intergranular grain boundaries in the magnet interior can be made thick, which does not allow coercivity improvement effects to be significantly undermined even after a surface grinding, and which has high coercivity without the use of heavy rare-earth elements. [Solution] It includes: a step of providing an R1-T1-A-X (where R1 is mainly Nd; T1 is mainly Fe; A is at least one of Ga, Ti, Zr, Hf, V, Nb and Mo; and X is mainly B) based sintered alloy compact which is mainly characterized in that a molar ratio of Ti/(X-2A) is not less than 13; a step of providing an R2-Ga—Cu (where R2 is mainly Pr and/or Nd and accounts for 65 mol % and not more than 95 mol %; and Cu/(Ga+Cu) is not less than 0.1 and not more than 0.

Abstract: A step of providing an R1-T1-X (where R1 is mainly Nd; T1 is mainly Fe; and X is mainly B) based sintered alloy compact mainly characterized by a molar ratio of [T1]/[X] being 13.0 or more; a step or providing an R2-Ga—Cu (where R2 is mainly Pr and/or Nd and accounts for not less than 65 mol % and not more than 95 mol %; and [Cu]/([Ga]+[Cu]) is not less than 0.1 and not more than 0.9 by mole ratio) based alloy; and a step of, while allowing at least a portion of a surface of the R1-T1-X based sintered alloy compact to be in contact with at least a portion of the R2-Ga—Cu based alloy, performing a heat treatment at a temperature which is not less than 450° C. and not more than 600° C.

Abstract: A nanocomposite magnet according to the present invention has a composition represented by the general formula: RxQyMz(Fe1-mTm)bal, where R is at least one rare-earth element, Q is at least one element selected from the group consisting of B and C, M is at least one metal element that is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb and that always includes Ti, and T is at least one element selected from the group consisting of Co and Ni. The mole fractions x, y, z and m satisfy the inequalities of 6 at %?x<10 at %, 10 at %?y?17 at %, 0.5 at %?z?6 at % and 0?m?0.5, respectively. The nanocomposite magnet includes a hard magnetic phase and a soft magnetic phase that are magnetically coupled together. The hard magnetic phase is made of an R2Fe14B-type compound, and the soft magnetic phase includes an ?-Fe phase and a crystalline phase with a Curie temperature of 610° C. to 700° C. (? phase) as its main phases.

Abstract: A nanocomposite magnet according to the present invention has a composition represented by the general formula: RxQyMz(Fe1-mTm)bal, where R is at least one rare-earth element, Q is at least one element selected from the group consisting of B and C, M is at least one metal element that is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb and that always includes Ti, and T is at least one element selected from the group consisting of Co and Ni. The mole fractions x, y, z and m satisfy the inequalities of 6 at %?x<10 at %, 10 at %?y?17 at %, 0.5 at %?z?6 at % and 0?m?0.5, respectively. The nanocomposite magnet includes a hard magnetic phase and a soft magnetic phase that are magnetically coupled together. The hard magnetic phase is made of an R2Fe14B-type compound, and the soft magnetic phase includes an ?-Fe phase and a crystalline phase with a Curie temperature of 610° C. to 700° C. (? phase) as its main phases.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x?20 at %; 6 at %?y<10 at %; 0.1 at %?z?12 at %; and 0?m?0.5, respectively.

Abstract: A nanocomposite magnet according to the present invention has a composition represented by the general formula: RxQyMz(Fe1?mTm)bal, where R is at least one rare-earth element, Q is at least one element selected from the group consisting of B and C, M is at least one metal element that is selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb and that always includes Ti, and T is at least one element selected from the group consisting of Co and Ni. The mole fractions x, y, z and m satisfy the inequalities of 6 at % ?x<10 at %, 10 at % ?y?17 at %, 0.5 at % ?z?6 at % and 0?m?0.5, respectively. The nanocomposite magnet includes a hard magnetic phase and a soft magnetic phase that are magnetically coupled together. The hard magnetic phase is made of an R2Fe14B-type compound, and the soft magnetic phase includes an ?-Fe phase and a crystalline phase with a Curie temperature of 610° C. to 700° C. (? phase) as its main phases.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x≦20 at %; 6 at %≦y<10 at %; 0.1 at %≦z≦12 at %; and 0≦m≦0.5, respectively.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x≦20 at %; 6 at %≦y<10 at %; 0.1 at %≦z≦12 at %; and 0≦m≦0.5, respectively.

Abstract: A method of making an iron base magnetic material alloy powder includes the steps of: preparing an iron base magnetic material alloy containing at least 50% by mass of iron; and pulverizing the magnetic material alloy using a pin mill. A portion of the mill, which comes into contact with the magnetic material alloy, is made of a cemented carbide material at least partially.

Abstract: The inventive method for preparing nanocomposite magnet powder includes the step of preparing material alloy powder for a nanocomposite magnet represented by a general formula Fe100−x−y−z−uRxByCozMu where R is a rare-earth element of which 90-100 atomic percent is Pr and/or Nd while 0-10 atomic percent is another lanthanoid and/or Y, and the molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The powder includes a metastable phase and an amorphous structure existing in a metal structure. Heat treatment is performed for the material alloy powder to crystallize Fe3B and Fe—R—B compounds from the amorphous structure. An integral value of the difference between a temperature-time curve represented by the temperature of the material alloy powder as a function of the heat treatment time during the heat treatment and a reference temperature-time curve is in a range from 10° C.

Abstract: An iron-based rare earth alloy magnet has a composition represented by the general formula: (Fe1-mTm)100-x-y-zQxRyMz, where T is at least one element selected from the group consisting of Co and Ni; Q is at least one element selected from the group consisting of B and C; R is at least one rare earth element substantially excluding La and Ce; and M is at least one metal element selected from the group consisting of Ti, Zr and Hf and always includes Ti. In this formula, the mole fractions x, y, z and m meet the inequalities of: 10 at %<x≦20 at %; 6 at %≦y<10 at %; 0.1 at %≦z≦12 at %; and 0≦m≦0.5, respectively.

Abstract: An inventive material alloy for a nanocomposite magnet is represented by a general formula Fe100−x−yRxBy, Fe100−x−y−zRxByCoz, Fe100−x−y−uRxByMu or Fe100−x−y−z−uRxByCozMu. R is a rare-earth element. 90 atomic percent or more of R is Pr and/or Nd, while equal to or larger than 0 atomic percent and less than 10 atomic percent of R is another lanthanoid and/or Y. M is at least one element selected from the group consisting of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Ga, Zr, Nb, Mo, Hf, Ta, W, Pt, Pb, Au and Ag. The molar fractions x, y, z and u meet the inequalities of 2≦x≦6, 16≦y≦20, 0.2≦z≦7 and 0.01≦u≦7, respectively. The alloy includes a metastable phase Z represented by at least one of a plurality of Bragg reflection peaks observable by X-ray diffraction analysis. The at least one peak corresponds to a lattice spacing of 0.179 nm±0.005 nm.

Abstract: A method of making an iron base magnetic material alloy powder includes the steps of: preparing an iron base magnetic material alloy containing at least 50% by mass of iron; and pulverizing the magnetic material alloy using a pin mill. A portion of the mill, which comes into contact with the magnetic material alloy, is made of a cemented carbide material at least partially.