A step of, while a powder of an RLM alloy (where RL is Nd and/or Pr; M is one or more elements selected from among Cu, Fe, Ga, Co, Ni and Al) which is produced through atomization and a powder of an RH compound (where RH is Dy and/or Tb) are present on the surface of a sintered R-T-B based magnet, performing a heat treatment at a sintering temperature of the sintered R-T-B based magnet or lower is included. The RLM alloy contains RL in an amount of 65 at % or more, and the melting point of the RLM alloy is equal to or less than the temperature of the heat treatment. The heat treatment is performed while the RLM alloy powder and the RH compound powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of RLM alloy:RH compound=9.6:0.4 to 5:5.

A step of, while a powder of an RLM alloy (where RL is Nd and/or Pr; M is one or more elements selected from among Cu, Fe, Ga, Co, Ni and Al) which is produced through atomization and a powder of an RH compound (where RH is Dy and/or Tb) are present on the surface of a sintered R-T-B based magnet, performing a heat treatment at a sintering temperature of the sintered R-T-B based magnet or lower is included. The RLM alloy contains RL in an amount of 65 at % or more, and the melting point of the RLM alloy is equal to or less than the temperature of the heat treatment. The heat treatment is performed while the RLM alloy powder and the RH compound powder are present on the surface of the sintered R-T-B based magnet at a mass ratio of RLM alloy:RH compound=9.6:0.4 to 5:5.

A hydrogen storage alloy suitable for a negative electrode of an on-board alkaline storage battery, and an alkaline storage battery using the alloy, which has an AB.sub.3-type crystal structure as a main phase, represented by: (Sm.sub.xLa.sub.yR.sub.z).sub.1−a−bMg.sub.aT.sub.bNi.sub.cCo.sub.dMe. (R is selected from Pr, Nd; T is selected from Ti, Zr, Hf; M is selected from V, Nb, Ta, Cr, Mo, W, Mn, Fe, Cu, Al, Si, P, B; the following conditions are met: 0<x<1.0, 0<y<1.0, 0.8≤x+y≤1.0, x+y+z=1.0; 0.93≤(x−y).Math.(1−a−b)+4.5(a+b)≤1.62, 0<a≤0.45, 0≤b≤0.05, 0≤d≤0.7, 0≤e≤0.15, 2.85≤c+d+e≤3.15 and 0.01≤d+e).

A hydrogen storage alloy suitable for a negative electrode of an on-board alkaline storage battery, and an alkaline storage battery using the alloy, which has an AB.sub.3-type crystal structure as a main phase, represented by: (Sm.sub.xLa.sub.yR.sub.z).sub.1−a−bMg.sub.aT.sub.bNi.sub.cCo.sub.dMe. (R is selected from Pr, Nd; T is selected from Ti, Zr, Hf; M is selected from V, Nb, Ta, Cr, Mo, W, Mn, Fe, Cu, Al, Si, P, B; the following conditions are met: 0<x<1.0, 0<y<1.0, 0.8≤x+y≤1.0, x+y+z=1.0; 0.93≤(x−y).Math.(1−a−b)+4.5(a+b)≤1.62, 0<a≤0.45, 0≤b≤0.05, 0≤d≤0.7, 0≤e≤0.15, 2.85≤c+d+e≤3.15 and 0.01≤d+e).

A precipitation-strengthened cast product welding repair method is a method of repairing a damaged portion of a precipitation-strengthened cast product. The method includes: forming a first weld layer on a surface of the damaged portion by micro tungsten inert gas (TIG) welding using a solid-solution-strengthened welding material having higher toughness than the cast product; and forming a second weld layer on the first weld layer by building up the second weld layer by laser welding using a dual multi-phase nanostructure intermetallic compound as a welding material and being higher in heat supply rate than the micro TIG welding.

A precipitation-strengthened cast product welding repair method is a method of repairing a damaged portion of a precipitation-strengthened cast product. The method includes: forming a first weld layer on a surface of the damaged portion by micro tungsten inert gas (TIG) welding using a solid-solution-strengthened welding material having higher toughness than the cast product; and forming a second weld layer on the first weld layer by building up the second weld layer by laser welding using a dual multi-phase nanostructure intermetallic compound as a welding material and being higher in heat supply rate than the micro TIG welding.

A method and a plant for the production of a powdery starting material, which is provided for the manufacture of rare earth magnets, are disclosed. First of all, at least one magnetic material, which is comminuted into a powdery intermediate product with a possibly increased concentration of impurities, and/or at least one alloy including rare earth metal are provided, which includes a low concentration of impurities. A classification of the powdery intermediate product to at least one criterion takes place subsequently, wherein, for the classification of the powdery intermediate product with the increased concentration of impurities, at least one dynamic classifier is provided, which divides the powdery intermediate product with impurities into at least two fractions based on the at least one criterion, wherein at least a high concentration of impurities accumulates in a first fraction and no impurities or at least a lower concentration of impurities than in the case of the first fraction accumulate in a second fraction, and wherein the fraction without impurities or with a low concentration of impurities forms the starting material for the manufacture of rare earth magnets.

According to an embodiment, a composite permanent magnet includes a matrix of magnetically hard phase grains having an average grain size of 10 nm to 50 μm; and magnetically soft phase grains embedded within the matrix, and having an average grain size of at least 50 nm, each grain having an elongated shape with an aspect ratio of at least 2:1. According to another embodiment, a composite permanent magnet includes a matrix of magnetically hard phase grains having an average grain size of 10 nm to 50 μm; and magnetically soft phase grains embedded within the matrix, and having an average grain width of at least 50 nm, an average grain height of 20 to 500 nm, and an aspect ratio of at least 2:1. According to yet another embodiment, a method of forming a composite permanent magnet is also provided.

Methods for the production of magnetic powders, compacted magnetic bodies and sintered magnetic bodies. The methods include the use of metal carboxylate precursor compounds such as metal oxalates. The precursor compounds are heated under pressure to form metal alloy particles which can be directly formed into compacted magnetic bodies or can be further refined by using a reductant at elevated temperatures and pressures. The sintered magnetic bodies may have strong magnetic properties even if produced in the absence of a strong magnetic field.

A composition of a nickel based alloy mixture which can be used for welding via especially liquid metal deposition or as a powder bed of an additive manufacturing method. A metallic powder mixture includes (in wt %): a cobalt (Co) or nickel (Ni) based super alloy with a content of 20% to 60%, a NiCoCrAlY-composition with a content of 70% to 30% and a metallic braze material with a content between 10% to 5%. The melting point of the braze material is at least 10K lower than the melting point of the nickel or cobalt based superalloy.