Provided is a negative electrode active material that can improve the discharge capacity per volume and charge-discharge cycle characteristics. The negative electrode active material according to the present embodiment contains an alloy phase. The alloy phase undergoes thermoelastic diffusionless transformation when releasing metal ions or occluding metal ions. The oxygen content of the negative electrode active material is not more than 5000 ppm in mass.

A method of making a machine component includes extruding a supply of an aluminum alloy to produce an extrusion. The extrusion is formed under temperature-limited forming conditions of 275 C. or less to produce a blank. The blank is machined to at least one predetermined tolerance to produce the machine component.

A method of making a machine component includes extruding a supply of an aluminum alloy to produce an extrusion. The extrusion is formed under temperature-limited forming conditions of 275 C. or less to produce a blank. The blank is machined to at least one predetermined tolerance to produce the machine component.

A method for manufacturing a rare-earth iron-based ring magnet includes: (a) obtaining a rare-earth iron-based magnet powder; (b) preparing a compound; (c) forming a green body; (d) inserting the green body into a composite mold, setting the composite mold in a spark plasma sintering (SPS) apparatus, and degreasing the green body by energization at a predetermined current density while applying a pressure to the green body under reduced pressure to obtain a degreased body; and (e) sintering the degreased body by energization at a current density while applying a pressure to the degreased body to obtain a rare-earth iron-based ring magnet.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

The present disclosure is directed at methods of preparing rare earth-based permanent magnets having improved coercivity and remanence, the method comprising one or more steps comprising: (a) homogenizing a first population of particles of a first GBM alloy with a second population of particles of a second core alloy to form a composite alloy preform, the first GBM alloy being substantially represented by the formula: AC.sub.bR.sub.xCo.sub.yCu.sub.dM.sub.z, the second core alloy being substantially represented by the formula G.sub.2Fe.sub.14B, where AC, R, M, G, b, x, y, and z are defined; (b) heating the composite alloy preform particles to form a population of mixed alloy particles; (c) compressing the mixed alloy particles, under a magnetic field of a suitable strength to align the magnetic particles with a common direction of magnetization and inert atmosphere, to form a green body; (d) sintering the green body; and (e) annealing the sintered body. Particular embodiments include magnets comprising neodymium-iron-boron core alloys, including Nd.sub.2Fe.sub.14B.

Provided is a rare-earth magnet containing no heavy rare-earth metals such as Dy or Tb in a grain boundary phase, has a modifying alloy for increasing coercivity (in particular, coercivity under a high-temperature atmosphere) infiltrated thereinto at lower temperature than in the conventional rare-earth magnets, has high coercivity, and has relatively high magnetizability, and a production method therefor. The rare-earth magnet RM includes a RE-FeB-based main phase MP with a nanocrystalline structure (where RE is at least one of Nd or Pr) and a grain boundary phase BP around the main phase, the grain boundary phase containing a RE-X alloy (where X is a metallic element other than heavy rare-earth elements). Crystal grains of the main phase MP are oriented along the anisotropy axis, and each crystal grain of the main phase, when viewed from a direction perpendicular to the anisotropy axis, has a plane that is quadrilateral in shape or has a close shape thereto.

Provided is a rare-earth magnet containing no heavy rare-earth metals such as Dy or Tb in a grain boundary phase, has a modifying alloy for increasing coercivity (in particular, coercivity under a high-temperature atmosphere) infiltrated thereinto at lower temperature than in the conventional rare-earth magnets, has high coercivity, and has relatively high magnetizability, and a production method therefor. The rare-earth magnet RM includes a RE-FeB-based main phase MP with a nanocrystalline structure (where RE is at least one of Nd or Pr) and a grain boundary phase BP around the main phase, the grain boundary phase containing a RE-X alloy (where X is a metallic element other than heavy rare-earth elements). Crystal grains of the main phase MP are oriented along the anisotropy axis, and each crystal grain of the main phase, when viewed from a direction perpendicular to the anisotropy axis, has a plane that is quadrilateral in shape or has a close shape thereto.

A MnBi-based magnetic powder, which contains a hexagonal MnBi-based magnetic phase containing Sn and has a Sn content of 0.2 to 5 at % with respect to a sum of Mn, Bi and Sn, is provided. In addition, a bond magnet containing a kneaded product of this MnBi-based magnetic powder with a resin binder is provided. Furthermore, a MnBi-based metal magnet, which contains a hexagonal MnBi-based magnetic phase containing Sn and has a Sn content of 0.2 to 5 at % with respect to a sum of Mn, Bi and Sn, is provided.

Disclosed is an R-T-BGa-based magnet material ahoy where R is at least one element selected from rare earth metals including Y and excluding Gd, Tb, Dy, Ho, Er, TM, Yb, and Lu, and Tis one or more transition metals with Fe being an essential element. The R-T-BGa-based magnet material alloy includes: an R.sub.2T.sub.14B phase 3 which is a principal phase, and an R-rich phase (1 and 2) which is a phase enriched with the R, wherein a non-crystalline phase 1 in the R-rich phase has a Ga content (mass %) that is higher than a Ga content (mass %) of a crystalline phase 2 in the R-rich phase. With this, it is possible to enhance the magnetic properties of rare earth magnets that are manufactured from the alloy and reduce variations in the magnetic properties thereof.