Disclosed herein is a permanent magnet comprising: a plurality of aligned iron nitride nanoparticles wherein the iron nitride nanoparticles include α″-Fe.sub.16N.sub.2 phase domains; wherein a ratio of integrated intensities of an α″-Fe.sub.16N.sub.2 (004) x-ray diffraction peak to an α″-α″-Fe.sub.16N.sub.2 (202) x-ray diffraction peak for the aligned iron nitride nanoparticles is greater than at least 7%, wherein the diffraction vector is parallel to alignment direction, and wherein the iron nitride nanoparticles exhibit a squareness measured parallel to the alignment direction that is greater than a squareness measured perpendicular to the alignment direction.

The present invention relates to an R-T-B based permanent magnet material, having a composition of R.sub.xT.sub.yTm.sub.qB.sub.z (at. %), wherein 13≤x≤15.5, 0.5≤q≤3, 0.85≤z≤1, y=100−x−q−z; wherein R is LR.sub.aHR.sub.1-a, LR is one selected from the group consisting of Pr, Nd, PrNd, or a combination thereof, HR is one selected from the group consisting of Dy and Tb, or a combination thereof, and 0.95≤a≤1; wherein T is one selected from the group consisting of Fe and Co, or a combination thereof; and Tm is a transition metal. The advantage of the method is that: plating a heavy rare earth film on alloy flakes using a magnetron sputtering device, and the coercivity of the magnet is significantly increased simply by having a “core-shell” structure without long time diffusion heat treatment.

Some variations provide a permanent-magnet structure comprising: a region having a plurality of magnetic domains and a region-average magnetic axis, wherein each of the magnetic domains has a domain magnetic axis that is substantially aligned with the region-average magnetic axis, and wherein the plurality of magnetic domains is characterized by an average magnetic domain size. Within the region, there is a plurality of metal-containing grains characterized by an average grain size, and each of the magnetic domains has a domain easy axis that is dictated by a crystallographic texture of the metal-containing grains. The region has a region-average easy axis based on the average value of the domain easy axis within that region. The region-average magnetic axis and the region-average easy axis form a region-average alignment angle that has a standard deviation less than 30° within the plurality of magnetic domains. Many permanent-magnet structures are disclosed herein.

A method of forming a magnet is provided. The method includes disposing an anisotropic magnetic powder and a binder within a bed, the anisotropic magnetic powder having a defined magnetization direction. An energy beam selectively melts the binder such that the anisotropic magnetic powder forms a permanent magnet with the defined magnetization direction. The energy beam is a laser beam, a microwave beam and the like.

A NdFeB rare earth magnet includes a main phase and a grain boundary phase including a white grain boundary phase and a gray grain boundary phase. In a microstructure observation area of the rare earth magnet, an area of the white grain accounts for 1˜3% of a total area of the microstructure observation area, and an area of the gray grain boundary phase accounts for 2˜10% of the total area of the microstructure observation area.

Provided is a method of manufacturing a magnet capable of using only a single pole, whereby a combination force between a permanent (or referred to as a magnet) and a yoke (or referred to as a shielding metal) can be improved without performing a manual bonding work therebetween and then the efficiency of subsequent processes, such as polishing and plating, after combination and completeness of a product can be improved.

Techniques are disclosed concerning applied magnetic field synthesis and processing of iron nitride magnetic materials. Some methods concern casting a material including iron in the presence of an applied magnetic field to form a workpiece including at least one iron-based phase domain including uniaxial magnetic anisotropy, wherein the applied magnetic field has a strength of at least about 0.01 Tesla (T). Also disclosed are workpieces made by such methods, apparatus for making such workpieces and bulk materials made by such methods.

A dual-rotor machine comprising a dual rotor support structure rotatably connected to a frame. A stationary stator is disposed between the rotors and is fixed to the frame. An inner rotor and outer rotor, each comprising a permanent magnet Halbach array, are coaxially disposed with the stator and are rotable about the stator. In this configuration, the inner rotor channels its magnetic flux to its outside, while the outer rotor channels its magnetic flux to its inside. The magnetic flux density at the stator for the dual-rotor machine can be as high as 2 Tesla or higher for high-grade neodymium-iron-boron permanent magnet material, and the stored magnetic energy for conversion to mechanical or electrical energy available to the stator may be at least 0.5 kJ/m. The rotor Halbach arrays may comprise monolithic permanent magnets with continuously variable magnetic field direction.

A method is provided for producing an artificial permanent magnet, in a powder preparation step a main phase powder, which includes a rare-earth transition metal compound with permanently magnetic properties and has a first average particle size, is prepared and an anisotropic powder, which has a higher anisotropy field strength than the main phase powder and has a second average particle size, is prepared, wherein the second average particle size is smaller than the first average particle size. In a subsequent powder mixing step, the main phase powder and the anisotropic powder are mixed together to form a powder mixture and, in a subsequent heat treatment step, this powder mixture with the main phase powder of the first average particle size and with the anisotropic powder of the second average particle size is sintered to form an artificial permanent magnet.

This invention provides for a rare-earth permanent magnet-forming sintered body obtained by integrally sintering magnet material particles containing a rare-earth substance while shaping the magnet material particles, a rare-earth permanent magnet obtained by magnetizing the sintered body, and a rotary machine in which the permanent magnet is embedded.