Embodiment of the present invention provides a cylindrical composite permanent magnet and a magnetic assembly including the same, wherein the cylindrical composite permanent magnet comprises at least one annular permanent magnet having a first magnetic parameter value and at least one annular permanent magnet having a second magnetic parameter value, wherein the at least one annular permanent magnet having the first magnetic parameter value and at least one annular permanent magnet having the second magnetic parameter value are jointed to form the cylindrical composite permanent magnet. The cylindrical composite permanent magnet in the invention is obtained by jointing at least one annular permanent magnet having the first magnetic parameter value and at least one annular permanent magnet having the second magnetic parameter value; the magnetic property of the cylindrical composite permanent magnet can be adjusted by selecting the material type and length of the joint annular permanent magnet.

There is provided a production method and a production device for producing each of the rare earth sintered magnet sintered bodies without carrying a mold in a sintering furnace. The method includes feeding an alloy powder into a mold having side walls divided into two or more sections; filling the alloy powder into the mold to prepare a filled molded-body; orienting the alloy powder in the filled molded-body by applying a magnetic field to the filled molded-body to prepare an oriented filled-molded-body; detaching the side walls of the mold from the oriented filled-molded-body and retrieving the oriented filled-molded-body from the mold; and sintering the retrieved oriented filled-molded-body. The filling step and the orienting step are performed at different locations. A pulsed magnetic field can be applied in the orienting step and inside of the mold can be partitioned into a plurality of cavities by partitions.

A method for producing an MSMA, a magnetic material or a magnetic item via additive manufacturing, comprising: (a) providing or forming a layer of magnetic/ferromagnetic particles; (b) applying a magnetic field, having a first three-dimensional (3D) magnetic field vector with respect to an origin point of a 3D coordinate system, to the layer of particles or portion thereof, either while pressure is or is not applied to hold the particles in place, to align the magnetic moments of the magnetic particles in the layer or portion thereof during or after the providing or forming of the layer or portion thereof; (c) applying means for binding the layer wherein means for binding may comprise a binder material or complete/partial sintering of the layer; (d) providing or forming a next layer of magnetic/ferromagnetic particulate material on to the previous layer; (e) applying a magnetic field, having a next 3D magnetic field vector with respect to the origin point of the 3D coordinate system, to the next layer of particles or portion thereof, either while pressure is or is not applied to hold the particles in place, to align the magnetic moments of the magnetic particles in the next layer or portion thereof during or after the providing or forming of the next layer or portion thereof; and (f) applying means for binding the next layer wherein means for binding may comprise a binder material or complete/partial sintering of next layer.

Apparatus and methods for manufacturing magnets, and magnets, having magnetically oriented grains, and apparatus including such magnets. The field of a permanent magnet may be shaped by applying an external field to the material from which the magnet is made in such a way as to magnetize different regions of the material in different directions. The apparatus may include, and the methods may involve, a metal-powder press that may press metal powder in the presence of a magnetic field. The press may compress the powder in an axial direction. The field may have flux lines that are transverse to the axial direction. The field may have flux lines that are along the axial direction.

This invention provides for a rare-earth permanent magnet-forming sintered body having an integral sintered structure of magnet material particles containing a rare-earth substance. The integral sintered structure is formed in a three-dimensional shape having: a cross-section with a shape defined by a radially outer-side arc-shaped surface having a first curvature radius, a radially inner-side arc-shaped surface having a second curvature radius less than the first curvature radius and having an arc shape concentric with the outer-side arc-shaped surface; and a first end face and a second end face each of which is a radially-extending face along a virtual radial line extending from a curvature center of the arc shapes; and an axial length extending in a direction perpendicular to the cross-section.

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one a-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one a-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

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.

The present invention aims to provide a NdFeB system sintered magnet capable of improving the magnetization characteristic. The NdFeB system sintered magnet is a NdFeB system sintered magnet with the c axis oriented in one direction, characterized in that: the median of the grain size of the crystal grains at a section perpendicular to the c axis is 4.5 m or less, and the area ratio of the crystal grains having grain sizes of 1.8 m or smaller on the aforementioned section is 5% or lower. The median of the grain size is decreased (to 4.5 m or less), whereby improve the coercive force is improved. Simultaneously, the area ratio of the crystal grains having grain sizes of 1.8 m or smaller is decreased (to 5% or lower) to reduce the number of crystal grains having no magnetic wall formed, whereby the magnetization characteristic is improved.

A magnet and a method of forming the magnet are provided. The method includes forming a slurry comprising magnetic powder material and binder material and creating raw layers from the slurry. A magnetic field is applied to the raw layers to orient the magnetic powder material in a desired direction, and each layer is cured to form another layer on the most recent cured layer. The layers are attached together.

In one embodiment, a magnet includes a plurality of layers, each layer having a microstructure of sintered particles. The particles in at least one of the layers are characterized as having preferentially aligned magnetic orientations in a first direction.