The present disclosure provides a technology of further improving magnetic properties (such as residual magnetic flux density) of NdFeB magnets. The method of producing an NdFeB magnet of the present disclosure comprises: producing a sintered body having a structure comprising a main phase and a grain boundary phase and having an NdFeB magnet composition in which Tw/(RwBw) is 2.26 to 2.50, wherein Rw represents a total percent (%) by weight of rare-earth elements and elements other than Fe, Ni, Co, B, N, and C, Tw represents a total percent (%) by weight of Fe, Ni, and Co, and Bw represents a total percent (%) by weight of B, N, and C; and heat treating the sintered body in a low temperature range of 580 C. to 640 C. and a high temperature range of 660 C. or more.

A method of processing a rare earth magnet comprises: a step of irradiating an R-T-B-based rare earth magnet with laser light to process; and a step of performing heat treatment on the magnet after the irradiating. The heat treatment includes: a step A of bringing the temperature of the magnet to 400 C. or less, a step B of holding the magnet at a temperature T1 in a range of 400 to 700 C. after the step A, and a step C of bringing the temperature of the magnet to less than 400 C. after the step B. The temperature of the magnet is made not to exceed 700 C. between the step A and the step B. The temperature of the magnet is made not to exceed 700 C. between the step B and the step C. A step of setting the magnet at a temperature higher than 700 C. after the step C is not included.

The present invention provides an R-T-B based sintered magnet having an R-T-B based compound as main phase grains, wherein, the content of Zr contained in the R-T-B based sintered magnet is 0.3 mass % to 2.0 mass %, the main phase grains have Zr, and the R-T-B based sintered magnet have main phase grains with the mass concentration of Zr at the edge portion of the main phase grain being 70% or less of that at the central portion of the main phase grain at the cross-section of the main phase grain.

The present invention is a method for producing a rare earth magnet, including preparing a magnetic powder and a modifier powder, mixing them to obtain a mixed powder, compression-molding the mixed powder in a magnetic field to obtain a magnetic-field molded body, and pressure-sintering the magnetic-field molded body to obtain a sintered body, wherein the magnetic powder includes a first particle group and a second particle group, the D.sub.50 values of the first particle group and the second particle group are denoted by d.sub.1 ?m and d.sub.2 ?m, respectively, d.sub.1 and d.sub.2 satisfy the relationship of 0.350?d.sub.2/d.sub.1?0.500, and the ratio between the total volume of the first particle group and the total volume of the second particle group is from 9:1 to 4:1; and a rare earth magnet obtained by the production method.

Improved manufacturing processes and resulting anisotropic permanent magnets, such as for example alnico permanent magnets, having highly controlled and aligned microstructure in the solid state are provided. A certain process embodiment involves applying a particular orientation and strength of magnetic field to loose, binder-coated magnet alloy powder particles in a compact-forming device as they are being formed into a compact in order to preferentially align the magnet alloy powder particles in the compact. The preferential alignment of the magnet alloy powder particle is locked in place in the compact by the binder after compact forming is complete. After removal from the device, the compact can be subjected to a subsequent sintering or other heat treating operation.

Provided are: a method for manufacturing a sintered body as a base of a sintered magnet and a method for manufacturing a permanent magnet. Specifically, a magnet raw material is pulverized into magnet powder, the magnet powder pulverized and a binder are mixed, thereby to form a compound. The, a formed body, obtained by forming the compound formed, is sintered by heating up the same to a firing temperature in a pressed state at a predetermined heat-up rate, and by keeping the same at the firing temperature. In the sintering step, the pressure value for pressing the formed body is set to: less than 3 MPa from the start of heating up of the formed body to a predetermined timing during heating up of the formed body; and 3 MPa or more after the timing.

An internally segmented magnet is disclosed. The magnet may include a first layer of a permanent magnetic material, a second layer of a permanent magnetic material, and an insulating layer separating the first and second layers. The insulating layer may include a ceramic mixture of at least a first ceramic material and a second ceramic material. The mixture having a melting point of up to 1,100 C. and may be a eutectic, or near eutectic, composition. The magnet may be formed by forming a first layer of powdered permanent magnetic material, depositing an insulating layer over the first layer, depositing a second layer of powdered permanent magnetic material over the insulating layer to form an internally segmented magnet stack, and sintering the magnet stack. The ceramic materials may include a halogen and an alkaline earth metal, alkali metal, or a metal having a +3 or +4 oxidation state.

The present invention provides a method for manufacturing a rare-earth magnet, the method comprising the steps of preparing a rare-earth magnet raw material powder including R, Fe and B as composition components (R is one or more elements selected from the rare earth elements including Y and Sc); packing the raw material powder into a molding die, and compacting and molding the raw material powder while applying a magnetic field, wherein, in the compacting and molding step, compacting is performed biaxially, in the directions of X and Y axes, when the magnetic field is applied in the direction of Z axis.

This application concerns a magnet having a magnet body as well as a method for manufacturing such a magnet. The magnet body has a first region with first magnetic properties and a second region with second magnetic properties that are different to the first properties. Owing to the manufacturing process of the magnet body, the relative location of the first region and the second region within the magnet body is freely predeterminable.

New types of particle feedstocks and heterogeneous grain structures are provided for rare earth permanent magnets (REPMs) and their production in a manner to significantly enhance toughness of the magnet with little or no sacrifice in the hard magnetic properties. The novel tough REPMs made from the feedstock have heterogeneous grain structures, such as bi-modal, tri-modal, multi-modal, laminated, gridded, gradient fine/coarse grain structures, or other microstructural heterogeneity and configurations, without changing the chemical compositions of magnets.