A manufacturing method for a bonded magnet, in particular a manufacturing method for an anisotropic bonded magnet. The present invention solves the problem that the existing manufacturing method under the condition of heating magnetic powders performs magnetic field orientation after a binder is melted, resulting in low production efficiency, a complicated mould structure, high process costs, thereby affecting wide use of an anisotropic bonded magnet. A manufacturing method for an anisotropic bonded magnet comprising the following steps: 1) mixing anisotropic magnetic powders and a thermosetting binder; 2) adding the mixture of step 1) to a mould cavity, performing pressure forming under an oriented magnetic field, and performing demagnetization, so as to obtain a green body; and 3) loading the green body of step 2) into a vacuum furnace for thermal curing, so as to obtain an anisotropic bonded magnet. In the present application, forming is performed in a magnetic field at normal temperature or in a cold state, avoiding magnetic powders being bonded to each other, improving the effect of magnetic field orientation, and the mould has a simple structure, is easy to operate, and provides high efficiency, thereby lowering cost.

A two-step diffusion method for preparing high-performance dual-main-phase sintered mischmetal-iron-boron magnet belongs to the preparing technical field of rare earth permanent magnet materials. The compositions of the two main phase alloys are RE-Fe—B (RE is Nd or Pr) and (Nd, MM)-Fe—B (MM is mischmetal), respectively. First, PrHoFe strip-casting alloy is used as a diffusion source. Next, a PrHo-rich layer is uniformly coated on the surface of (Nd, MM)-Fe—B hydrogen decrepitation powders. The higher anisotropic fields of Pr.sub.2Fe.sub.14B and Ho.sub.2Fe.sub.14B are used to improve the coercivity. Then, the ZrCu strip-casting alloy is used as a diffusion source. A Zr-rich layer is uniformly coated on the surface of the powders after the first-step diffusion, which prevents the growth of the MM-rich main phase grains during the sintering process and the inter-diffusion between the two main phases, thus obtains high coercivity.

This invention provides methods for fabricating a hard or soft magnet with tailorable magnetic and crystallographic orientations. Methods are disclosed to individually tailor three-dimensional voxels for selected crystallographic orientations and, independently, selected magnetic orientations with location specificity throughout a magnet. Some variations provide a method of making a magnet, comprising: providing a feedstock composition containing magnetic or magnetically susceptible materials; exposing the feedstock composition to an energy source for melting, thereby generating a first melt layer; solidifying the first melt layer in the presence of an externally applied magnetic field, thereby generating a magnetic metal layer containing a plurality of individual voxels; optionally repeating to generate a plurality of solid layers; and recovering a magnet comprising the magnetic metal layer(s), wherein the externally applied magnetic field has a magnetic-field orientation that is selected to control a magnetic axis and a crystallographic texture within the magnetic metal layer(s).

A strip cast alloy containing Nd in excess of the stoichiometry of Nd.sub.2Fe.sub.14B is subjected to HDDR treatment and diffusion treatment, yielding microcrystalline alloy powder in which major phase crystal grains with a size of 0.1-1 μm are surrounded by Nd-rich grain boundary phase with a width of 2-10 nm. The powder is finely pulverized, compacted, and sintered, yielding a sintered magnet having a high coercivity.

A Sm—Fe—N-based magnet powder that includes a Sm—Fe—N-based magnetic material powder, wherein an average particle size of the Sm—Fe—N-based magnetic material powder is not larger than 5 μm, and a full width at half maximum of a diffraction peak of a (220) plane in an X-ray diffraction profile of the Sm—Fe—N-based magnetic material powder is not larger than 0.0033 Å. Also disclosed is a Sm—Fe—N-based sintered magnet that includes a sintered body of a Sm—Fe—N-based magnetic material, wherein an average grain size of crystal grains of the Sm—Fe—N-based magnetic material is not larger than 5 μm, and a full width at half maximum of a diffraction peak of a (220) plane in an X-ray diffraction profile of the Sm—Fe—N-based magnetic material is not larger than 0.0033 Å.

A bond magnet includes filaments bonded with each other to form a shape of the bond magnet. Each of the filaments is a filamentous member including a resin material and magnetic powder dispersed in the resin material, and has magnetic anisotropy for high degree of freedom of magnetic flux direction and high surface magnetic flux density on a working surface.

A method for preparing a Nd—Fe—B-based sintered magnet. The method includes: 1) providing a master alloy and an auxiliary alloy, the master alloy being a Nd—Fe—B alloy ingot or cast strip, the auxiliary alloy being a heavy rare earth alloy; 2) breaking up the master alloy using a hydrogen decrepitation process to yield a crude powder, conducting hydrogen absorption treatment on the auxiliary alloy and breaking up the hydrogenated auxiliary alloy to yield hydride particles; 3) uniformly mixing and stirring the crude powder of the master alloy and the hydride particles of the auxiliary alloy to yield a mixture; 4) milling the mixture obtained in step 3) to yield powders; 5) uniformly stirring the powders obtained in step 4) and conducting orientation forming treatment on the powders, to yield a raw body of a Nd—Fe—B based magnet; and 6) sintering the raw body of the Nd—Fe—B based magnet.

The present invention discloses a short process preparation technology of sintered NdFeB magnets from the NdFeB sludge, which relates to a field of recycle technology of NdFeB sludge. The present invention comprises the following steps: water bath distillation of organics in sludge, ultrasonic cleaning, calcium reduction and diffusion, ultrasonic rinsing in a magnetic field and drying, powders mixing and sintering. NdFeB sludge as raw materials was directly prepared from recycled sintered magnets with high magnetic properties. Most of the organics in the sludge could be removed by a vacuum distillation process with stepwise heating. The ultrasonic rinsing process in a magnetic field could effectively remove the remaining organics. The recycled sintered magnets exhibited good maximum energy product [(BH).sub.max] of 35.26 MGOe. The present invention has important features, such as the short processing time, efficient environmental protection, high recycling rate and effective utilization rate of rare earth metals.

Provided are a rare-earth magnet capable of realizing a high magnetic flux amount without using any back yoke, and a linear motor comprising a movable element using the rare-earth permanent magnet. A rare-earth permanent magnet-forming sintered body for forming a permanent magnet is integrally sintered while being formed into a given three-dimensional shape with a lengthwise cross-section having a first surface extending in a length direction thereof, a second surface lying at a distance from the first surface in a thickness direction thereof and extending in the length direction, and an edge surface of each of lengthwise opposite ends thereof. This sintered body is formed such that easy magnetization axes of the magnet material particles included in a central region thereof are oriented in such a manner as to be directed along an arch-shaped path.

A sintered R.sub.2M.sub.17 magnet is provided that comprises at least 70 Vol % of a Sm.sub.2M.sub.17 phase, wherein R is at least one of the group consisting of Ce, La, Nd, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yt, Lu and Y, and M comprises Co, Fe, Cu and Zr. In an area of the R.sub.2M.sub.17 sintered magnet of 200 by 200 μm viewed in a Kerr micrograph, an areal proportion of demagnetised regions after application of an internal opposing field of 1200 kA/m is less than 5% or less than 2%.