An alloy for R-T-B-based rare earth sintered magnets which contains R which is a rare earth element; T which is a transition metal essentially containing Fe; a metallic element M containing one or more metals selected from Al, Ga and Cu; B and inevitable impurities, in which R accounts for 13 at % to 15 at %, B accounts for 4.5 at % to 6.2 at %, M accounts for 0.1 at % to 2.4 at %, T accounts for balance, a proportion of Dy in all rare earth elements is in a range of 0 at % to 65 at %, and the following Formula 1 is satisfied,
0.0049Dy+0.34≤B/TRE≤0.0049Dy+0.36  Formula 1
wherein Dy represents a concentration (at %) of a Dy element, B represents a concentration (at %) of a boron element, and TRE represents a concentration (at %) of all the rare earth elements.

The disclosure discloses a method for preparing a permanent magnet material. In this method, an ionic liquid electroplating process is used to electroplate a heavy rare earth metal onto a surface of a sintered magnet to form a magnet with a coating, wherein the sintered magnet has a thickness of 10 mm or less in at least one direction; in the ionic liquid electroplating process, an electroplating solution comprises an ionic liquid, a heavy rare earth salt, a group VIII metal salt, an alkali metal salt and an additive, an anode is a heavy rare earth metal or a heavy rare earth alloy, a cathode is the sintered magnet, an electroplating temperature is 20-50° C., an electroplating time is 15-80 min. The preparation method of the disclosure can improve an intrinsic coercive force of the magnet with low cost and high production efficiency. A utilization rate of heavy rare earth is high.

A method for producing a sintered R-T-B based magnet includes applying an adhesive agent to an application area of the magnet, adhering a particle size-adjusted powder of a heavy rare-earth element RH which is at least one of Dy and Tb to the application area, and heating at a temperature which is equal to or lower than a sintering temperature of the magnet to allow the element RH in the particle size-adjusted powder to diffuse from the surface into the interior of the magnet. The particle size of the particle size-adjusted powder is set so that, when powder particles are placed on the entire surface of the magnet to form a single particle layer, the amount of element RH in the particle size-adjusted powder is in a range from 0.6 to 1.5% with respect to the magnet by mass ratio.

Provided are: a sintered body that forms a rare-earth magnet and is configured in a manner such that the divergence between the orientation angles of the easy axes of magnetization of magnet material particles and the orientation axis angle of the magnet material particles is kept within a prescribed range in an arbitrary micro-section of a magnet cross-section; and a rare-earth sintered magnet. This sintered body for forming a rare-earth magnet has two or more different regions exhibiting an orientation axis angle of at least 20, given that the orientation axis angle is defined as the highest-frequency orientation angle among the orientation angles of the easy magnetization axes, relative to a pre-set reference line, of a plurality of magnet material particles in a rectangular section at an arbitrary position in a plane including the thickness direction and the widthwise direction.

A method of manufacturing a permanent magnet comprises a solution heat treatment. The solution heat treatment includes: performing a heat treatment at a temperature T.sub.ST; placing a cooling member including a first layer and a second layer on the first layer between the heater and the treatment object so that the first layer faces the treatment object; and transferring the treatment object together with the cooling member to the outside of a heating chamber, and cooling the treatment object until a temperature of the treatment object becomes a temperature lower than a temperature T.sub.ST200 C. In the step of cooling the treatment object, a cooling rate until the temperature of the treatment object becomes the temperature T.sub.ST200 C. is 5 C./s or more.

A rare earth permanent magnet that is high in residual magnetization and coercivity is obtained and includes R and T. A main phase of crystal grains having an Nd.sub.5Fe.sub.17 type crystal structure is included. In an X-ray diffraction profile drawn by performing an XRD measurement for a rare earth permanent magnet, peaks of detected intensity are present in specific ranges. In which the detected intensity of the peak with the highest detected intensity in the range of 41.60<2()<42.80 is set as , the detected intensity of the peak with the highest detected intensity in the range of 34.38<2()<34.64 is set as , and the detected intensity of the peak with the highest detected intensity in the range of 38.70<2()<41.20 is set as , 0.38</<0.70 and 0.45</<0.70 are established. The peak with the highest detected intensity in the range of 34.38<2()<34.64 is a peak derived from the Nd.sub.5Fe.sub.17 type crystal structure.

When a slurry in which a rare-earth-compound powder is dispersed is applied to sintered magnet bodies 1 and dried to apply the powder thereto, the sintered magnet bodies 1 are conveyed by a conveyer 2 and made to pass through the slurry 4 to apply the slurry to the sintered magnet bodies 1. Furthermore, a plurality of push-up members 51, which pass through insertion holes 22 provided in a conveyor belt 21, and protrude above the conveyor belt, are used to temporarily push up the sintered magnet bodies 1, and temporarily separate the conveyor belt 21 and the sintered magnet bodies 1. As a result, the slurry can be efficiently applied, even mass production can be suitably dealt with, and the slurry can be uniformly and reliably applied to the entire surface of each of the sintered magnet bodies.

There are provided a rare-earth permanent magnet and a manufacturing method of a rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture 12 is prepared by mixing the magnet powder and a binder, and the mixture 12 is formed into a sheet-like shape to obtain a green sheet 14. Thereafter, magnetic field orientation is performed to the green sheet 14, which is then held for several hours in a non-oxidizing atmosphere at a pressure higher than normal atmospheric pressure, at 200 through 900 degrees Celsius for calcination. Thereafter, the calcined green sheet 14 is sintered at a sintering temperature. Thereby a permanent magnet 1 is manufactured.

The present invention relates to a method of producing a composite component, the method including: preparing a second composite by fitting a first molded body onto a first composite including a rare earth magnet and a component contacting the rare earth magnet, such that the first molded body covers at least the entire surface of the first composite corresponding to the rare earth magnet; and forming a second molded body by inserting the second composite into a mold and injection-molding a thermoplastic resin such that the thermoplastic resin covers at least the entire surface of the first composite not covered by the first molded body and also contacts the first molded body.

There are provided a rare-earth permanent magnet and a manufacturing method of a rare-earth permanent magnet capable of preventing deterioration of magnet properties. In the method, magnet material is milled into magnet powder. Next, a mixture 12 is prepared by mixing the magnet powder and a binder, and the mixture 12 is formed into a sheet-like shape to obtain a green sheet 14. Thereafter, magnetic field orientation is performed to the green sheet 14, which is then held for several hours in a non-oxidizing atmosphere at a pressure higher than normal atmospheric pressure, at 200 through 900 degrees Celsius for calcination. Thereafter, the calcined green sheet 14 is sintered at a sintering temperature. Thereby a permanent magnet 1 is manufactured.