Abstract: The present invention is aimed at providing a method for producing an NdFeB sintered magnet having a higher coercivity and higher squareness of the magnetization curve than ever before. A method for producing an NdFeB sintered magnet according to the present invention includes the steps of forming a layer containing Dy and/or Tb on the surface of an NdFeB sintered magnet base material and then performing a grain boundary diffusion process for diffusing Dy and/or Tb from the aforementioned layer through the crystal grain boundaries of the magnet base material into the magnet base material by heating the magnet base material to a temperature equal to or lower than the sintering temperature thereof, and this method is characterized in that a) the content of a rare earth in a metallic state in the magnet base material is equal to or higher than 12.

Abstract: The present invention is aimed at providing a sintered magnet production system that can prevent the influences of a leaking magnetic field in an orienting process. A sintered magnet production system according to the present invention has a filling means 11 for filling an alloy powder into a filling/sintering container, a sintering means 13 for sintering the alloy powder, and an orienting means 12 with an air-core coil for producing a magnetic field for orienting the alloy powder in the filling/sintering container after the filling process and before the sintering process, the axis of the air-core coil being displaced from a straight line connecting the filling means 11 and the sintering means 13. The magnetic field leaking from the orienting means 12 is strongest on the extended line of the axis of the air-core coil and relatively weak in the direction perpendicular to the extended line.

Abstract: The objective of the present invention is to provide a method for making a NdFeB sintered magnet, capable of enhancing the effect of increasing the coercive force and preventing the instability of the effects, and in addition, being inexpensive. The method for making a NdFeB sintered magnet according to the present invention has processes of coating a NdFeB sintered magnet with a powder containing Dy and/or Tb, then heating the NdFeB sintered magnet, and thereby diffusing Rh in the powder into the NdFeB sintered magnet through a grain boundary, and is characterized in that the powder contains 0.5 through 50 weight percent of Al in a metallic state; and the amount of oxygen contained in the NdFeB sintered magnet is equal to or less than 0.4 weight percent.

Abstract: The present invention provides a method for producing a sintered NdFeB magnet having high coercivity and capable of being brought into applications without lowering its residual magnetic flux density or maximum energy product and without reprocessing. The method for producing a sintered NdFeB magnet according to the present invention includes applying a substance containing dysprosium (Dy) and/or terbium (Tb) to the surface of the sintered NdFeB magnet forming a base body and then heating the magnet to diffuse Dy and/or Tb through the grain boundary and thereby increase the coercivity of the magnet.

Abstract: In a method for forming an adhesive layer on the surface of a workpiece before the formation of a coating film containing a powder on the workpiece, the present invention provides a method for forming the adhesive layer having a desired thickness. This object is achieved by the following method: An adhesive layer formation medium m1 coated with an adhesive material is made to collide with a workpiece W so that the adhesive material is transferred from the adhesive layer formation medium m1 to the workpiece W and forms an adhesive layer on the workpiece. An adhesive layer having a desired thickness can be formed on the workpiece by regulating the thickness of the adhesive material applied to the surface of the adhesive layer formation medium (i.e. the amount of the adhesive material held by a single adhesive layer formation medium). This enables the thickness of the powder coating as the final product to be controlled as desired.

Abstract: To improve the performance of a rare-earth magnet, it is effective to use a low-oxidized powder having a small grain size. One objective of the present invention is to provide a method for manufacturing a sintered rare-earth magnet having a magnetic anisotropy, in which a very active powder having a small grain size can be safely used in a low-oxidized state. Another objective is to provide a method capable of efficiently manufacturing products having various shapes. In a weighing and loading section 41 and a high-density loading section 42, a fine powder as a material of the sintered rare-earth magnet having a magnetic anisotropy is loaded into a mold until its density reaches a predetermined level. Then, in a magnetic orientation section 43, the fine powder is oriented by a pulsed magnetic field. Subsequently, the fine powder is not compressed but immediately sintered in a sintering furnace 44.

Abstract: In a method for forming an adhesive layer on the surface of a workpiece before the formation of a coating film containing a powder on the workpiece, the present invention provides a method for forming the adhesive layer having a desired thickness. This object is achieved by the following method: An adhesive layer formation medium m1 coated with an adhesive material is made to collide with a workpiece W so that the adhesive material is transferred from the adhesive layer formation medium m1 to the workpiece W and forms an adhesive layer on the workpiece. An adhesive layer having a desired thickness can be formed on the workpiece by regulating the thickness of the adhesive material applied to the surface of the adhesive layer formation medium (i.e. the amount of the adhesive material held by a single adhesive layer formation medium). This enables the thickness of the powder coating as the final product to be controlled as desired.

Abstract: A powder compaction method in which a powder p is filled by air tapping or other suitable method into a mold 1, then while the mold 1 being filled with the powder, the powder particles are bound with each other without application of force from outside the mold to form a compact C, and then the compact C is taken out from the mold 1. This method produces a variety of shapes of the compact far greater than in conventional methods, and net shape manufacturing of products with complex shapes is made possible by this method. Because this method uses far less binder compared to MIM and PIM that are expected as methods for producing products with complicated shapes, the time needed for elimination of the binder is much shorter than in MIM and PIM.

Abstract: A powder compaction method in which a powder p is filled by air tapping or other suitable method into a mold 1, then while the mold 1 being filled with the powder, the powder particles are bound with each other without application of force from outside the mold to form a compact C, and then the compact C is taken out from the mold 1. This method produces a variety of shapes of the compact far greater than in conventional methods, and net shape manufacturing of products with complex shapes is made possible by this method. Because this method uses far less binder compared to MIM and PIM that are expected as methods for producing products with complicated shapes, the time needed for elimination of the binder is much shorter than in MIM and PIM.

Abstract: A powder compact is produced by disposing a foil or film-like mold member packed with a powder in a cavity of a rubber mold which is loaded in a die. The rubber mold, the foil or film-like type mold member and the powder packed in the foil or film-like mold member are compressed by a punch to obtain a powder compact. The powder compact with the foil or film-like mold member being attached thereto is removed, by pressure, from the rubber mold. Since the powder to be compressed into a compact is not packed directly in the cavity of the rubber mold, but is packed in the mold member, no part of the rubber mold is caught in the space formed by the powder that is in contact with the rubber mold. Accordingly, cracks and chips in the powder compact can be prevented even when the rubber mold is restored to its initial shape and many shape and size variations of the powder compact can be realized.

Abstract: The present invention relates to a packing method and an apparatuses implementing said method in which a material is packed into a container by an air tapping process in which the air-pressure state of the space comprising a container and a space part connected with said container, which space being loaded with the material, is switched several times from a low air-pressure state to a high air-pressure state alternately, while keeping said low air-pressure state equal to or higher than the atmospheric pressure existing outside said space, thereby preventing the material from getting blown up by the inflow of the atmospheric air outside the container and packing a material into said container homogeneously.

Abstract: A powder compaction method in which a powder p is filled by air tapping or other suitable method into a mold 1, then while the mold 1 being filled with the powder, the powder particles are bound with each other without application of force from outside the mold to form a compact C, and then the compact C is taken out from the mold 1. This method produces a variety of shapes of the compact far greater than in conventional methods, and net shape manufacturing of products with complex shapes is made possible by this method. Because this method uses far less binder compared to MIM and PIM that are expected as methods for producing products with complicated shapes, the time needed for elimination of the binder is much shorter than in MIM and PIM.

Abstract: A powder compaction method in which a powder p is filled by air tapping or other suitable method into a mold 1, then while the mold 1 being filled with the powder, the powder particles are bound with each other without application of force from outside the mold to form a compact C, and then the compact C is taken out from the mold 1. This method produces a variety of shapes of the compact far greater than in conventional methods, and net shape manufacturing of products with complex shapes is made possible by this method. Because this method uses far less binder compared to NM and PIM that are expected as methods for producing products with complicated shapes, the time needed for elimination of the binder is much shorter than in MIM and PIM.

Abstract: Constitution: Impact media m to which a powder is attached impinge an article 19 with an adhesive layer formed thereon so that the powder adheres to the surface of the article, in which the impact media comprises a magnetic material and are subject to a magnetic field.

Abstract: A method for packing a material includes air tapping material contained in a feeding hopper to pack it into a container which is to be filled with the material, and separating the material in the feeding hopper and the container into a portion of the material packed in the container where the material has a uniform density and a portion which is the material remaining in the feeding hopper. The air tapping process includes subjecting the space that is supplied with the material to be packed to air pressure which is switched alternately from a low pressure state to a high pressure state and back to a low pressure state or from a high pressure state to a low pressure state and then back to a high pressure state, in either case causing the material to be packed to a high density.

Abstract: The powder coating of the present invention was used for a method for forming coatings comprising the steps of making the powder coating adhere to an adhesive layer previously formed on the surface of a material to be coated, and then heating it, thereby forming a coating, comprising a resin particle containing a thermosetting resin, and a particle containing a curing agent.

Abstract: Magnetic materials comprising Fe, B, R (rare earth elements) and Co having a major phase of Fe--CO--B--R intermetallic compound(s) of tetragonal system, and sintered anisotropic permanent magnets consisting essentially of, by atomic percent, 8-30% R (at least one of rare earth elements inclusive of Y), 2-28% B, no less than 50% Co, and the balance being Fe with impurities. Those may contain additional elements M (Ti, Ni, Bi, V, Nb, Ta, Cr, Mo, W, Mn, Al, Sb, Ge, Sn, Zr, Hf) providing Fe--Co--B--R--M type materials and magnets.

Abstract: A elastically and reversibly deformable rubber mold for producing powder compacts is made of a material at least a part of which is a mixture of rubber and magnetic powder. In use, this rubber mold filled with the magnetic powder and subjected to a magnetic field and pressure with punches, thereby compressing the powder to form powder compact. This makes the distribution of magnetic field in the cavity of the rubber mold more homogeneous, and therefore, the distortion, cracking and chipping caused by inhomogeneity of the distribution of the magnetic field are reduced, so that the shape of the resultant powder compact is closer to the end product.

Abstract: The present invention relates to a packing method in which a material (p) is fed into a space comprising an opening (4c) for feeding the material and a space (4d) to be packed with said material, and said space is subjected to air tapping, that is, switching of air-pressure from a low air-pressure state to a high air-pressure state alternately, thereby packing the material into the space (4d) at a high packing-density. The use of air tapping for packing a material into a space makes the packing-density of the material uniform.

Abstract: An apparatus for producing a green compact includes a circuit that circulates die assemblies, each of which contains a rubber mold having rubber in at least its side portion. The apparatus also includes a high density filling device that has a feeder for feeding powder into the rubber molds; a pusher or a vibrator or both a vibrator and a pusher; a die press machine configured to impart a compaction force sufficient to produce the green compact to each of the circulating die assemblies in succession; and a device for removing the green compact from each rubber mold. The high-density filling device, the die-press machine and the removing device are successively arranged along the circuit. Each of the circulating die assemblies has sufficient structural integrity to withstand the compaction force because all structure necessary to withstand the compaction force is present in the circulating die assemblies.