摘要:
An R—Fe—B based rare-earth sintered magnet according to the present invention includes, as a main phase, crystal grains of an R2Fe14B type compound that includes Nd, which is a light rare-earth element, as a major rare-earth element R. The magnet includes a heavy rare-earth element RH (which is at least one of Dy and Tb) that has been introduced through the surface of the sintered magnet by diffusion. The magnet has a region in which the concentration of the heavy rare-earth element RH in a grain boundary R-rich phase is lower than at the surface of the crystal grains of the R2Fe14B type compound but higher than at the core of the crystal grains of the R2Fe14B type compound.
摘要:
An R—Fe—B based rare-earth sintered magnet according to the present invention includes, as a main phase, crystal grains of an R2Fe14B type compound that includes Nd, which is a light rare-earth element, as a major rare-earth element R. The magnet includes a heavy rare-earth element RH (which is at least one of Dy and Tb) that has been introduced through the surface of the sintered magnet by diffusion. The magnet has a region in which the concentration of the heavy rare-earth element RH in a grain boundary R-rich phase is lower than at the surface of the crystal grains of the R2Fe14B type compound but higher than at the core of the crystal grains of the R2Fe14B type compound.
摘要:
An R—Fe—B based anisotropic sintered magnet according to the present invention has, as a main phase, an R2Fe14B type compound that includes a light rare-earth element RL (which is at least one of Nd and Pr) as a major rare-earth element R, and also has a heavy rare-earth element RH (which is at least one element selected from the group consisting of Dy and Tb). In the crystal lattice of the main phase, the c-axis is oriented in a predetermined direction. The magnet includes a portion in which at least two peaks of diffraction are observed within a 2θ range of 60.5 degrees to 61.5 degrees when an X-ray diffraction measurement is carried out using a CuK α ray on a plane that is located at a depth of 500 μm or less under a pole face of the magnet and that is parallel to the pole face.
摘要:
An R—Fe—B based anisotropic sintered magnet according to the present invention has, as a main phase, an R2Fe14B type compound that includes a light rare-earth element RL (which is at least one of Nd and Pr) as a major rare-earth element R, and also has a heavy rare-earth element RH (which is at least one element selected from the group consisting of Dy and Tb). In the crystal lattice of the main phase, the c-axis is oriented in a predetermined direction. The magnet includes a portion in which at least two peaks of diffraction are observed within a 2θ range of 60.5 degrees to 61.5 degrees when an X-ray diffraction measurement is carried out using a CuK α ray on a plane that is located at a depth of 500 μm or less under a pole face of the magnet and that is parallel to the pole face.
摘要:
An object of the present invention is to provide a method for forming a uniform and dense electroplating film with high adhesion strength on the surface of an article, yet irrespective of the surface material and the surface properties of the article. A means for a solution of the problem comprises: forming on the surface of the article, a resin coating made of a resin containing dispersed therein a powder of a first metal; then forming a second-metal substituted plating film on the surface of the resin coating by immersing the resin-coated article in a solution containing ions of a second metal having an ionization potential nobler than that of the first metal; and further forming an electroplating film of a third metal on the surface of the metal-substituted plating film.
摘要:
A rare earth metal-based permanent magnet has a film layer formed substantially of only a fine metal powder on a metal forming the surface of the magnet. The rare earth metal-based permanent magnet having the film layer on its surface is produced in the following manner: A rare earth metal-based permanent magnet and a fine metal powder forming material are placed into a treating vessel, where both of them are vibrated and/or agitated, whereby a film layer made of a fine metal powder produced from the fine metal powder producing material is formed on a metal forming the surface of the magnet. Thus, the formation of a corrosion-resistant film such as plated film can be achieved at a high thickness accuracy by forming an electrically conductive layer uniformly and firmly on the entire surface of the magnet without use of a third component such as a resin and a coupling agent.
摘要:
The integrated magnet body according to the invention is an integrated magnet body formed by laminating and securing a plurality of pieces of magnet through an insulating film between pieces of magnet, characterized in that the insulating film has a film thickness of 0.01 &mgr;m or more, and a ratio of a total sum of the thickness of the insulating films to an overall length in the laminating direction of the integrated magnet body is in a range of from 0.0005 to 3%. The integrated magnet body according to the invention is excellent in insulating property and effective volume ratio and thus can attain high efficiency of a motor by installing the integrated magnet body in the motor.
摘要:
A hollow work having a hole communicating with the outside and a fine metal powder producing material are placed into a treating vessel, where the fine metal powder producing material is brought into flowing contact with the surface of the work, thereby adhering a fine metal powder produced from the fine metal powder producing material to the surface of the work. The hollow work may be a ring-shaped bonded magnet. Thus, a film having an excellent corrosion resistance can be formed without use of a third component such as a resin and a coupling agent by providing an electric conductivity to the entire surface of the magnet, i.e., not only to the outer surface (including end faces) but also to the inner surface of the magnet and subjecting the magnet to an electroplating treatment.
摘要:
The present invention provides an Fe—B—R based permanent magnet, which has a chemical conversion coating film formed on its surface with an aluminum film interposed therebetween, the chemical conversion coating film containing at least one of titanium and zirconium, phosphorus, oxygen and fluorine as constituting elements, and a process for producing such an Fe—B—R based permanent magnet. In the permanent magnet, the chemical conversion coating film is adhered firmly to the magnet with the aluminum film interposed therebetween and hence, the magnet is excellent in corrosion resistance. Even if the magnet is left to stand for a long time under high-temperature and high-humidity conditions of a temperature of 80° C. and a relative humidity of 90%, the magnet exhibits a stable high magnetic characteristic which cannot deteriorate. Moreover, the film is free from hexa-valent chromium.
摘要:
An Fe—B—R based permanent magnet and metal pieces are placed into a treating vessel, where they are vibrated and/or agitated, whereby a metal film is formed on the surface of the magnet. A sol solution produced by the hydrolytic reaction and the polymerizing reaction of a metal compound which is a starting material for a metal oxide film is applied to the metal film and subjected to a heat treatment to form a metal oxide film. Therefore, it is possible to form, on the surface of the magnet, a corrosion-resistant film which can be produced easily and at a low cost without carrying-out of a plating treatment or a treatment using hexa-valent chromium and which has an excellent adhesion to the surface of the magnet and can exhibit a stable high magnetic characteristic which cannot be degraded even if the magnet is left to stand for a long period of time under high-temperature and high-humidity conditions of a temperature of 80° C. and a relative humidity of 90%. Thus, it is possible to provide an Fe—B—R based permanent magnet having an excellent corrosion resistance.