Abstract: 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.

Abstract: A molded product having pores in its surface, an inorganic powder, a fat and oil and media are placed into a treating vessel, and a kinetic energy is supplied to the contents of the treating vessel, thereby forcing the inorganic powder into the pores and hardening it in the pores. In another process, a molded product having pores in its surface and an inorganic powder producing material are placed into a treating vessel, and a kinetic energy is supplied to the contents of the treating vessel, thereby forcing an inorganic powder produced from the inorganic powder producing material into the pores and hardening it in the pores. The inorganic powder producing material performs a role of producing an inorganic powder by the collision of pieces of the inorganic powder producing material against one another, against the molded product and against the inner wall of the vessel, and a role as media for forcing the produced inorganic powder into the pores.

Abstract: The present invention provides an electroplating device including an anode inserted through and disposed in a hole provided in a work and communicating with the outside, and a member for rotating the work about its center axis and supplying a plating electric current to the work. The present invention also provides an electroplating device including an anode inserted through and disposed in a hole provided in a work and communicating with the outside, a member for rotating the work about its center axis, and a member for supplying a plating electric current to the work. Further, the present invention provides an electroplating device including an anode inserted through and disposed in a hole provided in a work and communicating with the outside, and a means for allowing a plating solution in the hole in the work to flow.

Abstract: 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.

Abstract: An Fe—B—R based permanent magnet has a metal oxide film having a thickness of 0.01 &mgr;m to 1 &mgr;m on its surface with a metal film interposed therebetween. Thus, the film is excellent in adhesion to the surface of the magnet. Even if the permanent magnet is left to stand under high-temperature and high-humidity of a temperature of 80° C. and a relative humidity of 90% for a long period of time, the magnetic characteristic of the magnet cannot be degraded. The magnet has a thermal shock resistance enough to resist even a heat cycle for a long period of time in a temperature range of −40° C. to 85° C., and can exhibit a stable high magnetic characteristic. Therefore, it is possible to produce an Fe—B—R based permanent magnet having a corrosion-resistant film free from hexa-valent chromium.

Abstract: A resin molded product and a fine metal powder producing material are placed into a treating vessel. The fine metal powder producing material is brought into flowing contact with the surface of the resin molded product, thereby producing a fine metal powder, and forming a metal layer of the fine metal powder on the surface of the resin molded product. In this process, the metal layer of the fine metal powder can be formed firmly and at high density on the surface of the resin molded product. The metal layer exhibits a function as an electrically conductive layer. Therefore, a metal film having an excellent thickness accuracy, an excellent surface smoothness and a high peel strength can be formed in a simple manner on the metal layer by carrying out an electroplating treatment. In addition, it is possible for the metal layer itself to exhibit functions or properties such as an ornamentality.

Abstract: A method of manufacturing R—Fe—B bonded magnets, capable of forming various corrosion resisting films on a R—Fe—B bonded magnet uniformly with a very high bonded strength so as to attain such a very high corrosion resistance thereof that prevents the bonded magnet from being rusted even in a long-period high-temperature high-humidity test; comprising barrel-polishing a porous R—Fe—B bonded magnet by a dry method using as media an abrasive stone formed by sintering inorganic powder of Al2O3, SiC, ZrO and MgO, or a mixture of an abrasive for metal balls and vegetable media, such as vegetable skin chips, sawdust, rind of a fruit and a core of corn, or a mixture of vegetable media the surfaces of which are modified by the above-mentioned abrasive and the above-mentioned inorganic pulverized bodies, so as to enable a surface of the magnet to be smoothed and sealed.

Abstract: A resin molded product and a fine metal powder producing material are placed into a treating vessel. The fine metal powder producing material is brought into flowing contact with the surface of the resin molded product, thereby producing a fine metal powder, and forming a metal layer of the fine metal powder directly on the surface of the resin molded product. In this process, the metal layer of the fine metal powder can be formed firmly and at high density on the surface of the resin molded product. The metal layer exhibits a function as an electrically conductive layer. Therefore, a metal film having an excellent thickness accuracy, an excellent surface smoothness and a high peel strength can be formed in a simple manner on the metal layer by carrying out an electroplating treatment. In addition, it is possible for the metal layer itself to exhibit functions or properties such as an ornamentality.

Abstract: 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.

Abstract: The present invention provides an electroplating device including an anode inserted through and disposed in a hole provided in a work and communicating with the outside, and a member for rotating the work about its center axis and supplying a plating electric current to the work. Thus, a uniform plated film can be formed on both of the outer and inner surfaces of the work having the hole communicating with the outside such as a ring-shaped work, of which a ring-shaped bonded magnet is representative, by using the electroplating device.

Abstract: An Fe—B—R based permanent magnet has a metal oxide film having a thickness of 0.01 &mgr;m to 1 &mgr;m on its surface with a metal film interposed therebetween. Thus, the film is excellent in adhesion to the surface of the magnet. Even if the permanent magnet is left to stand under high-temperature and high-humidity of a temperature of 80° C. and a relative humidity of 90% for a long period of time, the magnetic characteristic of the magnet cannot be degraded. The magnet has a thermal shock resistance enough to resist even a heat cycle for a long period of time in a temperature range of −40° C. to 85° C., and can exhibit a stable high magnetic characteristic. Therefore, it is possible to produce an Fe—B—R based permanent magnet having a corrosion-resistant film free from hexa-valent chromium.

Abstract: An efficient method for producing a high-precision, very small metal ball, such as a Cu ball having an outer diameter not greater than 1 mm, comprising the steps of: cutting metal wire having a diameter not greater than 0.3 mm into a predetermined length; melting and solidifying the metal wires to form starting metal pieces (11); charging a plating apparatus having a double-tank structure comprising an outer splash-proofing tank (8) and an inner plating tank (3), comprising a cathode (4) located at a horizontally turning peripheral portion and an anode centrally located inside the tank; turning the inner tank (3) in a forward and reverse direction while plating solution is discharged to the outer tank (8) due to a high speed rotation of the inner tank at 50 to 800 rpm; and electroplating the starting material to form a film of predetermined thickness without generating aggregation of plated product.

Abstract: 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.

Abstract: An object of the present invention is to provide an Fe—B—R permanent magnet that exhibits stabilized high magnetic properties, wear resistance, electrical insulating performance, and corrosion resistance and shows minimized deterioration from the initial magnetic properties when exposed for an extended time to atmospheric conditions of a temperature of 80° C. and relative humidity of 90%, by providing a coating film having outstanding adhesion with the Fe—B—R permanent magnet and improved wear resistance and corrosion resistance. After cleaning the surface of the permanent magnet body by ion sputtering or the like, an Al or Ti coating film is formed on the surface of that magnet body by a vapor film-forming method such as ion plating, and then an aluminum oxide coating film is formed by a vapor film-forming method such as ion plating while introducing either simple O2 gas or a rare gas containing O2.

Abstract: 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%.