Abstract: A magnetic field generator comprises a pair of pole-piece units. The pair of pole-piece units respectively include plate yokes. Each of the plate yokes includes a surface facing the other's and provided with a permanent magnet group and a pole piece. The pole piece includes an annular projection having a plurality of annular-projection pieces and a permanent magnet for reduction of magnetic flux leakage installed on an outside surface of each annular-projection piece. When assembling the pole piece, first, the permanent magnet for reduction of magnetic flux leakage is fixed on the outside surface of each annular-projection piece. At this time, the permanent magnet is slid on the flat outside surface of the annular-projection piece, to a desired position on the annular-projection piece, and then fixed. Each of the annular-projection pieces mounted with the permanent magnet is fixed on a base plate.

Abstract: A surface treating process according to the present invention, a vapor deposited film is formed from an easily oxidizable vapor-depositing material on the surface of a work by evaporating the vapor-depositing material in a state in which the vapor deposition controlling gas has been supplied to at least zones near a melting/evaporating source and the work within a treating chamber. Thus, the vapor deposited film can be formed stably on the surface of a desired work without requirement of a long time for providing a high degree of vacuum and without use of a special apparatus. In addition, the use of the surface treating process ensures that a corrosion resistance can be provided to a rare earth metal-based permanent magnet extremely liable to be oxidized, without degradation of a high magnetic characteristic of the magnet.

Abstract: A magnetic field adjusting apparatus calculates a location and the number of magnetic field adjusting pieces to be disposed, by means of a linear programming. A value corresponding to an expected magnetic field uniformity is calculated bed on the location and the number of adjusting pieces. The location and the number of the adjusting pieces for the value corresponding to the expected magnetic field uniformity not grater than a predetermined value are displayed in a display portion. The worker disposes the adjusting piece on a magnetic field generator based on the display. If the value corresponding too the expected magnetic field uniformity is greater than the predetermined value, a value corresponding to an expected magnetic field uniformity is further calculated by using a direct search. A location and the number of the adjusting pieces that minimize the value corresponding to the expected magnetic field uniformity are selected and displayed in the display portion.

Abstract: A marking method for a sintered product of the invention includes forming a concave portion on the sintered product by irradiating the sintered product with laser light thereby to write identification information on the sintered product. The depth of the concave portion is adjusted in a range between 0.1 &mgr;m and 5 &mgr;m, inclusive.

Abstract: A method for cutting a rare earth alloy of the invention using a wire having abrasive grains stuck thereon is disclosed. The method includes the step of cutting the rare earth alloy while supplying a cutting fluid having a predetermined kinematic viscosity between the wire and the rare earth alloy. The method further includes the step of varying the temperature of a supplied amount of fresh cutting fluid in order to control the kinematic viscosity of the cutting fluid.

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: Manufacture by rolling silicon steel having a silicon content of 3 wt % or greater and by rolling thin sendust sheet is implemented by powder metallurgical fabrication using powder as the starting raw material, and the average crystal grain size of the sheet-form sintered body or quick-cooled steel sheet is made 300 pm or less, whereby intra-grain slip transformation occurs after slip transformation in the grain boundaries, wherefore cold rolling is rendered possible. In addition, a mixture powder wherein pure iron powder and Fe—Si powder are mixed together in a prescribed proportion is fabricated with a powder metallurgy technique, and an iron-rich phase is caused to remain in the sintered body, whereby cold rolling is possible using the plastic transformation of those crystal grains. Furthermore, when a minute amount of a non-magnetic metal element such as Ti, V, or Al, etc.

Abstract: A compact is produced from an alloy powder for R—Fe—B type rare earth magnets including particles having a size in a range of about 2.0 &mgr;m to about 5.0 &mgr;m as measured by a light scattering method using a Fraunhofer forward scattering in a proportion of approximately 45 vol. % or more and particles having a size larger than about 10 &mgr;m in a proportion of less than about 1 vol. %. The compact is then sintered to obtain a R—Fe—B type rare earth magnet having an average crystal grain size in a range of about 5 &mgr;m to about 7.5 &mgr;m, and an oxygen concentration in a range of about 2.2 at. % to about 3.0 at. %.

Abstract: A method of making a material alloy for an iron-based rare earth magnet includes the step of forming a melt of an alloy with a composition of (Fe1-mTm)100-x-y-z-n(B1-pCp)xRyTizMn. T is Co and/or Ni; R is at least one element selected from Y (yttrium) and the rare earth elements; and M is at least one element selected from Al, Si, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, Hf, Ta, W, Pt, Au and Pb, wherein the following inequalities are satisfied: 10<x≦25 at %, *6≦y<10 at %, 0.5≦z≦12 at %, 0≦m≦0.5, 0≦n≦10 at % and 0≦p≦0.25. Next, the melt is fed onto a shoot with a guide surface tilted at about 1 degree to about 80 degrees with respect to a horizontal plane, thereby moving the melt onto a melt/roller contact region. The melt is then rapidly cooled using a chill roller to make a rapidly solidified alloy including an R2Fe14B phase.

Abstract: Magnetic alloy powder for a permanent magnet contains: R of about 20 mass percent to about 40 mass percent (R is Y, or at least one type of rare earth element); T of about 60 mass percent to about 79 mass percent (T is a transition metal including Fe as a primary component); and Q of about 0.5 mass percent to about 2.0 mass percent (Q is an element including B (boron) and C (carbon)). The magnetic alloy powder is formed by an atomize method, and the shape of particles of the powder is substantially spherical. The magnetic alloy powder includes a compound phase having Nd2Fe14B tetragonal structure as a primary composition phase. A ratio of a content of C to a total content of B and C is about 0.05 to about 0.90.

Abstract: A magnetic powder feeding method for feeding magnetic powder into a cavity of a pressing apparatus includes the steps of: providing magnetic powder outside of the cavity; forming a magnetic field in a space including the cavity; and moving the magnetic powder into the cavity using a force exerted on the magnetic powder by the magnetic field, while the magnetic powder is oriented in a direction of the magnetic field. In the method, the step of moving of the magnetic powder into the inside of the cavity is performed after the start of the application of the magnetic field.

Abstract: A method for producing a compact of rare earth alloy powder of the present invention includes: a powder-filling step of filling rare earth allow powder in a cavity formed by inserting a lower punch into a through hall of a die of a powder compacting machine; and a compression step of pressing the rare earth alloy powder while applying a magnetic field, the steps being repeated a plurality of times. When the (n+1)th (n is an integer equal to or more than 1) stage compression step is to be carried out, the top surface of a compact produced in the n-th stage compression step is placed at a position above the bottom surface of a magnetic portion of a die.

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: An La—Co ferrite magnet powder, in which Sr and Fe are replaced with La and Co, respectively, is made by carrying out a calcination process at a temperature higher than 1300° C. and equal to or lower than 1450° C. Fe has a magnetic moment oriented upwardly with respect to a crystal c-axis at a number of sites thereof, and also has an opposite magnetic moment oriented downwardly with respect to the crystal c-axis at another number of sites thereof. And Fe is replaced with Co at the greater number of sites thereof. As a result, high coercivity is attained. In this manner, coercivity can be increased while suppressing decrease in saturation magnetization &sgr;s.

Abstract: A method for producing X(BaZ.Sr1-Z)(Zn⅓.(TaM.Nb1-M)⅔)O3—Y(BaZ′.Sr1-Z′)(Ga½.Ta½)O3 solid solution system, characterized in that sintering is carried out at a temperature of 1400° C. to 1550° C. in an atmosphere of N2 containing oxygen in a concentration of 6% to 40% or sintering is carried out at a temperature of 1400° C. to 1550° C. after presintering at a temperature of 900° C. to 1300° C. This method is suitably used in order to constantly produce a dielectric porcelain composition for an electronic device which has a reduced temperature coefficient of resonance frequency and an excellent specific dielectric constant, and is uniform with respect to the quality distribution in one composition, by suppressing the evaporation of the Zn contained in a conventional porcelain composition of a perovskite type compound and adjusting the oxygen concentration in an atmosphere for sintering to a specific value without controlling a composition.

Abstract: A powder pressing apparatus comprises an upper punch, a lower punch and a die. A compact is formed by pressing a powder loaded in a cavity formed by the upper punch, the lower punch and the die. At least either one of the upper punch and the lower punch has a contacting surface for contact with the compact, formed with grooves. The compact adhering to the upper punch or the lower punch may be sprayed with a liquid such as water. Thereafter, the compact adhering to the upper punch or the lower punch is removed therefrom. Preferably, the grooves should be formed by milling at least at an end portion of the contacting surface, the contacting surface should have a surface roughness Ra=0.05 &mgr;m˜25 &mgr;m, the powder should have an average grain diameter of not greater than 1 &mgr;m, the grooves should be formed at an interval of 0.1 mm˜2.0 mm to a depth of 0.2 &mgr;m˜100.0 &mgr;m.

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 method for cutting a rare earth alloy of this invention includes cutting an object to be machined while supplying slurry containing dispersed abrasive grains between a wire and the object to be machined. The wire is driven with a drive member, at least a wire contact face of the drive member being composed of an organic polymer material. Cutting is carried out while a tension in a range between 14.7 N and 39.2 N is applied to the wire.