Abstract: Provided is a dust core excellent in flux density, iron loss, and mechanical strength. A production process of a dust core according to the invention includes a step of compacting a mixture obtained by mixing an iron-based soft magnetic powder for powder compact having a phosphate conversion coating film on the surface of an iron-based soft magnetic powder with a lubricant to obtain a powder compact, a heat treatment step of heating the resulting powder compact at 550° C. or more but not more than 650° C. in an inert atmosphere, and a heat treatment step of heating the heat-treated powder compact at 420° C. or more but not more than 530° C. in an oxidizing atmosphere.

Abstract: A method produces a dust core by molding a mixture through compression molding to give a powder compact, the mixture containing an oxygen-source-releasable compound and an iron-based soft magnetic powder for powder compacts including an iron-based soft magnetic matrix powder and an insulating coating film present on the surface of the matrix powder; and heating the powder compact to oxidize at least the surface of the iron-based soft magnetic matrix powder by the action of the oxygen-source-releasable compound. The resulting dust core excels not only in mechanical strength but also in resistivity (insulation).

Abstract: Disclosed is a composite wound element (Tra) which is used in a transformer or a transformation system, and used as a composite wound element for a noise-cut filter, wherein a plurality of coils (1) are enclosed in a magnetic connection member (2a), and are configured by winding belt-like conductive members (11, 12, 13) so that the width direction of the conductive members (11, 12, 13) corresponds to the axial direction of the coils (1). The transformer, the transformation system, and the composite wound element for a noise-cut filter are provided with the composite wound element having the aforementioned structure. Thus, the composite wound element (Tra), the transformer, the transformation system, and the composite wound element for a noise-cut filter can be produced more easily than ever before.

Abstract: The present invention relates to an iron-base powder for a powder core, wherein when cross-sections of at least 50 iron-base powders are observed and a crystal grain size distribution containing at least a maximum crystal grain size is determined by measuring a crystal grain size of each iron-base powder, 70% or more of the measured crystal grains are a crystal grain having a crystal grain size of 50 ?m or more. According to the iron-base powder of the invention, a coercivity of the powder core can be made small and a hysteresis loss can be reduced.

Abstract: Provided is an iron-based soft magnetic powder for dust core having a less coercive force, which is obtained by specifying the amount of inclusions in the iron-based powder for dust core, and at the same time, capable of decreasing the coercive force of a dust core produced using the iron-based soft magnetic powder. The iron-based soft magnetic powder for dust core is characterized by that when the cross-section of the iron-based soft magnetic powder particle is observed with a scanning electron microscope, the number of inclusions having an equivalent circle diameter from 0.1 to 3 ?m is 1×104 pieces/mm2 or less and the number of inclusions having an equivalent circle diameter exceeding 3 ?m is 10 pieces/mm2 or less.

Abstract: Provided is a dust core excellent in flux density, iron loss, and mechanical strength. A production process of a dust core according to the invention includes a step of compacting a mixture obtained by mixing an iron-based soft magnetic powder for powder compact having a phosphate conversion coating film on the surface of an iron-based soft magnetic powder with a lubricant to obtain a powder compact, a heat treatment step of heating the resulting powder compact at 550° C. or more but not more than 650° C. in an inert atmosphere, and a heat treatment step of heating the heat-treated powder compact at 420° C. or more but not more than 530° C. in an oxidizing atmosphere.

Abstract: An axial motor includes a rotor arranged between a pair of stators with coils. In the rotor, a plurality of permanent magnets sandwiched between pairs of first magnetic materials and a plurality of second magnetic materials are alternately arranged in a rotation direction while gaps are provided therebetween. Since the permanent magnets are sandwiched by the first magnetic materials in the thus constructed axial motor, a field-weakening control can be performed. Since the second magnetic materials are provided, a reluctance torque can be generated. Further, since the gaps are provided, more magnetic fluxes generated from the permanent magnets can be caused to flow toward the coils. Therefore, the thus constructed axial motor can achieve a higher output, higher torque, higher efficiency, and miniaturization.

Abstract: Provided is a reactor that enables high inductance to be generated with stability in a wide current range, while minimizing noise, processing cost, and eddy-current loss. The reactor (D1) has the ratio (t/W) of the width (W) to the thickness (t) of a conductive member that composes an air-core coil configured to be 1 or less, and preferably, 1/10 or less. Furthermore, the reactor also has the absolute value of a value ((L1?L2)/L3) that has had: the difference (L1?L2) between; the space interval (L1) between an inner wall face of a first core member (3) and an inner wall face of a second core member (4), at the innermost circumference position of the air-core coil (1); and the space (L2) between the inner wall face of the first core member (3) and the inner wall face of the second core member (4), at the outermost circumference position of the air-core coil (1); divided by an average value (L3); configured to be 1/50 or less.

Abstract: An iron-based soft magnetic powder for dust core having a high magnetic flux density, maintaining high electric insulation even after annealing, and more excellent in the mechanical strength in which a coating film having a phosphate conversion coating film is formed on the surface thereof and the peak height for the absorption of hydroxyl groups formed at 3700 cm?1 to 2500 cm?1 is 0.04 or more being indicated by absorbance when the coating film is analyzed by infrared diffuse reflectance spectroscopy.

Abstract: The invention relates to an iron-based soft magnetic powder for a dust core, wherein a film comprising Fe and Co, a phosphoric acid-based chemical conversion film and a silicone resin film are formed in this order on the surface of an iron-based soft magnetic powder, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core. The invention also relates to an iron-based soft magnetic powder for a dust core formed by coating the surface of an iron-based soft magnetic powder with an insulating film, wherein the powder has a particle diameter of from 45 ?m to 180 ?m, the insulating film is composed of two layers in which a lower layer composed of a phosphoric acid-based chemical conversion film and an upper layer composed of a silicone resin film, and each of the films has a thickness of from 100 nm to 280 nm, and to a dust core obtained by molding the iron-based soft magnetic powder for a dust core.

Abstract: Disclosed herein is an iron powder for dust cores which effectively keeps insulation among iron powder particles and excels in mechanical strength even though the amount of insulating material is reduced to achieve high-density forming and which also exhibits good thermal stability necessary for electrical insulating properties even after heat treatment at high temperatures. The iron-based magnetic powder has layers of phosphoric acid-based film and silicone resin film sequentially formed on the surface thereof, said phosphoric acid-based film containing at least one element selected from the group consisting of Co, Na, S, Si, and W.

Abstract: An iron-based soft magnetic powder for dust core includes an iron-based soft magnetic matrix powder, and arranged thereon in the following order, a phosphate coating and a silicone resin coating. The phosphate coating contains P, Co, Na, and S in combination with at least one of Al and Cs. This iron powder for dust core has superior mechanical strength, in which effective insulation is achieved between iron powdery particles even when the amount of an insulating material is reduced for realizing high-density molding. The iron powder for dust core is also superior in thermal stability, so that electrical insulation is maintained even after a heat treatment at high temperatures.

Abstract: The present invention relates to an iron-base powder for a powder core, wherein when cross-sections of at least 50 iron-base powders are observed and a crystal grain size distribution containing at least a maximum crystal grain size is determined by measuring a crystal grain size of each iron-base powder, 70% or more of the measured crystal grains are a crystal grain having a crystal grain size of 50 ?m or more. According to the iron-base powder of the invention, a coercivity of the powder core can be made small and a hysteresis loss can be reduced.

Abstract: Disclosed herein is a hydrogen permeable member composed of a metal porous body and a hydrogen permeable membrane placed thereon, with a diffusion preventing layer interposed between them, wherein the metal porous body has those parts on which the diffusion preventing layer is absent and such parts are filled with metal oxide particles and/or porous metal oxide. This structure prevents direct contact between the metal porous body and the hydrogen permeable membrane, thereby relieving the latter from deterioration by diffusion of metal from the former.

Abstract: A zeolite membrane support for supporting a zeolite membrane includes a metal substrate having a metal oxide layer at its surface. Preferably, the metal oxide layer has a thickness in the range of 1 nm to 10 ?m and comprises chromia, silica, or alumina. Preferably, the metal substrate is porous, having a mean pore size in the range of 10 nm to 50 ?m, and comprises an iron-based metal. A zeolite composite membrane includes the zeolite membrane support and a zeolite membrane which includes an external zeolite layer lying over the surface at and/or an internal zeolite layer lying in the pores at the metal oxide layer side of the zeolite membrane support. The zeolite membrane preferably has a composition satisfying the relationship SiO2/Al2O3?10.

Abstract: A supporting base of sufficient length and small diameter for supporting a gas separation membrane comprising a sintered material is provided. This supporting base has a high gas permeability, and allows omission of operation such as welding. This supporting base is produced by continuously extruding raw metal powder materials a and b corresponding to each constituent layer of the bilayer structure in the order starting from the raw metal powder material a constituting the inner layer to the raw metal powder material b constituting the outer layer such that the layer newly extruded surrounds the preceding layer to thereby produce a green cylinder of bilayer structure having an outer diameter of 15 mm or less; cutting the resulting green cylinder to a length of 100 mm or more; and sintering the green cylinder to thereby produce the supporting base for gas separation membrane.

Abstract: A mixed powder useful as a starting material for dust core comprises a uniform mixture of a soft magnetic powder and a binder resin so that the resultant dust core has an electric resistance capable of suppressing an eddy current between the soft magnetic powdery particles and high mechanical strength at room temperatures and also at high temperatures. In the mixed powder, the binder resin is made of a phenolic resin powder which has a methylol groups in the molecule and preferably has an average particle size of 30 &mgr;m or below and wherein when the phenolic resin powder is dissolved in boiling methanol in large excess, a content of an undissolved matter is at least 4 wt % based on the total of the phenolic resin. A dust core obtained from the mixed powder and its fabrication method are also described.

Abstract: Disclosed is a method for the compaction of a soft magnetic powder capable of manufacturing a green compact which has attained high density and high strength, is excellent in mechanical properties and magnetic properties, and does not cause a reduction in electrical resistance. Soft magnetic powder particles individually surface-coated with an insulating vitreous layer containing P, Mg, B, and Fe as essential components are used, and a lubricant is applied to the inner wall surface of a compaction die. The soft magnetic powder is subjected to compaction at from not less than room temperature to less than 50° C. without mixing the lubricant with the soft magnetic powder, followed by annealing at from 50 to 300° C.

Abstract: A mixed powder useful as a starting material for dust core comprises a uniform mixture of a soft magnetic powder and a binder resin so that the resultant dust core has an electric resistance capable of suppressing an eddy current between the soft magnetic powdery particles and high mechanical strength at room temperatures and also at high temperatures. In the mixed powder, the binder resin is made of a phenolic resin powder which has a methylol groups in the molecule and preferably has an average particle size of 30 &mgr;m or below and wherein when the phenolic resin powder is dissolved in boiling methanol in large excess, a content of an undissolved matter is at least 4 wt % based on the total of the phenolic resin. A dust core obtained from the mixed powder and its fabrication method are also described.

Abstract: Disclosed is a method for the compaction of a soft magnetic powder capable of manufacturing a green compact which has attained high density and high strength, is excellent in mechanical properties and magnetic properties and does not cause a reduction in electrical resistance. Soft magnetic powder particles individually surface-coated with an insulating vitreous layer containing P, Mg, B, and Fe as essential components are used, and a lubricant is applied to the inner wall surface of a compaction die. The soft magnetic powder is subjected to compaction at from not less than room temperature to less than 50° C. without mixing the lubricant with the soft magnetic powder, followed by annealing at from 50 to 300° C..