There are provided a spherical silver powder which has the same diameter as that of a spherical silver powder produced by a conventional wet reduction method and which can sufficiently sinter the silver particles thereof to cause the silver particles to be adhered to each other at a relatively low temperature to form a conductive film having a low volume resistivity when it is used for a baked type conductive paste, and a method for producing the same. A spherical silver powder, which contains a neutral or basic amino acid having a carbon number of not less than 5 in each of particles thereof and which has an average particle diameter D.sub.50 of 0.2 to 5 μm based on a laser diffraction method, is produced by adding the neutral or basic amino acid having the carbon number of not less than 5 (such as proline, tyrosine, tryptophan, phenylalanine, arginine or histidine) to a water reaction system containing silver ions to mix a reducing agent therewith to deposit silver particles by reduction.

There are provided a spherical silver powder which has the same diameter as that of a spherical silver powder produced by a conventional wet reduction method and which can sufficiently sinter the silver particles thereof to cause the silver particles to be adhered to each other at a relatively low temperature to form a conductive film having a low volume resistivity when it is used for a baked type conductive paste, and a method for producing the same. A spherical silver powder, which contains a neutral or basic amino acid having a carbon number of not less than 5 in each of particles thereof and which has an average particle diameter D.sub.50 of 0.2 to 5 μm based on a laser diffraction method, is produced by adding the neutral or basic amino acid having the carbon number of not less than 5 (such as proline, tyrosine, tryptophan, phenylalanine, arginine or histidine) to a water reaction system containing silver ions to mix a reducing agent therewith to deposit silver particles by reduction.

The dust core comprises a plurality of soft magnetic iron-based particles, a coating layer disposed on each of the surfaces of the soft magnetic iron-based particles, an interstitial layer disposed between the coating layers, and a nanopowder disposed between the soft magnetic iron-based particles. The coating layer is a layer of a compound comprising Fe, Si, O, B and N; and the nanopowder is a powder of a compound comprising O, N and at least one element selected from the group consisting of Fe, Si, Zr, Co, Al, Mg, Mn and Ni.

The present disclosure relates to a silver powder preparation method comprising: a silver powder preparation step of preparing a silver salt, which comprises silver ions, and then reducing the silver ion so as to precipitate silver particles; a silver powder recovery step of separating silver particles from an aqueous solution or a slurry, which comprises the precipitated silver particles, and then washing and drying same to recover silver powder; and a silver powder coating step of injecting a pH adjuster into the recovered silver powder to adjust the pH, and then injecting a coating agent to coat after the pH adjustment. The pH adjuster is used in the silver powder coating step to adjust the pH, and thus, when silver power is used in a conductive paste, as the rate of change in viscosity over time is low, a conductive paste having excellent viscosity stability can be provided.

The present disclosure relates to a silver powder preparation method comprising: a silver powder preparation step of preparing a silver salt, which comprises silver ions, and then reducing the silver ion so as to precipitate silver particles; a silver powder recovery step of separating silver particles from an aqueous solution or a slurry, which comprises the precipitated silver particles, and then washing and drying same to recover silver powder; and a silver powder coating step of injecting a pH adjuster into the recovered silver powder to adjust the pH, and then injecting a coating agent to coat after the pH adjustment. The pH adjuster is used in the silver powder coating step to adjust the pH, and thus, when silver power is used in a conductive paste, as the rate of change in viscosity over time is low, a conductive paste having excellent viscosity stability can be provided.

Provided are: a production method for silver fine particles that retain capabilities such as conductivity and make it possible to form wiring at even lower temperatures; and silver fine particles. A silver fine particle production method in which silver powder is used to produce silver fine particles by means of a gas phase method. The silver fine particle production method has a step for supplying an organic acid to the silver fine particles. The gas phase method is, for example, a plasma method or a flame method. The silver fine particles have a surface coating that includes at least a carboxyl group.

Provided are: a production method for silver fine particles that retain capabilities such as conductivity and make it possible to form wiring at even lower temperatures; and silver fine particles. A silver fine particle production method in which silver powder is used to produce silver fine particles by means of a gas phase method. The silver fine particle production method has a step for supplying an organic acid to the silver fine particles. The gas phase method is, for example, a plasma method or a flame method. The silver fine particles have a surface coating that includes at least a carboxyl group.

The present invention provides a contact member that strikes a balance between low electrical resistance and sliding durability under the condition of load as low as about 0.1 N. A contact member of the invention has a metal base and a coating disposed on at least part of the metal base. The coating contains fluorinated oil having a polar group, and metal particles surface-treated with a fluorine-based compound having a polar group.

A method for producing a thin-walled metal part with complex geometry includes mixing a metal powder with a polymer binder in order to obtain a composite mixture, producing a flexible composite sheet from the composite mixture, cutting, in the flexible composite sheet, a preform based on a contour of the metal part, applying the preform in a mold having a surface configured with a relief of the metal part, and debinding and sintering the preform in order to obtain the metal part.

A method for producing a thin-walled metal part with complex geometry includes mixing a metal powder with a polymer binder in order to obtain a composite mixture, producing a flexible composite sheet from the composite mixture, cutting, in the flexible composite sheet, a preform based on a contour of the metal part, applying the preform in a mold having a surface configured with a relief of the metal part, and debinding and sintering the preform in order to obtain the metal part.