A manufacturing method of alloy powder comprises a liquid film forming step, a supplying step and a dividing step. In the liquid film forming step, a high speed fluid made of coolant liquid is shaped into a liquid film which has a predetermined thickness of 0.1 mm or more and receives a predetermined acceleration of 2.0×10.sup.4G or more along a thickness direction. In the supplying step, molten alloy which is not divided into a size of the predetermined thickness or less is supplied to the liquid film. In the dividing step, the molten alloy is divided into the size of the predetermined thickness or less by the high speed fluid to make alloy particles and keeping the alloy particles in the liquid film by the predetermined acceleration so that the alloy particles are continuously cooled in the high speed fluid.

A manufacturing method of alloy powder comprises a liquid film forming step, a supplying step and a dividing step. In the liquid film forming step, a high speed fluid made of coolant liquid is shaped into a liquid film which has a predetermined thickness of 0.1 mm or more and receives a predetermined acceleration of 2.0×10.sup.4G or more along a thickness direction. In the supplying step, molten alloy which is not divided into a size of the predetermined thickness or less is supplied to the liquid film. In the dividing step, the molten alloy is divided into the size of the predetermined thickness or less by the high speed fluid to make alloy particles and keeping the alloy particles in the liquid film by the predetermined acceleration so that the alloy particles are continuously cooled in the high speed fluid.

A method for producing hard metal powder suitable for manufacturing hard metal products including metal carbides and a binder is provided. An easy to carry out method that provides high quality hard metal powder includes: a) dissolving in water, water soluble raw materials and a binder source to form an aqueous solution, b) drying the aqueous solution to form a precursor powder having the raw materials homogenously distributed throughout the precursor powder, c) decomposing the precursor powder by heating the powder in an inert atmosphere to remove gas evolved in the decomposition of the raw materials, d) grinding the precursor powder and mixing it with a liquid media to produce a suspension, e) spray drying the suspension to agglomerate the precursor powder, and f) heat treating the agglomerated precursor powder to form a hard metal powder containing agglomerates of carbides evenly distributed and bonded to a metallic matrix.

To provide a method for efficiently producing metal microparticles having a particle diameter of 1 μm to 10 μm, and a device for producing the same. A metal microparticle production method is used, which includes a particle generating step of generating primary particles by irradiating a metal lump in a solvent in a first tank with an ultrasonic wave, and a particle splitting step of irradiating the primary particles with an ultrasonic wave in a solvent in a second tank and splitting the primary particles to produce secondary particles. Further, a metal microparticle production device is used, which includes: a first tank that has a solvent and a metal lump; a first heating unit that heats the solvent in the first tank; a first ultrasonic vibrator that is disposed in the first tank and irradiates the metal lump with an ultrasonic wave to generate primary particles; a second tank that has the solvent and the primary particles; and a second ultrasonic vibrator that irradiates the primary particles with an ultrasonic wave to split the primary particles.

A magnetic bead contains: a magnetic metal powder; and a coating layer with which a particle surface of the magnetic metal powder is coated. When the magnetic bead is left to stand in a state of a dispersion obtained by dispersing the magnetic bead in water, a time until an initial absorbance of the dispersion attenuates to 80% of an absorbance when the standing is started is 90 seconds or longer.

A silver powder which has a small content of carbon and which is difficult to be agglutinated, and a method for producing the same. While a molten metal, which is prepared by melting silver to which 40 ppm or more of copper is added, is allowed to drop, a high-pressure water is sprayed onto the molten metal to rapidly cool and solidify the molten metal to produce a silver powder which contains 40 ppm or more of copper, 0.1% by weight or less of carbon and 0.1% by weight or less of oxygen and wherein the particle diameter (D50 diameter) corresponding to 50% of accumulation in volume-based cumulative distribution of the silver powder, which is measured by means of a laser diffraction particle size analyzer, is in the range of from 1 μm to 15 μm, the average particle diameter (SEM diameter) of single particles being in the range of from 1 μm to 8 μm when it is measured by means of a field emission scanning electron microscope (SEM), the ratio (SEM diameter/D50 diameter) of the SEM diameter to the D50 diameter being in the range of from 0.3 to 1.0.

A silver powder which has a small content of carbon and which is difficult to be agglutinated, and a method for producing the same. While a molten metal, which is prepared by melting silver to which 40 ppm or more of copper is added, is allowed to drop, a high-pressure water is sprayed onto the molten metal to rapidly cool and solidify the molten metal to produce a silver powder which contains 40 ppm or more of copper, 0.1% by weight or less of carbon and 0.1% by weight or less of oxygen and wherein the particle diameter (D50 diameter) corresponding to 50% of accumulation in volume-based cumulative distribution of the silver powder, which is measured by means of a laser diffraction particle size analyzer, is in the range of from 1 m to 15 m, the average particle diameter (SEM diameter) of single particles being in the range of from 1 m to 8 m when it is measured by means of a field emission scanning electron microscope (SEM), the ratio (SEM diameter/D50 diameter) of the SEM diameter to the D50 diameter being in the range of from 0.3 to 1.0.

The invention relates to a method for producing hard metal powder suitable for manufacturing hard metal products comprising metal carbides and a binder. To provide a method which is easy to carry out and which provides high quality hard metal powder, the method is characterized by the steps of: a) dissolving in water, water soluble raw materials and a binder source to form an aqueous solution, b) drying the aqueous solution to form a precursor powder having the raw materials homogenously distributed throughout the precursor powder, c) decomposing the precursor powder by heating the powder in an inert atmosphere to remove gas evolved in the decomposition of the raw materials, d) grinding the precursor powder and mixing it with a liquid media to produce a suspension, e) spray drying the suspension to agglomerate the precursor powder, and f) heat treating the agglomerated precursor powder to form a hard metal powder containing agglomerates of carbides evenly distributed and bonded to a metallic matrix.

To provide a method for efficiently producing metal microparticles having a particle diameter of 1 m to 10 m, and a device for producing the same. A metal microparticle production method is used, which includes a particle generating step of generating primary particles by irradiating a metal lump in a solvent in a first tank with an ultrasonic wave, and a particle splitting step of irradiating the primary particles with an ultrasonic wave in a solvent in a second tank and splitting the primary particles to produce secondary particles. Further, a metal microparticle production device is used, which includes: a first tank that has a solvent and a metal lump; a first heating unit that heats the solvent in the first tank; a first ultrasonic vibrator that is disposed in the first tank and irradiates the metal lump with an ultrasonic wave to generate primary particles; a second tank that has the solvent and the primary particles; and a second ultrasonic vibrator that irradiates the primary particles with an ultrasonic wave to split the primary particles.

An object of the present invention is to provide a copper alloy powder for lamination shaping comprising a copper alloy, a method for producing a lamination shaped product and a lamination shaped product, which can achieve coexistence of mechanical strength and conductivity. One aspect of the present invention relates to a copper alloy powder for lamination shaping, comprising at least one additive element having a solid solution amount to copper of less than 0.2 at %.