Provided is a copper alloy powder which is a metal powder to be used for additive manufacturing by a laser beam system, and which is able to achieve a higher laser absorption rate and additionally suppress heat transfer through necking, and a method for producing this copper alloy powder. A copper alloy powder which contains one or more elements selected from among Cr, Zr and Nb in a total amount of 15 wt % or less, with a balance being made up of Cu and unavoidable impurities, and which is characterized in that a coating film containing Si atoms is formed on the copper alloy powder, and a Si concentration in the copper alloy powder with the coating film is 5 wt ppm or more and 700 wt ppm or less.

Provided is a copper alloy powder which is a metal powder to be used for additive manufacturing by a laser beam system, and which is able to achieve a higher laser absorption rate and additionally suppress heat transfer through necking, and a method for producing this copper alloy powder. A copper alloy powder which contains one or more elements selected from among Cr, Zr and Nb in a total amount of 15 wt % or less, with a balance being made up of Cu and unavoidable impurities, and which is characterized in that a coating film containing Si atoms is formed on the copper alloy powder, and a Si concentration in the copper alloy powder with the coating film is 5 wt ppm or more and 700 wt ppm or less.

An example of a method, for three-dimensional (3D) printing, includes applying a build material and patterning at least a portion of the build material. The patterning includes selectively applying a wetting amount of a binder fluid on the at least the portion of the build material and subsequently selectively applying a remaining amount of the binder fluid on the at least the portion of the build material. An area density in grams per meter square meter (gsm) of the wetting amount ranges from about 2 times less to about 30 times less than area density in gsm of the remaining amount.

An example of a method, for three-dimensional (3D) printing, includes applying a build material and patterning at least a portion of the build material. The patterning includes selectively applying a wetting amount of a binder fluid on the at least the portion of the build material and subsequently selectively applying a remaining amount of the binder fluid on the at least the portion of the build material. An area density in grams per meter square meter (gsm) of the wetting amount ranges from about 2 times less to about 30 times less than area density in gsm of the remaining amount.

Disclosed herein are methods for electrolessly coating copper onto a chromium metal powder, the method comprising adding a nickel-coated chromium powder to an aqueous electroless copper plating bath comprising a source of copper cations, a copper-cation complexing agent, a copper-cation reducing agent, and a first base, thereby forming a copper-coated chromium metal powder. Also disclosed are copper-coated chromium metal powders prepared by a disclosed method.

Disclosed herein are methods for electrolessly coating copper onto a chromium metal powder, the method comprising adding a nickel-coated chromium powder to an aqueous electroless copper plating bath comprising a source of copper cations, a copper-cation complexing agent, a copper-cation reducing agent, and a first base, thereby forming a copper-coated chromium metal powder. Also disclosed are copper-coated chromium metal powders prepared by a disclosed method.

A hopper and method for transferring raw material, which can prevent segregation due to the impact caused by falling of the raw material powder when different types of raw material powders are transferred. The hopper for a raw material powder according to one embodiment of the present disclosure includes: a hopper body having an inner space in which the raw material powder is stored and including an outlet which is formed through the lower end thereof and through which the raw material powder is discharged; a transfer pipe to which the raw material powder discharged through the outlet is transferred and which has a region, through which the raw material powder is transferred, divided into a plurality of regions; and a slide gate unit disposed between the outlet and the transfer pipe to open or close the transfer pipe while adjusting a degree of opening of the transfer pipe.

To provide a titanium-based porous body that has high void fraction to ensure gas permeability and water permeability for practical use as an electrode and a filter, has a large specific surface area to ensure conductivity and sufficient reaction sites with a reaction solution or a reaction gas, thus showing excellent reaction efficiency, and contains less contaminants because of no organic substance used. A titanium-based porous body having a specific void fraction and a high specific surface area is obtained by filling an irregular-shaped titanium powder having an average particle size of 10 to 50 μm in a dry system without using any binder or the like into a thickness of 4.0×10.sup.−1 to 1.6 mm, and sintering the irregular-shaped titanium powder at 800 to 1100° C.

The present invention relates to a 3D-printed cobalt-based alloy product comprising carbon, tungsten and chromium with very good mechanical and thermal properties as well as a method of preparing the 3D-printed product and a powder alloy. The alloy has a high carbon content leading to high carbide content but small and evenly distributed carbides. A method facilitating 3D printing of high carbide content alloys such as the present alloy is also disclosed.

The present invention relates to a 3D-printed cobalt-based alloy product comprising carbon, tungsten and chromium with very good mechanical and thermal properties as well as a method of preparing the 3D-printed product and a powder alloy. The alloy has a high carbon content leading to high carbide content but small and evenly distributed carbides. A method facilitating 3D printing of high carbide content alloys such as the present alloy is also disclosed.