The present invention relates to a method for manufacturing a needle-shaped or rod-shaped porous iron powder. Specifically, the present invention provides a method for manufacturing a needle-shaped or rod-shaped porous iron and a needle-shaped or rod-shaped porous iron powder manufactured thereby, the method comprising the steps of: preparing a ferrous chloride dehydrate by concentrating a ferrous chloride aqueous solution; solid-liquid separating the ferrous dichloride to prepare ferrous chloride dehydrate powder; oxidizing the ferrous chloride dehydrate powder; and reducing the oxidized ferrous chloride powder.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900° C. to 1300° C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900° C. to 1300° C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.

Some variations provide a system for producing a functionalized powder, comprising: an agitated pressure vessel; first particles and second particles contained within the agitated pressure vessel; a fluid contained within the agitated pressure vessel; an exhaust line for releasing the fluid from the agitated pressure vessel; and a means for recovering a functionalized powder containing the second particles disposed onto surfaces of the first particles. A preferred fluid is carbon dioxide in liquefied or supercritical form. The carbon dioxide may be initially loaded into the pressure vessel as solid carbon dioxide. The pressure vessel may be batch or continuous and is operated under reaction conditions to functionalize the first particles with the second particles, thereby producing a functionalized powder, such as nanofunctionalized metal particles in which nanoparticles act as grain refiners for a component ultimately produced from the nanofunctionalized metal particles. Methods for making the functionalized powder are also disclosed.

An example of a method for making a build material composition for three-dimensional (3D) printing includes freezing a dispersion of flow additive nanoparticles in a liquid to form a frozen liquid containing the flow additive nanoparticles. The frozen liquid containing the flow additive nanoparticles is lyophilized to form flow additive agglomerates having a porous, fractal structure. The flow additive agglomerates are mixed with a host metal. The flow additive nanoparticles have an average flow additive particle size ranging from about 1 to about 3 orders of magnitude smaller than an average host metal particle size of the host metal.

An example of a method for making a build material composition for three-dimensional (3D) printing includes freezing a dispersion of flow additive nanoparticles in a liquid to form a frozen liquid containing the flow additive nanoparticles. The frozen liquid containing the flow additive nanoparticles is lyophilized to form flow additive agglomerates having a porous, fractal structure. The flow additive agglomerates are mixed with a host metal. The flow additive nanoparticles have an average flow additive particle size ranging from about 1 to about 3 orders of magnitude smaller than an average host metal particle size of the host metal.

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dx.sub.(200) of not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

A powder treatment assembly and method for treating a feedstock powder of feedstock particles includes directing the feedstock powder into a plasma chamber within a reactor, exposing the feedstock powder to a plasma field generated by a plasma source to form a treated powder having treated particles with an increased average sphericity relative to the feedstock particles, and supplying a hot gas sheath flow downstream of the plasma chamber, the hot gas sheath flow substantially surrounding the treated powder.

A powder treatment assembly and method for treating a feedstock powder of feedstock particles includes directing the feedstock powder into a plasma chamber within a reactor, exposing the feedstock powder to a plasma field generated by a plasma source to form a treated powder having treated particles with an increased average sphericity relative to the feedstock particles, and supplying a hot gas sheath flow downstream of the plasma chamber, the hot gas sheath flow substantially surrounding the treated powder.

There are provided reactive metal powder in-flight heat treatment processes. For example, such processes comprise providing a reactive metal powder; and contacting the reactive metal powder with at least one additive gas while carrying out said in-flight heat treatment process, thereby obtaining a raw reactive metal powder.