A method for producing fine copper particles includes producing fine copper particles having a coating film containing cuprous oxide on a surface by heating copper or a copper compound in a reducing flame formed by a burner. The fine copper particles are produced by adjusting a mixing ratio between a combustible gas and a combustion supporting gas which form the reducing flame such that a volume ratio of CO/CO.sub.2 is in a range of 1.5 to 2.4.

A neodymium-iron-boron permanent magnet, a preparation method and use thereof are disclosed. The neodymium-iron-boron permanent magnet has a composition represented by formula I: [mHR(1−m) (Pr.sub.25Nd.sub.75)].sub.x(Fe.sub.100-a-b-c-dM.sub.aGa.sub.bIn.sub.cSn.sub.d).sub.100-x-yB.sub.y formula I; where a is 0.995-3.493, b is 0.114-0.375, c is 0.028-0.125, d is 0.022-0.100; x is 29.05-30.94, y is 0.866-1.000; m is 0.02-0.05; HR is Dy and/or Tb; M is at least one selected from the group consisting of Co, Cu, Ti, Al, Nb, Zr, Ni, W and Mo.

The embodiments disclosed herein are directed to systems and methods for manufacturing recycled copper alloy powder particles from used or deficient copper alloy powder particles. In some embodiments, used copper alloy powder particles comprising near-surface oxygen are introduced into a microwave plasma torch. In some embodiments, the used copper alloy powder particles are heated within the microwave plasma torch to at least partially remove the oxygen and form recycled copper alloy powder particles, without melting the used copper alloy powder particles.

A caster assembly configured to process and store a material includes a reaction chamber, a storage assembly configured to store material processed in the reaction chamber, and a blower configured to process and store the material. The reaction chamber includes a vessel configured to hold the material in a melted state prior to processing and a powder generating assembly configured to receive the material from the melting vessel. The powder generating assembly includes a feeding chamber and a feeding device disposed at least partially within the feeding chamber. The feeding device includes at least one nozzle configured to inject inert fluid, where the fluid is a gas, liquid, or combination of the two into the feeding chamber and a material inlet through which the material is configured to flow into the feeding chamber to be exposed to the inert fluid, where the fluid is a gas, liquid, or combination of the two.

A caster assembly configured to process and store a material includes a reaction chamber, a storage assembly configured to store material processed in the reaction chamber, and a blower configured to process and store the material. The reaction chamber includes a vessel configured to hold the material in a melted state prior to processing and a powder generating assembly configured to receive the material from the melting vessel. The powder generating assembly includes a feeding chamber and a feeding device disposed at least partially within the feeding chamber. The feeding device includes at least one nozzle configured to inject inert fluid, where the fluid is a gas, liquid, or combination of the two into the feeding chamber and a material inlet through which the material is configured to flow into the feeding chamber to be exposed to the inert fluid, where the fluid is a gas, liquid, or combination of the two.

A ratio of an angle of 2 to 15° is 50% or more in an arbitrary surface of the tungsten material, the angle being formed between a specific crystal orientation of a first crystal grain and a specific crystal orientation of a second crystal grain adjacent to the first crystal grain.

A ratio of an angle of 2 to 15° is 50% or more in an arbitrary surface of the tungsten material, the angle being formed between a specific crystal orientation of a first crystal grain and a specific crystal orientation of a second crystal grain adjacent to the first crystal grain.

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.

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.