A material for producing a three-dimensionally printed part including a metal material and at least one sintering aid in an amount effective to give the three-dimensionally printed part a density of between about 90% and about 100% after sintering is disclosed. A method of printing a three-dimensional part including selecting a metal material, incorporating at least one sintering aid into the metal material to form a print material, and printing the three-dimensional part is also disclosed. A method of producing a sintered metal part including providing a metal material for the sintered metal part incorporating boron as a first sintering aid, incorporating phosphorus as a second sintering aid, forming the metal part in a predetermined form the metal material, and heating the formed metal part to a sintering temperature is also disclosed. Three-dimensionally printed parts are also disclosed.

A material for producing a three-dimensionally printed part including a metal material and at least one sintering aid in an amount effective to give the three-dimensionally printed part a density of between about 90% and about 100% after sintering is disclosed. A method of printing a three-dimensional part including selecting a metal material, incorporating at least one sintering aid into the metal material to form a print material, and printing the three-dimensional part is also disclosed. A method of producing a sintered metal part including providing a metal material for the sintered metal part incorporating boron as a first sintering aid, incorporating phosphorus as a second sintering aid, forming the metal part in a predetermined form the metal material, and heating the formed metal part to a sintering temperature is also disclosed. Three-dimensionally printed parts are also disclosed.

The invention relates to the nuclear industry and can be used for producing fuel pellets from uranium-molybdenum metal powders enriched to 7% uranium 235 for nuclear reactor fuel elements. The pellets are sintered in an inert atmosphere of argon at a temperature ranging from 1100° C. to 1155° C., and the initial powder is a uranium-molybdenum powder having a fraction size of 160 .Math.m and a molybdenum con¬tent of 9.0 to 10.5 wt%. The powder is pre-heated at a temperature of 500° C. for 10-20 hours (in an atmosphere of argon) and is subsequently cold pressed into pellets in a die under a force of up to 950 MPa. In an alternative emb¬odiment for producing uranium-molybdenum pellets with a binder (plasticizer), the step of sintering is preceded by heating the pellets in an atmosphere of argon at 300° C. to 450° C. for 2-4 hours to remove the binder. The invention makes it possible to increase the uranium intensity of the fuel, reduce the amount of heat buildup in a reactor core, and lower the amount of energy released in the event of abnormalities in the operation of a nuclear reactor, thus providing increased reactor safety and resilience to accidents.

The present invention discloses a preparation process of multi-component spherical alloy powder, which adopts a plasma rotation electrode process (PREP) method to prepare the multi-component spherical alloy powder. The multi-component alloy includes at least one of refractory metals and compounds thereof, specifically including tungsten, molybdenum, tantalum, niobium, rhenium, tungsten carbide, tantalum carbide and the like.

The present invention adopts the PREP method to prepare the multi-component spherical alloy powder containing the refractory metals or compound thereof, and the prepared multi-component spherical alloy powder has high sphericity, good fluidity and high tap density, and is low in content of impurity elements and output of hollow powder and satellite powder; compared with other preparation methods, the prepared alloy powder has better performance and is an ideal material for metal 3D printing; and the present invention further solves the problem of difficulty in preparing a round rod with the refractory metals or compound thereof as a base material used in the PREP method, and provides a spatial structure meshing method, a direct element mixing method or a porous framework method to prepare a multi-component alloy rod.

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.

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.

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.

A method for laser additive manufacturing of a mechanical part includes providing a laser beam the operation of which will be controlled by a computer into which is introduced a CAD computer file which is cut into one or more strata which, once superimposed, allow to form the structure of the desired mechanical part, disposing a substrate in a manufacturing enclosure wherein an atmosphere of a neutral gas is created, depositing on the substrate at least a first layer of a powder of a first metallic material to be melted, levelling the first layer, subjecting by means of the laser beam the first layer to a selective melting step, if necessary, depositing on the substrate a second layer, levelling the second layer and subjecting this second layer to a step of selective melting, removing the excess material and cleaning the assembly and subjecting the part to finishing operations.