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 method for the production of a superconducting wire (20) uses a monofilament (1) having a powder core (3) that contains at least Sn and Cu, an inner tube (2), made of Nb or an alloy containing Nb, that encloses the powder core (3), and an outer tube (4) in which the inner tube (2) is arranged. The outer side of the inner tube (2) is in contact with the inner side of the outer tube (4) and the outer tube (4) is produced from Nb or from an alloy containing Nb. The outer tube is disposed in a cladding tube. The superconducting current carrying capacity of the superconducting wire is thereby improved.

The present disclosure discloses a nano-lanthanum oxide reinforced tungsten-based composite material and a preparation method thereof. A pure tungsten powder and a nano-lanthanum oxide powder are mixed to obtain a mixed powder, and in the mixed powder, the nano-lanthanum oxide powder accounts for 0.5-2% of the mixed powder by mass percent; and then, 3D printing forming is conducted on the mixed powder to obtain a bulk material of the nano-lanthanum oxide reinforced tungsten-based composite material. The nano-lanthanum oxide reinforced tungsten-based composite material of the present disclosure has excellent mechanical properties.

A method of forming an article includes producing a base powder including a plurality of base particles. Each base particle includes an external surface and a first material. The method further includes removing one or more oxides from the external surface of each base particle to form a cleaned powder including a plurality of cleaned particles. Each cleaned particle includes a cleaned external surface made of the first material. The method further includes coating the cleaned external surface of each cleaned particle with a second material having a greater oxidation resistance than the first material to form a coated powder including a plurality of coated particles. Each coated particle includes an external layer including the second material that fully covers the cleaned external surface made of the first material. The method further includes forming the article using the coated powder.

A method of forming a projectile for use in a firearm ammunition cartridge, the method including mixing a first material and a second material having different densities to produce a core mixture, disposing the core mixture in a die, heating the core mixture to the melting point, removing the core mixture from the die, quenching the core mixture, and plating the core mixture with a jacket material.

This disclosure relates a polycrystalline cubic boron nitride, PCBN, composite material for use in friction stir welding. The PCBN composite material comprises tungsten (W), rhenium (Re) and aluminium (Al) in the binder matrix material.

In various embodiments, wire composed at least partially of arc-melted refractory metal material is utilized to fabricate three-dimensional parts by additive manufacturing.

A preparation method for a W—Cu composite plate with a Cu phase in finger-shaped gradient distribution is provided. The method includes adding WO.sub.X powder obtained with ammonium metatungstate as a raw material into W powder through a combustion synthesis method, adding a binder and a pore-forming agent to prepare a slurry, then performing tape casting, soaking in water and sintering to obtain a W framework with pores in finger-shaped distribution, and then infiltrating Cu to obtain a target product. The Cu phase in the W—Cu composite material prepared by the present method is distributed in a finger-shaped gradient manner from an infiltration surface to the interior of a specimen, the Cu phase and the W phase are mutually pinned, and the W—Cu interface has good bonding strength. The present method has the characteristics of adjustable material component performance, simple process, low cost, suitability for large-scale production and the like.

A tungsten-base alloy material and a preparation method therefor. The preparation method comprises: 1) evenly grinding composite powder containing tungsten and zirconium oxide, and then performing annealing treatment at 700-1000° C. to obtain powder A; and 2) grinding and then compression moulding the powder A, and then performing liquid-phase sintering to obtain a tungsten-base alloy blank so as to obtain the tungsten-base alloy material.

In a method for producing nanoparticles of copper selenide, a flowable copper precursor is formed by combining a copper starting material and a ligand, and a flowable selenium precursor is formed by suspending a selenium starting material in a liquid. Then a flowable copper-selenium mixture including a lower-polarity solvent is formed by combining the flowable copper precursor and the flowable selenium precursor. The flowable copper-selenium mixture is conducted through at least one heating unit, and the nanoparticles of copper selenide are isolated in an oxygen-depleted environment. The isolation includes combining a solution containing the nanoparticles of copper selenide and a deoxygenated, higher-polarity solvent to precipitate the nanoparticles.