Provided is a method of producing spherical silver powder, which makes it possible to easily produce spherical silver powder having primary particle diameters with less variation than conventional powder and spherical silver powder obtained by the method. The method of producing spherical silver powder includes a reduction precipitation step of precipitating silver particles by reduction by adding a reductant including hydrazine carbonate to an aqueous reaction system containing silver ions.

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.

The present disclosure provides three-dimensional (3D) printing processes, apparatuses, software, and systems for the production of at least one desired 3D object. The 3D printer system (e.g., comprising a processing chamber, build module, or an unpacking station) described herein may retain a desired (e.g., inert) atmosphere around the material bed and/or 3D object at multiple 3D printing stages. The 3D printer described herein comprises one or more build modules that may have a controller separate from the controller of the processing chamber. The 3D printer described herein comprises a platform that may be automatically constructed. The invention(s) described herein may allow the 3D printing process to occur for a long time without operator intervention and/or down time.

A dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

A dust core including a metal magnetic powder and a resin, in which the metal magnetic powder shows a particle diameter of more than 0 μm and 200 μm or less, a number percentage of 5.0% or more of metal magnetic particles among the metal magnetic particles composing the metal magnetic powder are at least partially surface-coated with an inorganic compound including an alkaline earth metal, in a coating part coating the metal magnetic particles, an amount of the alkaline earth metal is 10.0 mass % or more, when a total amount of a metal element included in the coating part is 100 mass %, is provide. The dust core is superior in a corrosion-resistance.

The present invention provides a rare earth sintered magnet which contains R (R represents one or more rare earth elements essentially including Nd), T (T represents one or more iron group elements essentially including Fe), B, M.sup.1 (M.sup.1 represents one or more elements selected from among Al, Si, Cr, Mn, Cu, Zn, Ga, Ge, Mo, Sn, W, Pb and Bi) and M.sup.2 (M.sup.2 represents one or more elements selected from among Ti, V, Zr, Nb, Hf and Ta), while comprising an R.sub.2T.sub.14B phase as the main phase. This rare earth sintered magnet is characterized in that: the M.sup.1 is in an amount of from 0.5% by atom to 2% by atom; if (R), (T), (M.sup.2) and (B) are the respective atomic percentages of the above-described R, T, M.sup.2 and B, the relational expression (1) ((T)/14)+(M.sup.2)≤(B)≤((R)/2)+((M.sup.2)/2) is satisfied; and from 0.1% by volume to 10% by volume of all grain boundary phases in the magnet is composed of an R.sub.6T.sub.13M.sup.1 phase. This rare earth sintered magnet is able to achieve excellent magnetic characteristics including a good balance between high Br and high H.sub.cJ.

The present invention relates to an alloy with formula of RE-M-B—Fe as defined herein and oxygen content less than 0.9 wt %, wherein said RE is in the range of 29.0 weight % to 33.0 weight %; M is in the range of 0.25 weight % to 1.0 weight %; B is in the range of 0.8 weight % to 1.1 weight %; and Fe makes up the balance. The present invention also relates to a method for preparing a RE-M-Fe—B magnetic powder, as defined herein comprising the steps of: (a) melt spinning a RE-M-Fe—B alloy composition to obtain a melt-spun powder; (b) pressing the melt-spun powder of step (a) to obtain a compact body; (c) hot deforming the compact body of step (b) to obtain a die-upset magnet; (d) crushing the die-upset magnet of step (c) to obtain a powder; (e) milling and sieving the powder of step (d); and (f) passivating the powder of step (e) to obtain a magnetic powder; wherein: each of steps (d) to (f) is performed under a low oxygen environment and transfer between each of steps (d) to (f) is a sealed transfer; and wherein the oxygen content of the low oxygen environment and during each sealed transfer is below 0.5 weight %.

The present invention relates to an alloy with formula of RE-M-B—Fe as defined herein and oxygen content less than 0.9 wt %, wherein said RE is in the range of 29.0 weight % to 33.0 weight %; M is in the range of 0.25 weight % to 1.0 weight %; B is in the range of 0.8 weight % to 1.1 weight %; and Fe makes up the balance. The present invention also relates to a method for preparing a RE-M-Fe—B magnetic powder, as defined herein comprising the steps of: (a) melt spinning a RE-M-Fe—B alloy composition to obtain a melt-spun powder; (b) pressing the melt-spun powder of step (a) to obtain a compact body; (c) hot deforming the compact body of step (b) to obtain a die-upset magnet; (d) crushing the die-upset magnet of step (c) to obtain a powder; (e) milling and sieving the powder of step (d); and (f) passivating the powder of step (e) to obtain a magnetic powder; wherein: each of steps (d) to (f) is performed under a low oxygen environment and transfer between each of steps (d) to (f) is a sealed transfer; and wherein the oxygen content of the low oxygen environment and during each sealed transfer is below 0.5 weight %.

A tantalum powder, a tantalum powder compact, a tantalum powder sintered body, a tantalum anode, an electrolytic capacitor and a preparation method for tantalum powder. The tantalum powder contains boron element, and the tantalum powder has a specific surface area of greater than or equal to 4 m.sup.2/g; the ratio of the boron content of the tantalum powder to the specific surface area of the tantalum powder is 2˜16; the boron content is measured in weight ppm, and the specific surface area is measured in m.sup.2/g; Powder that can pass through a ρ-mesh screen in the tantalum powder accounts for over 85% of the total weight of the tantalum powder, where ρ=150˜170; and the tantalum powder with high CV has a low leakage current and dielectric loss, and good moldability.