The metal ceramic powder with a particle size of 15-45 .Math.m and suitable for thermal spraying is prepared through a combination of mechanical ball milling, spray granulation, and vacuum sintering. The metal ceramic powder is sprayed on a surface of a steel substrate adopting the high velocity oxygen fuel (HVOF) technology with oxygen-propane as fuel and taking oxygen as a combustion improver, propane as fuel, nitrogen as powder feeding carrier gas, and air as a cooling medium to prepare and form the NiCrBSi—ZrB2 composite coating. The present disclosure solves the problem that ZrB.sub.2 ceramic is difficult to compact during sintering and improves powder bonding strength and fluidity. The preparation method is simple, has advantages of high coating deposition efficiency and convenient equipment operation, and is cost-effective. The preparation method can improve thermal corrosion resistance and high-temperature wear resistance of a surface of boiler, and prolonging lifetime of the boiler.

A metal powder capable of producing a dust core having a high saturation magnetic flux density, excellent rust resistance, and a low iron loss. The metal powder includes from 1.0% to 15.0% of Si, from 1.0% to 13.0% of Cr, from 10 ppm to 10000 ppm of Cl, from 100 ppm to 10000 ppm of S (sulfur), and from 0.2% to 7.0% of O (oxygen) by mass concentration, the remainder including Fe and unavoidable impurities, in which the average particle diameter of the metal powder is from 0.1 μm to 2.0 μm. This facilitates the production of a dust core having a high magnetic flux density, excellent rust resistance, and a low iron loss.

A metal powder capable of producing a dust core having a high saturation magnetic flux density, excellent rust resistance, and a low iron loss. The metal powder includes from 1.0% to 15.0% of Si, from 1.0% to 13.0% of Cr, from 10 ppm to 10000 ppm of Cl, from 100 ppm to 10000 ppm of S (sulfur), and from 0.2% to 7.0% of O (oxygen) by mass concentration, the remainder including Fe and unavoidable impurities, in which the average particle diameter of the metal powder is from 0.1 μm to 2.0 μm. This facilitates the production of a dust core having a high magnetic flux density, excellent rust resistance, and a low iron loss.

Methods for large-scale additive manufacturing of high-strength boron nitride nanotubes (BNNT) / aluminum (Al) (e.g., reinforced Al alloy) metal matrix composites (MMCs) (BNNT/A1 MMCs), as well as the BNNT/A1 MMCs produced by the large-scale additive manufacturing methods, are provided. A combination of ultrasonication and spray drying techniques can produce good BNNT/Al alloy feedstock powders, which can be used in a cold spraying process.

Methods for large-scale additive manufacturing of high-strength boron nitride nanotubes (BNNT) / aluminum (Al) (e.g., reinforced Al alloy) metal matrix composites (MMCs) (BNNT/A1 MMCs), as well as the BNNT/A1 MMCs produced by the large-scale additive manufacturing methods, are provided. A combination of ultrasonication and spray drying techniques can produce good BNNT/Al alloy feedstock powders, which can be used in a cold spraying process.

Described herein are compositions, methods, and systems for printing metal three-dimensional objects. In an example, described is a composition for three-dimensional printing comprising: a metal powder build material, wherein the metal powder build material has an average particle size of from about 10 μm to about 250 μm; and a binder fluid comprising: an aqueous liquid vehicle, and latex polymer particles dispersed in the aqueous liquid vehicle, wherein the latex polymer particles have an average particle size of from about 10 nm to about 300 nm.

A method of manufacturing a modeled body includes: modeling including applying a modeling solution to each layer of powder laid in a layer, to solidify the powder to model a solidified object; sintering the solidified object to obtain a sintered body of the solidified object; and removing a sacrificial body from the sintered body, to obtain a modeled body. At the modeling, the modeling solution is applied to a modeled body area in the solidified object and a border area in the solidified object such that, after the modeling solution is applied, a density of the powder at the border area is smaller than a density of the powder in the modeled body area. The modeled body area corresponds to the modeled body. The border area corresponds to a border between the modeled body and the sacrificial body.

A composition suitable for 3D printing. The composition is in the form of a filament and includes: a) a metal and/or ceramic powder: b) an organic binding phase including two parts: b1) at least one thermoplastic compound selected from thermoplastic polymers and waxes; and b2) at least one volatile organic compound which has a vapor pressure at 50° C., ranging from more than 0 bar to 0.05 bar, wherein the amount of the at least one volatile organic compound ranges from more than 0.5% to 40% (v/v) by volume relative to the total volume of the composition.

A composition suitable for 3D printing. The composition is in the form of a filament and includes: a) a metal and/or ceramic powder: b) an organic binding phase including two parts: b1) at least one thermoplastic compound selected from thermoplastic polymers and waxes; and b2) at least one volatile organic compound which has a vapor pressure at 50° C., ranging from more than 0 bar to 0.05 bar, wherein the amount of the at least one volatile organic compound ranges from more than 0.5% to 40% (v/v) by volume relative to the total volume of the composition.

A composition suitable for 3D printing. The composition is in the form of a filament and includes: a) a metal and/or ceramic powder: b) an organic binding phase including two parts: b1) at least one thermoplastic compound selected from thermoplastic polymers and waxes; and b2) at least one volatile organic compound which has a vapor pressure at 50° C., ranging from more than 0 bar to 0.05 bar, wherein the amount of the at least one volatile organic compound ranges from more than 0.5% to 40% (v/v) by volume relative to the total volume of the composition.