An alumina sintered body having a low dielectric loss tangent and a method for manufacturing the alumina sintered body are provided. An alumina sintered body contains Al.sub.2O.sub.3 99.50 mass % or more, and 99.95 mass % or less and sodium and silicon, wherein at a surface layer A in any given cross-section and a central portion B of the cross-section in a depth direction from the surface layer A, a concentration ratio of sodium to silicon in the surface layer A is smaller than the concentration ratio of sodium to silicon at the central portion B.

The invention relates to a method for producing a part, comprising the production of successive solid metallic layers (201 . . . 20n), each layer being produced by depositing a metal (25) called filler metal, said filler metal consisting of an aluminium alloy comprising at least the following alloying elements: Zr, in a mass fraction of 0.60 to 1.40%, Mn, in a mass fraction of 2.00 to 5.00%, Ni, in a mass fraction of 1.00 to 5.00%, Cu, in a mass fraction of 1.00 to 5.00%.

The invention also relates to a part obtained by means of the method.

The alloy used in the additive manufacturing method of the invention makes it possible to obtain parts with exceptional properties.

The invention relates to a method for producing a part, comprising the production of successive solid metallic layers (201...20n), each layer being produced by depositing a metal (25) called filler metal, said method being characterized in that the part has a specific grain structure.

The invention also relates to a part obtained by means of this method and an alternative method.

The alloy used in the additive manufacturing method of the invention makes it possible to obtain parts with exceptional properties.

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.

A metal component is disclosed. The metal component has a first dimension greater than 5 mm, and a second dimension greater than 5 mm. The metal component may include where the alloy includes titanium, aluminum, vanadium, carbon, nitrogen, and oxygen. The alloy may include zirconium, titanium, copper, nickel, and beryllium. The metal component is not die-cast, melt-spun, or forged. An ejector and a method for jetting the metal component is also disclosed.

Methods and systems are described for fabricating a component using 3D printing. A 3D printed piece is created including a body of the component, a support structure, and a first sacrificial interface region coupling the body of the component to the support structure. The body of the component is formed of a first metal or ceramic material and the first sacrificial interface region is formed at least partially of a second metal or ceramic material. The body of the component is then separated from the support structure by applying a chemical or electrochemical dissolution process to the 3D printed piece. Because the second metal or ceramic material is less resistant to the dissolution process than the first metal or ceramic material, the first sacrificial interface region at least partially dissolves, thereby separating the body of the metal component from the support structure, without dissolving the body of the component.

A method for heat treating metal alloy powder includes (a) introducing metal alloy powder to a chamber having a floor and a sidewall; (b) flowing a fluidizing gas through the floor and into the chamber to fluidize the metal alloy powder in the chamber; (c) flowing an additional gas through the sidewall into the chamber; and (d) heating the chamber to heat treat the metal alloy powder in the chamber. A system for heat treating metal alloy powder includes an inner chamber having a porous floor and a porous sidewall; an outer chamber, the inner chamber being inside of the outer chamber and defining an annular space between the outer chamber and the inner chamber, wherein the outer chamber and the inner chamber are inside a furnace; a source of fluidizing gas connected to the porous floor through the annular space; and a source of additional gas communicated with the porous sidewall through the annular space.

A method for preparing a rare earth aluminum alloy powder applicable for additive manufacturing includes: heating and melting aluminum ingots into an aluminum melt; adding required alloy elements to the aluminum melt to obtain an alloy melt in which the alloy elements are present in the following preset percentages by weight: 1.00% to 10.00% of Ce, 0.05% to 8.00% of Mg, 0.10% to 7.50% of Y, 0.10% to 2.50% of Zr, less than 0.1% of impurities, and the balance aluminum; leading out the alloy melt through a fluid guiding pipe, and impacting the alloy melt with a high-pressure gas flow so that the alloy melt is atomized into fine droplets under an action of surface tension, and solidified into spherical alloy powder; and collecting the spherical alloy powder in a vacuum collector, and screening and drying the spherical alloy powder to obtain the rare earth aluminum alloy powder.

The present invention provides: an aluminum alloy member which can be manufactured at a relatively low cost and has a light weight, and which can have high dimensional accuracy under a high-temperature environment and is less likely to undergo the color-fading of a blackened surface even under a high-temperature environment, and has excellent heat resistance; and a method for manufacturing the aluminum alloy member with high efficiency. The aluminum alloy member according to the present invention comprises: a substrate which comprises an extruded material of an aluminum powder alloy having an Si content of 20 to 40% by mass and has an anodic oxide coating film formed on the surface thereof, and an electrolytically colored layer which is formed by precipitating a metal or a metal salt on voids in the anodic oxide coating film.

A three-dimensional (3D) metal object manufacturing apparatus is equipped with a liquid silicate application system to apply liquid silicate to a surface of a build platform prior to manufacture of a metal object. The liquid silicate layer is permitted to air dry and then the platform is heated to its operational temperature range for formation of a metal object with melted metal drops ejected by the apparatus. The liquid silicate layer forms a glassy, brittle layer on which the metal object is formed. This brittle layer is removed relatively easily with the object after the object is manufactured and the build platform is permitted to cool. The silicate layer improves the wetting of the surfaces of build platforms made with non-wetting materials, such as oxidized steel, while also preventing metal-to-metal welds with wetting materials, such as tungsten or nickel.