A production apparatus for fine particles includes a vacuum chamber, a material supply device, a plurality of electrodes arranged and a collection device connecting to the other end of the vacuum chamber and collecting fine particles, which generates plasma and produces fine particles from the material particles, in which a first electrode arrangement region on the material supply port's side and a second electrode arrangement region apart from the first electrode arrangement region to the collection device's side which respectively cross a direction in which the material flows between the vicinity of the material supply port and the collection device are provided in the intermediate part of the vacuum chamber, and both the first electrode arrangement region and the second electrode arrangement region are provided with a plurality of electrodes respectively to form the electrodes in multi-stages.

A needle array suitable for perforating a fibrous preform includes a backplate and a plurality of needles individually removably attached to and extending away from the backplate. Each of the plurality of needles includes a bundle of ceramic filaments, a metallic sheath surrounding a first end of the bundle abutting the backplate, and a sharpened point on the second end of the bundle, the second end being oppositely disposed from the first end.

Provided is a powder for shaping through irradiation with an energy beam, the powder including: a sublimable substance; and a sublimation suppression material, wherein the sublimation suppression material is an inorganic compound, and wherein particles of the sublimation suppression material adhere to part of surfaces of particles of the sublimable substance.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of L.sub.c>L.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is L.sub.c and the sintering shrinkage of the silicon carbide matrix is L.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

Methods of producing silicon carbide, and other metal carbide materials. The method comprises reacting a carbon material (e.g., fibers, or nanoparticles, such as powder, platelet, foam, nanofiber, nanorod, nanotube, whisker, graphene (e.g., graphite), fullerene, or hydrocarbon) and a metal or metal oxide source material (e.g., in gaseous form) in a reaction chamber at an elevated temperature ranging up to approximately 2400 C. or more, depending on the particular metal or metal oxide, and the desired metal carbide being produced. A partial pressure of oxygen in the reaction chamber is maintained at less than approximately 1.0110.sup.2 Pascal, and overall pressure is maintained at approximately 1 atm.

The present disclosure relates to a binder jet 3D process for preparing a ceramic part in which a binder composition is deposited on a powder material in a binder jet machine during which the binder in the binder composition comprises a preceramic polymer, and the binder impregnates particles of the powder.

A thermal spray powder includes composite powder particles that each have a silicon carbide core and a multi-layered shell that surrounds the core. The shell includes at least one layer of silica and at least one layer of alumina. The powder is used to deposit a mullite-based topcoat on a ceramic matrix composite wall of an article.

Currently, the commercial fuel of choice, UO.sub.2-zircaloy, is economical due to an established and simple fabrication process. However, the alternatives to the UO.sub.2-zircaloy that may improve on system safety are sought. The fully ceramic microencapsulated (FCM) fuel system that is potentially inherently safe fuel and is an improvement on the UO.sub.2-zircaloy system is prohibitively expensive because of the known methods to produce it. Disclosed herein is a new production route and fixturing that produces identical or superior FCM fuel consistent with mass production by providing a plurality of tristructural-isotropic fuel particles; mixing the plurality of tristructural-isotropic fuel particles with ceramic powder to form a mixture; placing the mixture in a die; and applying a current to the die so as to sinter the mixture by direct current sintering into a fuel element.

A method of preparing silicon carbide powder is provided, which includes mixing first silicon carbide powder with a liquid silicon carbide precursor, annealing the mixture at a first temperature and converting the silicon carbide precursor to a -phase silicon carbide particulate material, and annealing the material at a second temperature and grain-growing the first silicon carbide powder to second silicon carbide powder using the -phase silicon carbide particulate material.

The present invention provides a method for producing silicon carbide coated refractory grains comprising the following steps: a. Providing core refractory grains; b. Spraying an oxide sol onto said core refractory grains; c. Optionally mixing said core refractory grains with said oxide sol in a mixing device; d. Adding silicon carbide grains to said core refractory grains; and e. Mixing the mixture obtained in step d to obtain coated refractory grains having a core and a first silicon carbide coating layer.