The present disclosure relates to a magnesium-based raw material and a preparation method thereof. According to the technical solution, 40-60 wt % fused magnesia particles, 30-40 wt % fine monoclinic zirconia powder, 5-20 wt % fine zirconium oxychloride powder, 0.5-1.5 wt % calcium hydroxide nanopowder, 0.2-0.5 wt % calcium hydroxide nanopowder, and 0.1-0.3 wt % maleic acid are stirred for 15 min to mix well in a high-speed mixing mill at a constant temperature of 25° C. to obtain a mixed powder; and the mixed powder is mixed through a ball mill at a constant temperature of 25° C. for 3 min, roasted in a high temperature furnace at 250-400° C. for 0.5-3 h, and finally cooled to room temperature.

The present invention relates to parts of transparent corundum ceramics and the production and use of said parts.

A Li ion conductor having a composition different from a conventional composition is provided. The Li ion conductor contains at least one selected from a group Q consisting of Ga, V, and Al, Li, La and O. A part of an Li site is optionally substituted with a metal element D, a part of an La site is optionally substituted with a metal element E, and parts of Ga, V and Al sites are optionally substituted with a metal element J. A mole ratio of an amount of Li to a total amount of La, the element E, Ga, V, Al, and the element J is not lower than 8.1/5 and not higher than 9.5/5. A mole ratio of a total amount of Ga, V, and Al to a total amount of La and the element E is not lower than 1.1/3 and not higher than 2/3.

A dielectric substance includes a core-shell grain having a twin crystal structure. An interface of the twin crystal structure of the core-shell grain extends from a shell on one side, passes through a core, and extends to the shell on the other side.

Provided is an inorganic structure including a plurality of magnesium oxide particles; and a binding part that covers a surface of each of the magnesium oxide particles and binds the magnesium oxide particles together. The binding part contains an amorphous compound containing silicon, a metallic element other than silicon, and oxygen, and contains substantially no alkali metal, B, V, Te, P, Bi, Pb, and Zn. Also provided is a method for producing an inorganic structure including: a step for obtaining a mixture by mixing a plurality of magnesium oxide particles, a plurality of amorphous silicon dioxide particles, and an aqueous solution containing a metallic element other than silicon; and a step for pressurizing and heating the mixture under conditions of a pressure of 10 to 600 MPa and a temperature of 50 to 300° C.

The present invention concerns a process for the preparation of a porous carbon structure comprising the steps: a) providing a template comprising voids, b) filling of at least part of the voids with a precursor for the formation of the porous carbon structure, c) carbonizing the precursor for the formation of the porous carbon structure and d) removing at least part of the template. In preferred embodiments the precursor for the formation of the porous carbon structure is a formaldehyde-phenol resin, especially a cross-linked resorcinol-formaldehyde resin. The template further preferably comprises a block copolymer and an amphiphilic molecule, wherein the block copolymer comprises polymeric units of at least one lipophilic monomer and polymeric units of at least one hydrophilic monomer. Further preferred is a process wherein the template comprises a bimodal mixture of particles of silicon dioxide.

A method for making a fuel rod cladding tube and a cladding tube are described. The method includes wrapping ceramic fibers, for example, SiC fibers in a SiC matrix, around a tube formed from a metal alloy, such as a zirconium alloy. The interstices of the SiC wrappings on the tube are at least partially filled with SiC nano-sized particles. The surface of the filled tube is exposed by atomic layer deposition, at temperatures ranging from 25° C. to 600° C., to at least one cycle of alternating, non-overlapping pulses of gaseous precursors containing carbon and silicon to form a SiC monolayer. The step of filling the interstices of the SiC wrappings on the tube with SiC nano-sized particles fills large voids in the SiC wrapping. The step of exposing the surface of the particle filled SiC windings to at least one cycle of gaseous pulses fills small voids in the SiC wrapping.

A ZrO.sub.2—Al.sub.2O.sub.3-based ceramic sintered compact containing tetragonal ZrO.sub.2 particles having a crystallite size of from 5 to 20 nm as a main component and having an α-Al.sub.2O.sub.3 crystallite size of not greater than 75 nm and a relative density of not less than 99% can be produced by preparing a Y.sub.2O.sub.3 partially stabilized ZrO.sub.2—Al.sub.2O.sub.3-based powder having a molar ratio (mol %) of zirconia (ZrO.sub.2) and yttria (Y.sub.2O.sub.3) of from 96.5:3.5 to 97.5:2.5 and a mass ratio (mass %) of ZrO.sub.2 containing Y.sub.2O.sub.3 and alumina (Al.sub.2O.sub.3) of from 85:15 to 75:25, molding this powder by cold isostatic pressing, and then performing sintering to a high density by microwave sintering for 45 to 90 min in an inert gas atmosphere at 1200 to 1400° C. When performing microwave sintering, a heating rate is preferably from 5 to 20° C./min up to 600° C. and from 50 to 150° C./min at 600° C. or higher.

Methods for fabricating refractory metal scandate nanocomposite powders with homogeneous microstructured refractory metal grains and a uniform nanosized dispersion of scandia are provided. The powders prepared by the sol-gel methods have a spherical morphology, a narrow distribution of particle sizes and a very uniform dispersion of nanosized scandia particles joined to the tungsten grains. The powder particle sizes can range from nanometers to micrometers. The powders can be pressed into porous cathode structures that can be impregnated with emissive materials to produce high current density and long life cathodes for high-power terahertz vacuum electron devices. The sol-gel fabrication methods allow control over the materials, particle size, particle composition and pore size and distribution of the cathode structure by manipulation of the process parameters.

In some examples, a method including forming a layer of a slurry composition between a first ceramic or CMC part and a second ceramic or CMC part. The slurry composition includes a carrier material; and a plurality of solid particles in the carrier material. The plurality of solid particles includes first silicon carbide (SiC) particles defining a first average particle size, second SiC particles defining a second average particles size that is less than the first average particles size, and reactive additive particles. The method includes heating the layer of slurry composition to react the plurality of reactive additive particles to fuse the plurality of first SiC particles and the plurality of second SiC particles together with the reactive additive particles, wherein the fused layer of the slurry composition forms a joint layer that joins the first ceramic or CMC part to the second ceramic or CMC part.