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

A thermoelectric conversion material formed of a sintered body containing magnesium silicide as a main component contains 0.5 mass % or more and 10 mass % or less of aluminum oxide. The aluminum oxide is distributed at a crystal grain boundary of the magnesium silicide.

Polycrystalline cubic boron nitride compact include a body having sintered microcrystalline cubic boron nitride in a matrix of binder material. The microcrystalline cubic boron nitride particles have a size ranging from 2 microns to 50 microns. The particles of microcrystalline cubic boron nitride include a plurality of sub-grains, each sub-grain having a size ranging from 0.1 micron to 2 microns. The compacts are manufactured in a high pressure—high temperature (HPHT) sintering process. The compacts exhibit intergranular defect formation following introduction of wear. The sub-grains promote crack propagation based on micro-chipping rather than on a cleavage mechanism and, in sintered bodies, cracks propagate intergranularly rather than intragranularly, resulting in increased toughness and improved wear characteristics as compared to monocrystalline cubic boron nitride. The compacts are suitable for use as abrasive tools.

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.

There are provided a composite perovskite powder, a preparation method thereof, and a paste composition for an internal electrode having the same, the composite perovskite powder capable of preventing ions from being eluted from an aqueous system at the time of synthesis while being ultra-atomized, such that when the composite perovskite powder is used as an inhibitor powder for an internal electrode, sintering properties of the internal electrode may be deteriorated, and sintering properties of a dielectric material may be increased; accordingly, connectivity of the internal electrode may be improved, and permittivity and reliability of a multilayer ceramic capacitor (MLCC) may be increased.

A composite sintered material includes a plurality of diamond grains, a plurality of cubic boron nitride grains, and a remainder of a binder phase, wherein the binder phase includes cobalt, a content of the cubic boron nitride grains in the composite sintered material is more than or equal to 3 volume % and less than or equal to 40 volume %, and an average length of line segments extending across continuous cubic boron nitride grains in appropriately specified straight lines extending through the composite sintered material is less than or equal to a length three times as large as an average grain size of the cubic boron nitride grains.

The present application provides vanadium dioxide doped with Ti, or vanadium dioxide further doped with other atoms selected from the group of W, Ta, Mo, and Nb. The vanadium dioxide of the present application is excellent in moisture resistance and in which deterioration of endothermic characteristics due to moisture is suppressed.

Provided is a crystalline silicon carbide fiber containing silicon carbide, boron nitride, and zirconium carbide and having a content of Si of 64% by weight or more and a content of C of 28% by weight or more, in which the average particle size of SiC crystal grains is 100 nm or more.

A silicon-containing oxide-coated aluminum nitride particle including an aluminum nitride particle and a silicon-containing oxide coating covering the surface of the aluminum nitride particle. The content of carbon atoms is less than 1000 ppm by mass, and an Si/Al atom ratio of the surface as measured by AES analysis is 0.29 or more and 5.0 or less. In another aspect, the coverage of the silicon-containing oxide coating covering the surface of the aluminum nitride particle as measured by LEIS analysis is 15% or more and 100% or less.

A composite polycrystal contains polycrystalline diamond formed of diamond grains that are directly bonded mutually, and non-diamond carbon dispersed in the polycrystalline diamond, and has a concentration of contained hydrogen of greater than 1000 ppm and less than or equal to 20000 ppm.