A composite sintered body, wherein the composite sintered body consists of ceramic composite sintered body, the ceramic composite sintered body comprises aluminum oxide as a main phase, and silicon carbide as a sub-phase, in which the composite sintered body has mullite in crystal grains of the aluminum oxide.

To provide a dielectric porcelain composition and an electronic component that demonstrate ferroelectricity. A dielectric porcelain composition that is characterized by having a perovskite-type oxynitride as a principal component and by including a polycrystalline body that demonstrates ferroelectricity.

The present invention relates to a negative active material for a lithium secondary battery, a preparation method therefor, and a lithium secondary battery including the same. The negative electrode active material is a negative electrode material for a secondary battery, the negative electrode active material comprising a silicon-carbon composite comprising: a core comprising crystalline carbon and silicon particles; and an amorphous carbon-containing coating layer disposed on a surface of the core, wherein the negative electrode active material comprises: silicon oxide formed on a surface of the silicon particles; and an oxide of crystalline carbon, formed on a surface of the crystalline carbon, the average particle diameter (D50) of the silicon particles having a nanometer size, the proportion of O relative to Si in the silicon oxide is 30%-50%, and the proportion of O relative to C in the oxide of the crystalline carbon is 4%-10%.

The invention relates to a method for producing three-dimensional objects, in particular workpieces, made from silicon-carbide containing compounds, in particular material, by means of additive manufacturing.

A ceramic and a method of forming a ceramic including milling steel slag exhibiting a diameter of 5 mm of less to form powder, sieving the powder to retain the powder having a particle size in the range of 20 to 400 removing free iron from the powder with a magnet, heat treating the powder at a temperature in the range of 700 C. to 1200 C. for a time period in the range of 1 hour to 10 hours and oxidizing retained iron in the powder, compacting the powder at a compression pressure in the range of 20 MPa to 300 MPA, and sintering the powder at a temperature in the range of 700 C. to 1400 C. for a time period in the range of 0.5 hours to 4 hours to provide a ceramic.

A composite sintered body is a ceramic composite sintered body which includes metal oxide which is a main phase, and silicon carbide which is a sub-phase, in which crystal grains of the silicon carbide are dispersed in crystal grains of the metal oxide and at crystal grain boundaries of the metal oxide, and a proportion of the crystal grains of the silicon carbide dispersed in the crystal grains of the metal oxide is 25% or more in an area ratio with respect to a total crystal grains of the silicon carbide.

The present invention provides a sintered body containing W and WC, having excellent hardness, strength, compactness, and corrosion resistance, without containing W.sub.2C, and capable of being used for the purpose of a cutting tool or a glass molding die, or a seal ring. There is provided a sintered body containing 4 to 50 vol % of tungsten metal as binder phases, 50 to 95 vol % of tungsten carbide (WC), and 0.5 to 5.0 vol % of tungsten oxide (WO.sub.2), in which the tungsten oxide (WO.sub.2) has an average grain size of 5 nm to 150 nm and is present in a sintered body structure at an average density of 5 to 20 particles/m.sup.2.

Non-oxidative direct methane conversion (NDMC) to value-added products, such as H.sub.2, C.sub.2 hydrocarbons, and aromatics, occurs within a reactor heated to an elevated temperature. The reactor can have a first volume, where a feed gas including methane is provided, separated from a second volume, where a sweep gas is provided, by a dense thin film membrane supported on a porous wall. The thin film membrane is a mixed ionic-electronic permeable membrane that allows H2 generated in the first volume to be transported to the second volume for removal by (or reaction with) the sweep gas. A catalyst can be provided in or adjacent to the first volume. For example, the catalyst can be a metal doped quartz material (e.g., Fe(c)SiO.sub.2) or a metal/zeolite material (e.g., Mo/ZSM5). Methane conversion and/or product selectivity in the reactor can be manipulated by control of gas flow rates, reaction temperatures, and/or feed and sweep gas compositions.

Shaped gel articles that are formed within a mold cavity and that retain the size and shape of the mold cavity upon removal from the mold cavity, sintered articles prepared from the shaped gel articles, and methods of making the sintered articles are provided. The shaped gel articles are formed from a casting sol that contains colloidal silica particles that are treated with a surface modification composition that includes a silane surface modification agent having a radically polymerizable group. The sintered article has a shape identical to the mold cavity (except in regions where the mold cavity was overfilled) and to the shaped gel article but reduced in size proportional to the amount of isotropic shrinkage.

Aluminum nitride crystal particles, aluminum nitride powders containing the same, production processes for both of them, an organic polymer composition comprising the aluminum nitride crystal particles and a sintered body. Each of the aluminum nitride crystal particles has a flat octahedral shape in a direction where hexagonal faces are opposed to each other, which is composed of two opposed hexagonal faces and 6 rectangular faces, in which the average distance D between two opposed corners of each of the hexagonal faces is 3 to 110 m, the length L of the short side of each of the rectangular faces is 2 to 45 m, and L/D is 0.05 to 0.8; each of the hexagonal faces and each of the rectangular faces cross each other to form a curve without forming a single ridge; and the true destiny is 3.20 to 3.26 g/cm.sup.3.