A porous alpha-alumina catalyst support is prepared by (i) preparing a precursor material comprising a boehmitic-derived alumina having a pore volume of at least 0.6 mL/g, wherein the boehmitic-derived alumina is obtained by thermal decomposition of a boehmitic starting material and the boehmitic starting material consists predominantly of block-shaped crystals, and optionally an inorganic bond material; (ii) forming the precursor material into shaped bodies; (iii) calcining the shaped bodies to obtain the porous alpha-alumina catalyst support. The support structure has a high overall pore volume, while keeping its surface area sufficiently large so as to provide optimal dispersion of catalytically active species, in particular metal species. The support is useful for a catalyst for producing ethylene oxide by gas-phase oxidation of ethylene.

A silicon carbide flow reactor fluidic module comprises a monolithic closed-porosity silicon carbide body and a tortuous fluid passage extending through the silicon carbide body, the tortuous fluid passage lying within two or more layers with the silicon carbide body, the tortuous passage having an interior surface, the interior surface having a surface roughness of less than 10 μm Ra. A method of forming the fluidic module is also disclosed.

A method for manufacturing an electrostatic chuck with multiple chucking electrodes made of ceramic pieces using metallic aluminum as the joining. The aluminum may be placed between two pieces and the assembly may be heated in the range of 770 C to 1200 C. The joining atmosphere may be non-oxygenated. After joining the exclusions in the electrode pattern may be machined by also machining through one of the plate layers. The machined exclusion slots may then be filled with epoxy or other material. An electrostatic chuck or other structure manufactured according to such methods.

A method for manufacturing a ceramic substrate that includes preparing a plurality of ceramic green sheets, at least one of the plurality of ceramic green sheets having a disappearance material that disappears by firing in a recessed portion formation planned region of the at least one of the plurality of ceramic green sheets; forming a mother multilayer body by laminating the plurality of ceramic green sheets such that the at least the one ceramic green sheet having the disappearance material is positioned on an uppermost layer of the mother multilayer body; and forming a recessed portion in the mother multilayer body before firing by pressing the recessed portion formation planned region of the mother multilayer body.

A gas nozzle according to the present disclosure includes a supply hole having a tubular shape and configured to guide a gas and an injection hole connecting to the supply hole. The gas nozzle configured to inject the gas from the injection hole is made from ceramics or single crystal including an oxide, a fluoride, or an oxyfluoride of a rare earth element or an yttrium aluminum composite oxide as a primary component. An arithmetic mean roughness Ra of an inner circumferential surface forming the supply hole is smaller on an outflow side than on an inflow side of the gas.

The present invention relates to sintered platelet-like randomly shaped abrasive particles based on alpha alumina having a hardness H.sub.V of at least 20 GPa and a crystal structure with an average crystal size between 100 nm and 300 nm, whereby the abrasive particles comprise a body having a first surface and a second surface opposite to the first surface, both surfaces are separated from each other by a randomly shaped sidewall having a thickness (T) between 20 μm and 500 μm.

The present disclosure relates to a method for preparing high-temperature superconducting yttrium barium copper oxide (YBCO) wire by 3D-printing, this method is divided into the following four steps: firstly, preparing a nano-level superconducting powder precursor; and then, preparing a printing paste with suitable viscosity and supporting characteristics; after that, using a CAD 3D modeling, exporting STL format model data and slicing by a professional software; implementing one-step preparing strands with low AC loss by twisting the print nozzle. Finally, the printed twisted wire is formed into a practical superconducting twisted cable through the processes such as plastic removal process, crystallizing process, oxygen supplementing process and assembling process in order. The present disclosure firstly provides an application for applying high temperature superconducting material to direct ink writing 3D-printing technology. By preparing micro/nano level superconducting core filaments based on 3D-printing, the diameter of the core filaments could be reduced, and thereby a material-structure integrative design could be implemented. The present disclosure simplifies the preparation of high temperature superconducting wires, improves the current-carrying capacity and the production efficiency of the high temperature super conducting wires, and reduces the production cost.

A heater includes a base body, a resistance heating element, and a terminal part. The base body is made of ceramic and is a plate shape. The resistance heating element is located inside the base body. The terminal part is electrically connected to the internal conductor, is located inside the base body in at least a part, and is exposed from a lower surface of the base body to an exterior of the base body. The base body includes a hole opened at the lower surface of the base body. The terminal part includes a connection conductor. The connection conductor is inserted in the hole and is connected to the internal conductor. A lower surface of the connection conductor is located on a side closer to the upper surface of the base body other than the lower surface of the base body. The hole includes a reduced-diameter portion which has a diameter smaller than a diameter of the connection conductor between the lower surface of the connection conductor and the lower surface of the base body.

A ceramic containing, in mass %: Si.sub.3N.sub.4: 20.0 to 60.0%, ZrO.sub.2: 25.0 to 70.0%, at least one selected from SiC and AlN: 2.0 to 17.0%, where AlN is 10.0% or less, at least one selected from MgO, Y.sub.2O.sub.3, CeO.sub.2, CaO, HfO.sub.2, TiO.sub.2, Al.sub.2O.sub.3, SiO.sub.2, MoO.sub.3, CrO, CoO, ZnO, Ga.sub.2O.sub.3, Ta.sub.2O.sub.5, NiO and V.sub.2O.sub.5: 5.0 to 15.0%, wherein Fn calculated from the following equation (1) satisfies 0.02 to 0.40. This ceramic can be laser machined with high efficiency.

Fn=(SiC+3AlN)/(Si.sub.3N.sub.4+ZrO.sub.2)  (1)

Method for manufacturing a CMC, i.e. ceramic matrix composite material, part provided with at least one cutout, as well as to such a CMC part provided with at least one cutout, the method comprising the following steps: providing (E1) a fibrous reinforcement (10), forming (E2′) a cavity in a portion of the fibrous reinforcement (10), injecting (E3) a slip comprising at least a ceramic powder and a solvent, the slip being injected so as to impregnate the fibrous reinforcement (10′) and to fill the cavity of the fibrous reinforcement (10′), drying (E4) the obtained assembly, carrying out a densification (E6) by infiltration of a liquid densification material and solidification of said densification material, machining (E7) at least one cutout in the obtained blank (30) within the volume corresponding to the cavity of the fibrous reinforcement (10).