Provided according to embodiments of the invention are varistor ceramic formulations that include zinc oxide (ZnO). In particular, varistor ceramic formulations of the invention may include dopants including an alkali metal compound, an alkaline earth compound, an oxide of boron, an oxide of aluminum, or a combination thereof. Varistor ceramic formulations may also include other metal oxides. Also provided according to embodiments of the invention are varistor ceramic materials formed by sintering a varistor ceramic formulation according to an embodiment of the invention. Further provided are varistors formed from such ceramic materials and methods of making such materials.

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 lithography based method for the manufacture of diamond composite materials in which green bodies are prepared by a layer-by-layer construction with resulting green bodies de-bound and sintered to achieve a dense high hardness material.

High-purity gallium nitride particles having a low oxygen content suitable for a raw material or a sintered body is provided. Gallium nitride particles characterized in that the oxygen content is 0.5 at % or less and the total impurity amount of elements, Si, Ge, Sn, Pb, Be, Mg, Ca, Sr, Ba, Zn and Cd, is less than 10 wtppm are used.

A cubic boron nitride sintered material comprises 30% by volume or more and 99.9% by volume or less of cubic boron nitride grains and 0.1% by volume or more and 70% by volume or less of a binder phase, the cubic boron nitride grain having a carbon content of 0.08% by mass or less, the cubic boron nitride sintered material being free of free carbon.

The present disclosure provides a transparent alumina-based plate, and a hot-pressing method to make the transparent alumina-based plate from platelet alumina. Alumina powder with a platelet morphology was hot-pressed to transparency with pre-load pressures of about 0-8 MPa, maximum temperatures of about 1750-1825° C., maximum pressures of about 2.5-80 MPa, and isothermal hold times of 1-7 hours. A novel alumina-based plate has been prepared, wherein the plate has a thickness of 2-5 mm, an in-line transmission of at least 60-75% for a light with a wavelength range of 645-2500 nm, an in-line transmission variance of <15% over the wavelength range of 645-2500 nm, and a relative density of 99.00-99.95%.

It is difficult for a Cr—Si-based sintered body composed of chromium silicide (CrSi.sub.2) and silicon (Si) to have high strength.

Provided is a Cr—Si-based sintered body including Cr (chromium) and silicon (Si), in which the crystal structure attributed by X-ray diffraction is composed of chromium silicide (CrSi.sub.2) and silicon (Si), a CrSi.sub.2 phase is present at 60 wt % or more in a bulk, a density of the sintered body is 95% or more, and an average grain size of the CrSi.sub.2 phase is 60 μm or less.

A sintered friction material, in which a content of a copper component is 0.5 mass % or less, is provided. The sintered friction material includes a titanate and a metal material other than copper, as a matrix. A content of the metal material other than copper is 10.0 volume % to 34.0 volume %. A method for manufacturing a sintered friction material is provided. The method includes a mixing step of mixing raw materials containing a titanate and a metal material other than copper, a molding step of molding the raw materials mixed in the mixing step, and a sintering step of sintering, at 900° C. to 1300° C., a molded product molded in the molding step. In the sintered friction material, the titanate and the metal material other than copper form a matrix, and a content of the metal material other than copper is 10.0 volume % to 34.0 volume %.

Provided according to embodiments of the invention are varistor ceramic formulations that include zinc oxide (ZnO). In particular, varistor ceramic formulations of the invention may include dopants including an alkali metal compound, an alkaline earth compound, an oxide of boron, an oxide of aluminum, or a combination thereof. Varistor ceramic formulations may also include other metal oxides. Also provided according to embodiments of the invention are varistor ceramic materials formed by sintering a varistor ceramic formulation according to an embodiment of the invention. Further provided are varistors formed from such ceramic materials and methods of making such materials.

A process for preparing a sintered silicon carbide body including sintering a sample including silicon carbide particles to form a shaped sintered silicon carbide body, the particles containing a silicon carbide core and a surface layer containing carbon and oxygen, the sample having at least 90 weight % being C or Si and having a carbon to silicon molar ratio molC/molSi higher than 1 and a carbon in excess to oxygen molar ratio Cex/molO which is higher than 0.5 and lower than 5.3.