A cordierite-based sintered body according to the present invention contains cordierite as a main component and silicon nitride or silicon carbide. The cordierite-based sintered body preferably has a thermal expansion coefficient less than 2.4 ppm/° C. at 40° C. to 400° C., an open porosity of 0.5% or less, and an average grain size of 1 μm or less.

An electro-conductive B.sub.4C—TiB.sub.2 has a microstructure in which large B.sub.4C grains are coated by small TiB.sub.2 grains. The composite ceramic includes 10˜30% by volume of TiB.sub.2. A method for preparing the electro-conductive B.sub.4C—TiB.sub.2 composite ceramic includes: (1) weighing B.sub.4C, TiC, and amorphous B powder; (2) mixing evenly and drying thoroughly the powders; and (3) loading the mixed powder into a graphite mold; and placing the graphite mold in a spark plasma sintering furnace for sintering under vacuum, where the sintering is performed at 2000° C. and 50 MPa for 5˜20 min.

To a co-precipitating aqueous solution, aqueous solutions containing (a) Tb ions, (b) at least one other rare earth ions selected from the group consisting of Y ions and lanthanoid rare earth ions (excluding Tb ions), (c) Al ions and (d) Sc ions are added; the resulting solution is stirred at a liquid temperature of 50° C. or less to induce a co-precipitate of the components (a), (b), (c) and (d); the co-precipitate is filtered, heated and dehydrated; and the co-precipitate is fired thereafter at from 1,000° C. to 1,300° C., thereby forming a sinterable garnet-type complex oxide powder.

A composition which can be photopolymerized to make a part consisting of an oxide ceramic, or a hybrid part comprising at least one oxide ceramic and organic constituents, by a stereolithographic technique, the composition comprising: at least one photopolymerizable organic compound; at least one photo-initiator; at least one precursor of the oxide ceramic wherein the composition comprises from 25% to 70% by mass, relative to the total mass of the composition, of the at least one precursor of the oxide ceramic; and wherein the at least one precursor of the oxide ceramic comprises a mixture comprising a nanometric powder of the oxide ceramic, and at least one other element selected from a micrometric powder of the oxide ceramic and a pre-ceramic compound of the oxide ceramic.

A slurry or slip composed of a dispersion medium and a dispersoid including sinterable raw material powder containing a complex oxide powder represented by the following formula (1):
(Tb.sub.1-x-yR.sub.xSc.sub.y).sub.3(Al.sub.1-zSc.sub.z).sub.5O.sub.12  (1)
wherein R is yttrium and/or lutetium, 0.05≤x<0.45, 0<y<0.1, 0.5<1-x-y<0.95, and 0.004<z<0.2 is prepared; the slurry or slip is subsequently enclosed in a mold container to be subjected to solid-liquid separation by centrifugal casting to mold a cast compact; the cast compact is dried thereafter; a dried compact is degreased; a degreased compact is sintered thereafter; and a sintered body is further subjected to a hot isostatic pressing treatment to obtain the transparent ceramic material composed of the sintered body of garnet-type rare earth complex oxide represented by the formula (1).

A composite ceramic including: a lithium garnet major phase; and a grain growth inhibitor minor phase, as defined herein. Also disclosed is a method of making composite ceramic, pellets and tapes thereof, a solid electrolyte, and an electrochemical device including the solid electrolyte, as defined herein.

An electro-conductive B.sub.4C—TiB.sub.2 has a microstructure in which large B.sub.4C grains are coated by small TiB.sub.2 grains. The composite ceramic includes 10˜30% by volume of TiB.sub.2. A method for preparing the electro-conductive B.sub.4C—TiB.sub.2 composite ceramic includes: (1) weighing B.sub.4C, TiC, and amorphous B powder; (2) mixing evenly and drying thoroughly the powders; and (3) loading the mixed powder into a graphite mold; and placing the graphite mold in a spark plasma sintering furnace for sintering under vacuum, where the sintering is performed at 2000° C. and 50 MPa for 5˜20 min.

A composite ceramic including: a lithium garnet major phase; and a grain growth inhibitor minor phase, as defined herein. Also disclosed is a method of making composite ceramic, pellets and tapes thereof, a solid electrolyte, and an electrochemical device including the solid electrolyte, as defined herein.

A method for producing a granular material from sintered magnesia by sintering of pressed articles, in particular pellets, from MgO powder, preferably from caustic MgO powder, and subsequent mechanical comminution of the pressed articles, the sintering being carried out in such a way that the granular material has a grain porosity (total porosity), according to DIN EN 993-1:1195-04 and DIN EN 993-18:1999-01, of from 15 to 38 vol %, preferably 20 to 38 vol %. Also, a batch for producing a coarse ceramic, refractory, shaped or unshaped product containing the porous sintered magnesia, to such a product produced from the batch and to a method for its production, to a lining, in particular a working casing and/or a backing, of a large-volume industrial furnace, the lining, in particular the working casing and/or the backing, having at least one such product, as well as to such an industrial furnace.

A nanocomposite optical ceramic (NCOC) material. The material having a first solid phase, a second solid phase, and a third solid phase. The first solid phase has first solid phase grains no larger than 5 μm, and each first solid phase grain has a first solid phase grain boundary. The second solid phase has second solid phase grains no larger than 5 μm, and each second solid phase grain has a second solid phase grain boundary. The third solid phase has a doping agent. The doping agent is less than 5 atomic % soluble in the first solid phase and the second solid phase. At least part of the third solid phase is situated at the second solid phase grain boundary.