A transparent complex oxide sintered body is manufactured by sintering a compact in an inert atmosphere or vacuum, and HIP treating the sintered compact, provided that the compact is molded from a source powder based on a rare earth oxide: (Tb.sub.xY.sub.1-x).sub.2O.sub.3 wherein 0.4≤x≤0.6, and the compact, when heated in air from room temperature at a heating rate of 15° C./min, exhibits a weight gain of at least y % due to oxidative reaction, y being determined by the formula: y=2x+0.3. The sintered body has a long luminescent lifetime as a result of controlling the valence of Tb ion.

A golden ceramic includes: a ceramic matrix in a weight percentage of 80-99% and a colorant in a weight percentage of 1-20%, wherein the ceramic matrix includes zirconium oxide and yttrium oxide, and the colorant includes zirconium nitride.

The present invention provides titanium nitride-reinforced zirconia toughened alumina (ZTA) ceramic powder and a preparation method thereof, and belongs to the technical field of ceramic materials. The preparation method provided in the present invention includes the following steps: mixing an aluminum salt, a zirconium salt, a yttrium salt, and a titanium salt with water to obtain a mixed aqueous solution, where the aluminum salt, the zirconium salt, the yttrium salt, and the titanium salt are water-soluble inorganic salts; mixing the obtained mixed aqueous solution and an alkaline precipitant for precipitation, to obtain hydroxide precipitate powder; successively conducting first calcination and second calcination on the obtained hydroxide precipitate powder, to obtain oxide solid solution powder; and subjecting the obtained oxide solid solution powder to selective nitridation reaction, to obtain titanium nitride-reinforced ZTA ceramic powder.

A ceramic composite sintered body, including: a metal oxide as a main phase, and silicon carbide as 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 an average crystal grain size of the silicon carbide dispersed at the crystal grain boundaries of the metal oxide is 0.30 μm or less.

A method of making a ceramic matrix composite (CMC) that may show improved resistance to chemical attack from molten silicon along with excellent mechanical strength is described. The method includes forming an interphase coating on one or more silicon carbide fibers, depositing a matrix layer comprising silicon carbide on the interphase coating, oxidizing the matrix layer to form an oxidized film comprising silicon oxide, depositing a wetting layer comprising silicon carbide on the oxidized film. After depositing the wetting layer, a fiber preform containing the silicon carbide fibers is heat treated. After the heat treatment, the fiber preform is infiltrated with a slurry. After infiltration with the slurry, the fiber preform is infiltrated with a melt containing silicon, and then the melt is cooled to form a ceramic matrix composite.

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/μm.sup.2.

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 method of depositing silicon carbide on a preform to form a ceramic matrix composite comprises placing the preform into a reaction vessel, removing air from the reaction vessel and backfilling the reaction vessel with an inert gas to an operating pressure. The reaction vessel and the preform are heated to an operating temperature. A carrier gas and precursor materials are heated to a preheat temperature outside of the reaction vessel. The carrier gas and the precursor materials are introduced to the reaction vessel in a specified ratio. Off gasses, the precursor materials that are unspent, and the carrier gas are removed from the reaction vessel to maintain the specified ratio of the precursor materials in the reaction vessel.

A W.sub.18O.sub.49 peak is confirmed by X-ray diffraction analysis of a sputtering surface and a cross section orthogonal to the sputtering surface, a ratio I.sub.S(103)/I.sub.S(010) of a diffraction intensity I.sub.S(103) of a (103) plane to a diffraction intensity I.sub.S(010) of a (010) plane of W.sub.18O.sub.49 of the sputtering surface is 0.57 or more, a ratio I.sub.C(103)/I.sub.C(010) of a diffraction intensity I.sub.C(103) of the (103) plane to a diffraction intensity I.sub.C(010) of the (010) plane of W.sub.18O.sub.49 of the cross section is 0.38 or less, and an area ratio of the W.sub.18O.sub.49 phase of a surface parallel to the sputtering surface is 37% or more.

A process for the manufacture of a refractory block including more than 80% zirconia, in percentage by weight based on the oxides. The process includes the following successive stages: melting, under reducing conditions, of a charge including more than 50% zircon, in percentage by weight, such as to reduce the zircon and obtain a molten material, application of oxidizing conditions to the molten material, casting of the molten material, and cooling until at least partial solidification of the molten material in the form of a block. Also, the process can include heat treatment of the block.