A method to form a machinable ceramic matrix composite comprises forming a porous ceramic multilayer on a surface of a fiber preform. In one example, the porous ceramic multilayer comprises a gradient in porosity in a direction normal to the surface. In another example, the porous ceramic multilayer includes low-wettability particles having a high contact angle with molten silicon, where an amount of the low-wettability particles in the porous ceramic multilayer varies in a direction normal to the surface. After forming the porous ceramic multilayer, the fiber preform is infiltrated with a melt, and the melt is cooled to form a ceramic matrix composite with a surface coating thereon. An outer portion of the surface coating is more readily machinable than an inner portion of the surface coating. The outer portion of the surface coating is machined to form a ceramic matrix composite having a machined surface with a predetermined surface finish and/or dimensional tolerance.

A method of forming a ceramic matrix composite component according to an exemplary embodiment of this disclosure, among other possible things includes laying up plies of ceramic reinforcement material with sacrificial plies to form a preform, infiltrating the preform with a ceramic matrix material, and machining away the sacrificial plies to reveal a surface profile of the ceramic matrix composite component. A preform for a ceramic matrix composite component is also disclosed.

A ceramic green sheet including a plurality of substrate forming regions. A barcode or a two-dimensional code is drawn in a portion of the ceramic green sheet. The barcode or the two-dimensional code is obtained by encoding one or more of the following information. Information relating to raw materials used when the ceramic green sheet is produced, information relating to molding conditions of the ceramic green sheet, information relating to a release agent used when a plurality of the ceramic green sheets are stacked, or a serial number.

An ultra-low thermal mass refractory article includes fibers impregnated with a colloidal inorganic oxide. The refractory article has at least one of the following properties: (i) a density of 500 kg/m.sup.3 to 1500 kg/m.sup.3; (ii) a thermal conductivity of 1.0 Wm/K or less at 700° C.; and/or (iii) a linear thermal shrinkage at 1400° C. of less than 2.5%.

The invention relates to a process of producing a dental zirconia article, the process comprising the step of sintering a porous dental zirconia article, the sintering comprising a heat-treatment segment A characterized by a heating rate of at least 3 K/sec up to a temperature of at least 1,200° C., the porous dental zirconia article being composed of a zirconia material containing 6.0 to 8.0 wt. % yttria, 0.05 to 0.12 wt. % alumina and comprising a coloring component containing Tb, the porous dental zirconia article being essentially free of Fe components. The invention also relates to a process comprising the additional step of applying a glazing composition to the outer surface of the porous zirconia article before the heat-treatment or sintering is conducted.

The present invention discloses a multiphase ceramic material with a giant dielectric constant, wherein the multiphase ceramic material has a general formula of A.sub.xB.sub.nxTi.sub.1−(n+1)xO.sub.2; wherein A is at least one selected from the group consisting of Nb, Ta, V, Mo, and Sb, B is at least one selected from the group consisting of In, Ga, Al, Co, Cr, Sc, Fe (III), and a trivalent rare-earth cation; n is a molar ratio of B to A, 1<n≤5 , 0<x≤0.1. The multiphase ceramic material possesses outstanding properties including a giant dielectric constant, a low dielectric loss, and excellent frequency- and temperature-stability. In particular, it exhibits a high insulation resistivity of higher than 10.sup.11 Ω.Math.cm and a high breakdown voltage, which implies it can be applied in high-energy storage devices and supercapacitors. This invention also provides a method to synthesize the multiphase ceramic material.

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 zirconia sintered body comprises zirconia and multiple different areas, including at least one upper area and at least one lower area having a different chemical composition and a different strength. The sintered body has a translucency and a strength with an inverse relationship. The translucency increases in one direction across the multiple different areas and the strength decreasing in the same direction across the multiple different areas. At least part of the sintered body has a total light transmittance of at least 35% and less than 53% to light with a wavelength at least at a point between 400 nm and 600 nm, and at least 51% and less than 57% to light with a wavelength at least at a point between 600 nm and 800 nm, at a thickness of 0.6 mm. At least a part of the sintered body has a strength of at least 925 Mpa.

A high-strength zirconia-alumina composite ceramic substrate suitable for semiconductor devices has been invented. It is manufactured by a procedure starting with mixing powder formula of alumina, zirconia, and a self-made synthetic additive for ball milling in an organic solvent at room temperature. The resulting mixture is homogenously dispersed and is then subjected to the steps of slurry preparation, degassing, green embryo forming, punching, calculation, and sintering to yield the final composite ceramic substrate with an excellent mechanical property of three-point bending strength>600 MPa and superior thermoelectric properties of thermal conductivity>26 W/mK, insulation resistance>10.sup.14 Ω.Math.cm and surface leakage current (150° C.)<200 nA.

The present disclosure relates to the field of dental material treatment, and particularly to a dental zirconia treatment technology. The specific technical solution is as follows: a zirconia treatment method, mainly involving color masking the zirconia, surface roughening the zirconia, coloring the zirconia, surface protection treatment and additional protective film treatment. Based on this treatment method, a brand-new color masking liquid, coloring liquid and adhesive solution are proposed. The present zirconia treatment technology not only meets the individualized requirements of patients for teeth, but also meets the requirements of dentists for convenient operation, so that it is of great value in application and popularization on the market.