A ceramic powder for a ceramic component, in particular based on zirconia and/or alumina, in particular for a timepiece or jewelry piece. The powder includes at least one noble metal among platinum, rhodium, osmium, palladium, ruthenium and iridium, at a quantity of less than or equal to 5% by weight.

Provided are pre-sintered and sintered zirconia dental ceramic materials. The materials have a gradient in yttria content. The materials may have a gradient in one or more physical/mechanical property and/or one or more optical property. The materials may be made by mixing at least two zirconia ceramic powders having different yttria content. A sintered zirconia dental ceramic material may be in the form of a dental article.

A method may produce a ceramic part with a mother-of-pearl effect, in particular for watchmaking. Such methods may include: forming a ceramic body; depositing a layer of an oxy-nitride component of the OxNy type on at least a portion of the ceramic body; and oxidizing at least a portion of the oxy-nitride layer, preferably by heating.

A method may produce a ceramic part with a mother-of-pearl effect, in particular for watchmaking. Such methods may include: forming a ceramic body; depositing a layer of an oxy-nitride component of the OxNy type on at least a portion of the ceramic body; and oxidizing at least a portion of the oxy-nitride layer, preferably by heating.

A force-transmitting assembly includes a metal shaft having at least two longitudinally-extending grooves defined in an outer surface, and a metal hub having at least two longitudinally-extending grooves defined in an inner surface that surrounds the outer surface of the shaft. A plurality of discrete parts is disposed in the at least two longitudinally-extending grooves of the shaft and the hub in an interference-fit manner so as to transmit a torque from the shaft to the hub. Each of the discrete parts is composed of at least 50 mass % of technical ceramic selected from Si.sub.3N.sub.4, SiAlON, Al.sub.2O.sub.3, ZrO.sub.2, or a mixture of two or more of Si.sub.3N.sub.4, SiAlON, Al.sub.2O.sub.3, and ZrO.sub.2.

A force-transmitting assembly includes a metal shaft having at least two longitudinally-extending grooves defined in an outer surface, and a metal hub having at least two longitudinally-extending grooves defined in an inner surface that surrounds the outer surface of the shaft. A plurality of discrete parts is disposed in the at least two longitudinally-extending grooves of the shaft and the hub in an interference-fit manner so as to transmit a torque from the shaft to the hub. Each of the discrete parts is composed of at least 50 mass % of technical ceramic selected from Si.sub.3N.sub.4, SiAlON, Al.sub.2O.sub.3, ZrO.sub.2, or a mixture of two or more of Si.sub.3N.sub.4, SiAlON, Al.sub.2O.sub.3, and ZrO.sub.2.

A method for enhancing optical properties of sintered, zirconia ceramic bodies and zirconia ceramic dental restorations is provided. The porous or pre-sintered stage of a ceramic body is treated with an yttrium-containing composition and sintered, resulting in sintered ceramic bodies having enhanced optical properties. The enhanced optical properties may be substantially permanent, remaining for the useful life of the sintered ceramic body.

A method for enhancing optical properties of sintered, zirconia ceramic bodies and zirconia ceramic dental restorations is provided. The porous or pre-sintered stage of a ceramic body is treated with an yttrium-containing composition and sintered, resulting in sintered ceramic bodies having enhanced optical properties. The enhanced optical properties may be substantially permanent, remaining for the useful life of the sintered ceramic body.

A refractory article including a body having central opening extending through at least a portion of the body, the central opening having a receiving surface having a convex curvature. In an embodiment, the body can include a coupling protrusion extending from a portion of an upper surface of the body and a coupling depression on a portion of a bottom surface of the body.

[Problem]

A technique for improving translucency in order to prepare a zirconia sintered body having high translucency without using special equipment, has been required.

[Solution]

To provide A sintering method for a dental zirconia calcined body containing 5.5 mol % to 7.0 mol % of a stabilizer, wherein the method satisfies the following (a) to (c). (a) an average rate of temperature increase in the section from room temperature to 1300° C. is 9° C./min or more. (b) an average rate of temperature increase in the section from 1300° C. to 1400° C. is 0.6° C./min or more and 3° C./min or less. (c) an average rate of temperature increase in the section from 1400° C. to the maximum temperature of the sintering process is 0.5° C./min or more and 2.5° C./min or less.