A sintered body, containing zinc, magnesium and oxygen as constituent elements, wherein the atomic ratio of zinc to the sum of zinc and magnesium [Zn/(Zn+Mg)] is 0.20 to 0.75, the atomic ratio of magnesium to the sum of zinc and magnesium [Mg/(Zn+Mg)] is 0.25 to 0.80, and the sintered body consists of a single crystal structure as measured by X-ray diffraction.

An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al.sub.2O.sub.3 and a component represented by A.sub.3B.sub.5O.sub.12:Ce; and each of A and B in A.sub.3B.sub.5O.sub.12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 μm or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.

The invention relates to a blank from a ceramic material, wherein at least two layers of ceramic material of different compositions are filled into a die layer-by-layer and after filling of the layers they are then pressed and sintered, wherein after filling of a first layer this is structured on its surface in such a way that the first layer, viewed across its surface, differs in its height from region to region, and then a layer with a composition that differs from the first layer is filled as a second layer into the mold.

A ceramic body is provided that is suitable for use in dental applications to provide a natural aesthetic appearance. A colorized ceramic body is formed that has at least one color region and a color gradient region. A ceramic body is formed having at least two color regions and a color gradient that forms a transition region between two color regions. A method for making the colorized ceramic body includes unidirectional infiltration of a coloring composition into the ceramic body.

The invention relates to an item made of a material consisting of a plurality of ceramic phases, said material including: a majority ceramic phase comprising nitrides and/or carbonitrides of one or more element(s) selected from among Ti, Zr, Hf, V, Nb, and Ta, said majority ceramic phase being present in a percentage by weight comprised between 60 and 98%, at least one minority ceramic phase, with either one single minority ceramic phase formed of zirconium and/or aluminium silicide, or several minority ceramic phases formed respectively of carbides of one or more element(s) selected from among Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W and of zirconium oxides and/or aluminium oxides, said at least one minority ceramic phase being present in its entirety in a percentage by weight comprised between 2 and 40%.

The present invention also relates to the method for manufacturing this item.

The present invention relates to a green body, a pre-ceramic body and a ceramic body based on metal oxide particles, in particular zirconium oxide. The present invention also relates to the method of producing said materials and to the use thereof, in particular in the field of dentistry.

A process for making a sintered article including the steps of: (a) preparing a particulate mixture; (b) contacting the particulate mixture to water to form a humidified mixture; (c) pressing the humidified mixture to form a green article; (d) optionally, subjecting the green article to an initial drying step; (e) subjecting the green article to a firing step in a kiln to form a hot fused article; and (f) cooling the hot fused article to form a sintered article. The particulate mixture includes: (i) at least 20 wt % coarse coal combustion fly ash; and (ii) at least 30 wt % clay, wherein the coarse coal combustion fly ash has a particle size in the range of from greater than 150 μm to less than 250 μm.

Provided is a dielectric for an electrostatic chuck, which is capable of ensuring sufficient hardness, while ensuring basic properties, such as intrinsic volume resistivity, required for a dielectric for a Johnson-Rahbek type electrostatic chuck. The dielectric has a main crystal phase consisting of corundum, wherein the dielectric includes Al.sub.5BO.sub.9 as another crystal phase, and wherein a ratio I.sub.A/I.sub.B, where I.sub.A denotes a (021) peak intensity of Al.sub.5BO.sub.9 as measured by powder X-ray diffraction, and I.sub.B denotes a (012) peak intensity of corundum as measured by powder X-ray diffraction, is in the range of 0.04 to 0.4.

The present invention provides a zirconia pre-sintered body that develops the preferable shade with a short firing time. The present invention relates to a zirconia pre-sintered body comprising zirconia that comprises predominantly monoclinic, and a stabilizer capable of inhibiting a phase transformation of zirconia, the zirconia pre-sintered body satisfying the following conditions: L1, a1, b1, L2, a2, and b2 are confined within predetermined ranges, L1>L2, a1<a2, and b1<b2,
where (L1,a1,b1) represent values of (L*,a*,b*) of the L*a*b* color system after sintering as measured at a first point falling within an interval of a length from one end of the zirconia pre-sintered body to 25% of the entire length of a straight line extending along a first direction from one end to the other end of the zirconia pre-sintered body, and (L2,a2,b2) represent values of (L*,a*,b*) after sintering as measured at a second point falling within an interval of a length from the other end of the zirconia pre-sintered body to 25% of the entire length of the straight line, and the values of (L*,a*,b*) after sintering show unchanging patterns of increase and decrease in a direction from the first point to the second point.

The invention relates to a process for the production of a dental restoration, in which an oxide ceramic material (a) is subjected to a first heat treatment, (b) is subjected to a second heat treatment and (c) is cooled,
wherein the heat treatment in step (a) is effected at lower pressure than the heat treatment in step (b).