A power-module substrate and a heat sink made of an aluminum-impregnated silicon carbide formed by impregnating aluminum in a porous body made of silicon carbide; where yield strength of a circuit layer is σ1 (MPa), a thickness of the circuit layer is t1 (mm), a bonding area of the circuit layer and a ceramic board is A1 (mm.sup.2), yield strength of a metal layer is σ2 (MPa), a thickness of the metal layer is t2 (mm), a bonding area of the metal layer and the ceramic board is A2 (mm.sup.2); the thickness t1 is formed to be between 0.1 mm and 3.0 mm (inclusive); the thickness t2 is formed to be between 0.15 mm and 5.0 mm (inclusive); the thickness t2 is formed larger than the thickness t1; and a ratio {(σ2×t2×A2)/(σ1×t1×A1)} is in a range between 1.5 and 15 (inclusive).

The invention relates to multi-layer oxide ceramic bodies and in particular to presintered multi-layer oxide ceramic blanks and oxide ceramic green bodies suitable for dental applications. These bodies can be thermally densified by further sintering without distortion and are thus particularly suitable for the manufacture of dental restorations. The invention also relates to a process for the manufacture of such multi-layer oxide ceramic bodies as well as to a process for the manufacture of dental restorations using the multi-layer oxide ceramic bodies.

A zirconia sintered body is provided in which the strength between layers of powders is improved. A flexural strength of a test sample of the zirconia sintered body, measured pursuant to JISR1601, is not less than 1000 MPa. The test sample is formed by preparing a plurality of zirconia powders, each containing zirconia and preferably yttria as a stabilizer that suppresses phase transition of zirconia, the zirconia powders differing in a composition, layering the zirconia powders to form a zirconia composition, and sintering the zirconia composition to form a zirconia sintered body. The flexural strength is measured such that a load point is positioned at a boundary of the zirconia powders, the boundary traversing the test sample of the sintered body along a direction of load application.

A zirconia pre-sintered body suitable for dental milling, grinding and/or cutting can provide a sintered body in which the strength between layers of powders is improved. A flexural strength of a test sample of the zirconia sintered body, measured pursuant to JISR1601, is preferably not less than 1000 or 1100 MPa.

A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a layer of joining material between the two pieces. The wetting and flow of the joining material is controlled by the selection of the joining material, the joining temperature, the joining atmosphere, and other factors. The ceramic pieces may be on a non-diffusable type, such as aluminum nitride, alumina, beryllium oxide, and zirconia, and the pieces may be brazed with an aluminum alloy under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck.

A sensor element includes a ceramic layered body having a zirconia layer part and two alumina layer parts provided on both surfaces of the zirconia layer part, respectively, and a plurality of electrodes provided in the ceramic layered body. At least one of the two alumina layer parts contains Ti element, the zirconia layer part has a layer containing Zr element and Ti element in the vicinity of an interface with the at least one alumina layer part, and the layer contains Ti element in an amount from 0.05 to 5.0 mass %.

A sensor element (10) having a laminate structure, and extending in an axial direction AX, the sensor element including a first and second ceramic layers (118B, 115) disposed apart from each other in a laminating direction; a third ceramic layer (118) intervening between the first and second ceramic layers in the laminating direction and having a hollow space (10G) formed therein; and an internal space which is the hollow space surrounded by the first ceramic layer, the second ceramic layer, and the third ceramic layer, wherein, at a periphery (10f) of the internal space, a fourth ceramic layer (181) containing as a main component a ceramic material different from that contained as a main component in the first and third ceramic layers intervenes between the first ceramic layer and the third ceramic layer which are exposed to the internal space. Also disclosed is a method for manufacturing the gas sensor element.

A ceramic capacitor includes a multilayer structure, wherein a main component of dielectric layers is ceramic expressed by a general formula A.sub.mBO.sub.3 (0.995m1.010), wherein the dielectric layers include a rare earth element Re as a first sub-component by 2.0 mol to 5.0 mol when converted into Re.sub.2O.sub.3/2, include Mg as a second sub-component by 1.0 mol to 3.0 mol when converted into MgO, include V as a third sub-component by 0.05 mol to 0.25 mol when converted into V.sub.2O.sub.5/2, include Si as a fourth sub-component by 0.5 mol to 5.0 mol when converted into SiO.sub.2, include an alkali earth metal element M as a fifth sub-component by 0.1 mol to 5.0 mol when converted into MCO.sub.3, on a presumption that an amount of the ceramic is 100 mol, wherein a ratio Si/V is 30 or less.

The present invention relates to a method of forming a 3D ceramic structure by adding a 3D structure with one or more layer(s) of ceramic mixture onto a ceramic substrate. The present invention also relates to a 3D ceramic structure as well as to a green 3D ceramic structure.

A composite includes a component and a glass or glass ceramic material. The component has a first coefficient of expansion .sub.1 and the glass or the glass ceramic material has a second coefficient of expansion .sub.2. The glass or the glass ceramic material has a surface with a thickness and thickness differences (TTV) within the surface, and thickness fluctuations (LTV). The composite has a residual stress in the glass or the glass ceramic material (WARP), and a geometric and material-physical degree of compatibility KG4.