A method for producing a metal-ceramic substrate with at least one electrically conductive via, in which one metal layer, respectively, is attached in a planar manner to a ceramic plate or a ceramic layer to each of two opposing surface sides of the ceramic layer is provided. The method includes introducing a metal-containing, powdery and/or liquid substance into a hole in the ceramic layer delimiting the via prior to the attachment of both metal layers, or subsequent to the attachment of one of the two metal layers to form an assembly. Prior to the attachment of the other one of the two metal layers, and the assembly is subjected to a high-temperature step above 500 C. in which the metal-containing substance wets the ceramic layer at least partially with a wetting angle of less than 90.

A MgF.sub.2 system fluoride sintered body for a radiation moderator having a compact polycrystalline structure excellent in radiation moderation performance, especially neutron moderation performance, contains CaF.sub.2 of 90% by weight at the maximum and has a relative density of 95.2% or more.

Scintillator materials based on mixed garnet compositions, as well as corresponding methods and systems, are described.

A method for producing a transparent polycrystalline ceramic includes forming at least one planar transparent region near a surface within the ceramic, wherein the at least one planar transparent region has a lower thermal expansion coefficient than other regions of the ceramic. The method further includes generating compressive stresses in the at least one planar transparent region near the surface after a thermal treatment and cooling.

The present invention provides a welding tool member for friction stir welding comprising a silicon nitride sintered body, wherein the silicon nitride sintered body includes an additive component other than silicon nitride in a content of 15% by mass or less, and the additive component includes three or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. It is preferable that the content of the additive component is 3% by mass or more and 12.5% by mass or less. It is also preferable that the additive component includes four or more elements selected from Y, Al, Mg, Si, Ti, Hf, Mo and C. Due to above structure, there can be provided a welding tool member for friction stir welding having a high durability.

An electrically conductive, oxidic target material includes a proportion of substoichiometric molybdenum oxide phases of at least 60% by volume, an MoO.sub.2 phase in a proportion of 2-20% by volume, and optionally an MoO.sub.3 phase in a proportion of 0-20% by volume. The substoichiometric molybdenum oxide phase proportion is formed by one or more substoichiometric MoO.sub.3-y phase(s), where y is in each case in a range from 0.05 to 0.25. A process for producing the target material and a process for using the target material are also provided.

The invention relates to a grain for production of a refractory product, to the use of such grains, to a refractory product, to a process for producing a refractory product and to a refractory product produced thereby.

There is provided a platy zinc oxide sintered compact containing 0.80 wt % or less at least one first dopant element selected from the group consisting of Al, Ga and In, the balance consisting essentially of ZnO and optionally at least one second dopant element selected from the group consisting of Br, Cl, F, Sn, Y, Pr, Ge, B, Sc, Si, Ti, Zr, Hf, Mn, Ta, W, Cu, Ni, Cr, La, Gd, Bi, Ce, Sr and Ba, the second dopant element being optional component, wherein the (002)-plane orientation in the plate surface is 60% or more. The zinc oxide sintered compact of the present invention has excellent properties such as high orientation in addition to transparency and conductivity.

A method for producing a transparent alumina sintered body according to the present invention includes (a) a step of preparing an alumina raw material powder containing a plate-like alumina powder having an aspect ratio of 3 or more and a fine alumina powder having an average particle diameter smaller than that of the plate-like alumina powder so that, when a mixing ratio of the plate-like alumina powder to the fine alumina powder in terms of mass ratio is assumed to be T:(100T), T is 0.001 or more and less than 1, and so that a mass ratio R1 of F relative to Al in the alumina raw material powder is less than 15 ppm; (b) a step of forming a raw material for forming containing the alumina raw material powder into a compact; and (c) a step of sintering the compact so as to obtain a transparent alumina sintered body.

Provided is a ceramic substrate. The ceramic substrate includes a core layer, made of zirconia toughened alumina; and surface layers, symmetrically located on an upper and a lower surfaces of the core layer, made of Al.sub.2O.sub.3. The core layer has a chemical composition of 0 wt %<ZrO.sub.240 wt % and 60 wt %Al.sub.2O.sub.3<100 wt %. A method for manufacturing the ceramic substrate and a power module including the ceramic substrate are also provided.