Methods of producing a ceramic article include heating the ceramic green body containing a quantity of one or more organic materials to extract only a fraction of the organic materials from the ceramic green body by exposing the ceramic green body to a process atmosphere which is heated to a hold temperature of from 225° C. to about 400° C. and has from 2% to 7% O.sub.2 by volume of the process atmosphere. The method further includes cooling the ceramic green body to a temperature of below 200° C., exposing the ceramic green body to a higher concentration of O.sub.2 than in the process atmosphere of the heating step, and firing the ceramic green body to form the ceramic article. Volatile extraction units for implementing the methods are also described.

An aluminum nitride sintered body with improved mechanical strength without compromised thermal dissipating properties. The aluminum nitride sintered body contains 100 parts by weight of AlN, 3 to 20 parts by weight on an oxide basis of at least one type of nitride selected from the group consisting of Zr and Ti as an additive, and 1 to 10 parts by weight of Y.sub.2O.sub.3 as a sintering aid. The oxygen content in the sintered body is 1.8 wt % or less, and the thermal conductivity is 130 W/m.Math.K or higher.

An aluminum nitride sintered body with improved mechanical strength without compromised thermal dissipating properties. The aluminum nitride sintered body contains 100 parts by weight of AlN, 3 to 20 parts by weight on an oxide basis of at least one type of nitride selected from the group consisting of Zr and Ti as an additive, and 1 to 10 parts by weight of Y.sub.2O.sub.3 as a sintering aid. The oxygen content in the sintered body is 1.8 wt % or less, and the thermal conductivity is 130 W/m.Math.K or higher.

A binder for an injection moulding composition including: from 40 to 55 volume percent of a polymeric base, from 35 to 45 volume percent of a mixture of waxes or a mixture of wax and palm oil, and at least 5 volume percent of at least one surfactant, wherein the polymeric base is formed of copolymers of ethylene and methacrylic or acrylic acid, copolymers of ethylene and propylene and/or maleic anhydride-grafted polypropylene, and polymers soluble in isopropyl alcohol, propyl alcohol and/or turpentine, and chosen from the group including a cellulose acetate butyrate, a polyvinyl butyral and a copolyamide, the respective quantities of the binder components being such that their sum is equal to 100 volume percent of the binder.

A fuel cell system component ink includes a fuel cell system component powder, a solvent including propylene carbonate (PC), and a binder including polypropylene carbonate (PPC).

A composition which can be photopolymerized to make a part consisting of an oxide ceramic, or a hybrid part comprising at least one oxide ceramic and organic constituents, by a stereolithographic technique, the composition comprising: at least one photopolymerizable organic compound; at least one photo-initiator; at least one precursor of the oxide ceramic wherein the composition comprises from 25% to 70% by mass, relative to the total mass of the composition, of the at least one precursor of the oxide ceramic; and wherein the at least one precursor of the oxide ceramic comprises a mixture comprising a nanometric powder of the oxide ceramic, and at least one other element selected from a micrometric powder of the oxide ceramic and a pre-ceramic compound of the oxide ceramic.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

The present invention relates to a method for preparing a fully ceramic capsulated nuclear fuel material containing three-layer-structured isotropic nuclear fuel particles coated with a ceramic having a composition which has a higher shrinkage than a matrix in order to prevent cracking of ceramic nuclear fuel, wherein the three-layer-structured nuclear fuel particles before coating is included in the range of between 5 and 40 fractions by volume based on after sintering. More specifically, the present invention provides a composition for preparing a fully ceramic capsulated nuclear fuel containing three-layer-structured isotropic particles coated with the substance which includes, as a main ingredient, a silicon carbine derived from a precursor of the silicon carbide wherein a condition of ΔL.sub.c>ΔL.sub.m at normal pressure sintering is created, where the sintering shrinkage of the coating layer of the three-layer-structured isotropic nuclear fuel particles is ΔL.sub.c and the sintering shrinkage of the silicon carbide matrix is ΔL.sub.m; material produced therefrom; and a method for manufacturing the material. The residual porosity of the fully ceramic capsulated nuclear fuel material is 4% or less.

A process for producing a process for producing a LnM.sub.2Cu.sub.3O.sub.x high-temperature superconductive powder, the process comprising: i) providing an aqueous solution of Ln, M and Cu and at least one mineral acid; ii) adding at least one sequestrating agent and, optionally, at least one dispersant to the solution to form a precipitate; iii) recovering the precipitate from the solution; and iv) heating the precipitate in a flow of oxygen to form the LnM.sub.2Cu.sub.3O.sub.x powder, wherein Ln is a rare earth element, preferably Y, Ce, Dy, Er, Gd, La, Nd, Pr, Sm, Sc, Yb, or a mixture of two or more thereof, and wherein M is selected from Ca, Sr, and Ba.

The invention relates to a porous zirconia article in particular for use in the dental or orthodontic field, the porous zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the porous zirconia article being characterized by a BET surface from 15 to 100 m.sup.2/g. The invention also relates to a sintered zirconia article in particular for use in the dental or orthodontic field, the sintered zirconia article comprising ZrO.sub.2: 80 to 87 wt. %, Y.sub.2O.sub.3: 3 to 5 wt. %, Al.sub.2O.sub.3: 10 to 14 wt. %, wt. % with respect to the weight of the porous zirconia article, the sintered zirconia article being characterized by a corundum crystal phase content of 7 to 12 wt. % and a flexural strength of at least 2,000 MPa.