Commissariat a L'energie Atomique

Rhone-poulenc Chimie

Marcel Boncoeur

Bernard Hansz

Louis Minjolle

Gilles Gasgnier

Jean-Francois Baumard

Bernard Rasneur

Marc Palacio

Thierry Lieven

Jean-Pierre Boilot

Francis Abraham

Francois Mandet

Frederic Valin

Olivier Renoult

Pierre Blouet

Jean-Claude Boivin

Nicole Roux

Jean-Claude Dubust

The invention relates to ceramic materials usable as tritium producing material in a thermonuclear fusion reactor. These materials are constituted by lithium zirconate substituted by copper in the form of solid solutions of the type Li.sub.2 ZrO.sub.3. Preferably, they comply with the formula: ##EQU1##

Copper-substituted, lithium zirconate-based ceramic usable as a tritium

This invention relates to a process for the preparation of lithium aluminosilicate or gamma lithium aluminate ceramics having a controlled microstructure and stoichiometry. According to this process, mixing takes place accompanied by stirring in a short chain anhydrous alcohol of an unpolymerized liquid aluminium alkoxide and optionally a silicon alkoxide with a hydrated or unhydrated lithium hydroxide, followed by the addition of water in order to hydrolyze the mixture and obtain, after drying, beta LiAlO.sub.2 powder. This powder can be directly compacted and then sintered at temperatures of 800.degree. to 1150.degree. C. without prior calcination giving a gamma lithium aluminate ceramic with a controlled stoichiometry and microstructure (grains of 0.1 to 10 .mu.m).

Process for the preparation of lithium aluminosilicate or gamma lithium

Ceramic compositions based on yttrium oxide contain a minor amount of a titanium oxide and are readily sintered into dense ceramic shaped articles well adopted for metallurgical applications.

Yttrium oxide/titanium oxide ceramic compositions

The present invention relates to a ceramic based on yttrium oxide and titanium oxide. This ceramic has a light transmission percentage of at least 20% in a wavelength range between 0.5 and 8 .mu.m. It also relates to a sintering process for obtaining said ceramic.

Transparent ceramics and production process for the same

A process for the production of, in particular, ceramic parts having a cavity by press molding or pressing sealed sheaths. The core used for defining the cavity and preventing subsequent machining operations is initially more voluminous than the desired cavity and has an adequate ductility to allow partial extrusion during pressing. This avoids often excessive mechanical stresses, which can lead to a bursting or shattering of the densified part when the sheath is removed. This process has, application to the hot isostatic pressing of fragile materials.

Process for the production of parts having a cavity by pressing

The invention relates to a process for shaping a material by isostatic compression at a temperature of at least 1300.degree. C. of a powder of said material in a tight sheath. The sheath is made from titanium or a titanium alloy and is internally coated with tantalum in such a way that the sheath can be embrittled during hot isostatic compression, by the diffusion of tantalum into the titanium or titanium alloy, in the presence of oxygen. In general, the titanium sheath is coated with tantalum by spraying in the presence of oxygen. The use of such a sheath makes it possible to avoid the operation of eliminating the sheath chemically or mechanically conventionally necessary in such processes.

Process for shaping a material by hot isostatic pressing and titanium

Surface treatment of a part and use of this treatment for improving the

Process and apparatus for confining the pollution of an isostatic pressing enclosure. At the end of an isostatic pressing operation, a glove box is sealingly fixed above the enclosure, the plug is removed from the latter and deposited within the glove box, after which the sampling and inspection operations necessary for detecting any contamination are performed. Application to the compression of radioactive waste by isostatic pressing.

Process and apparatus for confining the pollution of an isostatic

The invention relates to a process for the production of porous products of boron or boron compounds. This process comprises the following stages:

Process for the production of porous products made from boron or boron

The invention relates to a process and an apparatus for coating a member by plasma spraying. According to the invention, the pressure and composition of the atmosphere prevailing in the enclosure in which the operation takes place are constantly checked. The temperature of the member is regulated with the aid of a cooling system and the relative displacements of the member, the gun and the cooling system are automatically controlled. Application to the deposition of protective coatings on metal members or on composite materials.

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Paris, France

Marcel Boncoeur