Abstract: A filter for the filtration of a fluid, such as a liquid, includes or composed of a support element made of a porous ceramic material, the element having a tubular or parallelepipedal shape delimited by an external surface and including, in its internal portion, a set of adjacent channels with axes parallel to one another and separated from one another by walls of the porous inorganic material, wherein at least a portion of the channels and/or at least a portion of the external surface are covered with a porous separating membrane layer, wherein the layer is made of a material essentially composed of sintered grains of silicon carbide (SiC), and the weight content of elemental oxygen of the layer is less than 0.5%.

Abstract: Method for manufacturing porous products consisting essentially of titanium suboxide(s) of general formula TiOx, the value of x being between 1.6 and 1.9, the method including a) mixing the raw materials including at least one source of titanium dioxide, a reducing agent comprising carbon, b) forming the product, c) optionally, in particular when organic products are used during step a), thermal treatment under air or an oxidizing atmosphere, d) sintering, for example at a temperature above 1150° C. but not exceeding 1430° C., under a neutral or reducing atmosphere, in which the source of titanium dioxide consists of at least 55 wt % of anatase.

Abstract: Method for manufacturing porous products consisting essentially of titanium suboxide(s) of general formula TiOx, the value of x being between 1.6 and 1.9, the method including a) mixing the raw materials including at least one source of titanium dioxide, a reducing agent comprising carbon, b) forming the product, c) optionally, in particular when organic products are used during step a), thermal treatment under air or an oxidizing atmosphere, d) sintering, for example at a temperature above 1150° C. but not exceeding 1430° C., under a neutral or reducing atmosphere, in which the source of titanium dioxide consists of at least 55 wt % of anatase.

Abstract: A filter for the filtration of a fluid, such as a liquid, includes or composed of a support element made of a porous ceramic material, the element having a tubular or parallelepipedal shape delimited by an external surface and including, in its internal portion, a set of adjacent channels with axes parallel to one another and separated from one another by walls of the porous inorganic material, wherein at least a portion of the channels and/or at least a portion of the external surface are covered with a porous separating membrane layer, wherein the layer is made of a material essentially composed of sintered grains of silicon carbide (SiC), and the weight content of elemental oxygen of the layer is less than 0.5%.

Abstract: The invention relates to a communication device using radio waves with frequencies of 800 MHz to 3 GHz, comprising a ceramic cover at least partially exposed to the external environment of the device, at least one portion of said waves passing therethrough during the use of the device, said cover being at least partially made of a sintered product having a chemical composition such as, by weight and for a total of 100%, 32%?ZrO2?95%, 1%<Y2O3+CeO2+Sc2O3+MgO+CaO, 0%?CeO2?26%, 0%?MgO?43%, 0%?CaO?37%, 0%?SiO2?41%, 0%?Al2O3?55%, 0%?TiO2?30%, 0%?lanthanide oxide, except for CeO2?50% 0% SrO?24%, o %?iAlON compounds ?50%, and other compounds ?15%.

Abstract: An article with a sintered decorative part obtained from a particulate mixture having the following chemical composition: zirconia ZrO2: complement to 100%; 0.5% to 10.0% of oxide(s) with a perovskite structure; 2.0% to 20.0% of a stabilizer for zirconia selected from Y2O3, Sc2O3, MgO, CaO, CeO2, and mixtures thereof, the quantity MgO+CaO being less than 5.0%; less than 2.0% of a sintering additive selected from Al2O3, ZnO, TiO2, and mixtures thereof; and less than 2.0% of other oxides.

Abstract: The invention relates to a communication device using radio waves with frequencies of 800 MHz to 3 GHz, comprising a ceramic cover at least partially exposed to the external environment of the device, at least one portion of said waves passing therethrough during the use of the device, said cover being at least partially made of a sintered product having a chemical composition such as, by weight and for a total of 100%, 32%?ZrO2?95%, 1%<Y2O3+CeO2+Sc2O3+MgO+CaO, 0%?CeO2?26%, 0%?MgO?43%, 0%?CaO?37%, 0%?SiO2?41%, 0%?Al2O3?55%, 0%?TiO2?30%, 0%?lanthanide oxide, except for CeO2?50% 0%SrO?24%, o %?iAlON compounds ?50%, and other compounds ?15%.

Abstract: An article with a sintered decorative part obtained from a particulate mixture having the following chemical composition: zirconia ZrO2: complement to 100%; 0.5% to 10.0% of oxide(s) with a perovskite structure; 2.0% to 20.0% of a stabilizer for zirconia selected from Y2O3, Sc2O3, MgO, CaO, CeO2, and mixtures thereof, the quantity MgO+CaO being less than 5.0%; less than 2.0% of a sintering additive selected from Al2O3, ZnO, TiO2, and mixtures thereof; and less than 2.0% of other oxides.

Abstract: The invention relates to a structure for the purification of a contaminated gas, for example the exhaust gas from a diesel or petrol engine, the structure incorporating an electrochemical system for treating said gas, composed of an NOx reduction catalyst A, a hydrocarbon oxidation catalyst B, an electron-conducting compound C and an ion-conducting compound D, said structure being characterized in that it is made of or covered with at least one porous, inorganic, electron-conducting and/or ion-conducting material in such a way that the catalysts A and B are disposed in the porosity of the inorganic material and that the ion-conducting, electron-conducting or ion-conducting and electron-conducting inorganic material makes up, respectively, the element C, the element D, or the sum of the elements C and D of said electrochemical system.

Abstract: The invention relates to a process for manufacturing a porous silicon carbide structure of the honeycomb type, said process being characterized in that it comprises the following steps: forming of a paste from a mixture of silicon carbide grains, the diameter d50 of which is between 5 ?m and 300 ?m, of an organic binder and of an inorganic pore former, in the form of particles based on silica, the overall porosity of said particles being greater than 70%; forming of a honeycomb-shaped green plastic monolith; drying of said monolith; and firing of the monolith at a temperature greater than 2100° C. The structure obtained by the process may be used as catalytic support in an exhaust line of a diesel or petrol engine or as particulate filter in an exhaust line of a diesel engine.

Abstract: The present invention relates to an acetabular cup for receiving a substantially spherical hip joint prosthesis head having an outer surface, the cup including: (a) a ceramic component having a socket surface shaped to rotatably receive the outer surface of the head, and (b) a metal backing in which the ceramic component is received, wherein the ceramic component comprises zirconia-toughened alumina, and wherein the ceramic component is interference fit within the metal backing.

Abstract: This invention relates to a biojoint prosthesis comprising:

Abstract: This invention relates to a biojoint prosthesis comprising:a) a prosthetic comprising a first component having an outer surface comprising at least 90 mol% zirconia, andb) a second component having a surface shaped to receive the outer surface of the first component,wherein the outer surface of the first component is received on the surface of the second component, andwherein a) at least a portion of the surface of the second component receiving the first component comprises a ceramic having a surface roughness of no more than 100 nm, and b) the outer surface of the first component has a surface roughness of no more than 100 nm.

Abstract: The invention relates to a refractory thermally-insulating component consisting essentially of refractory ceramic fibers which are mechanically combined with one another, the composition of which comprises at least 97.5% by weight of alumina, silica and zirconia in total, wherein:a) no organic or inorganic binder binds the fibers to one another;b) the fibers have the following chemical composition, as % by weight:Al.sub.2 O.sub.3 : 33-45%SiO.sub.2 : 41-53%ZrO.sub.2 : 5.5-17%MgO: 0.02-2%other oxides:<0.50% with Fe.sub.2 O.sub.3 +TiO.sub.2 .ltoreq.0.20% and Na.sub.2 O+CaO+K.sub.2 O.ltoreq.0.30%;c) the said fibers homogeneously have, throughout the entire body of the component, a degree of crystallinity of not less than 30% and not more than 64%, the crystals present being essentially formed of mullite crystals and of quadratic zirconia; andd) the said component has a linear shrinkage of no more than 3% after being held for 24 hours at 1450.degree. C.

Abstract: The invention relates to fused ceramic beads, which have the following chemical composition in % by weight on the basis of the oxides:40 to 95% of ZrO.sub.2 and HfO.sub.2 ;at least one of Y.sub.2 O.sub.3 and CeO.sub.2, with the provisos that Y.sub.2 O.sub.3, when present, represents 0.1 to 10% and CeO.sub.2, when present, represents 1 to 25%, the total of Y.sub.2 O.sub.3 and CeO.sub.2 representing 0.1 to 25%;a quantity of SiO.sub.2 representing 10 to 45% of the composition when CeO.sub.2 is absent from the composition and 0.5 to 45% when CeO.sub.2 is present in the composition. Application to grinding and to dispersion in wet medium is provided.

Abstract: Reactive derivatives of zirconium, are provided which are in the form of a pulverulent white, non-crystallized solid which is dry in appearance, and consist of metazironic acid, ZrO (OH).sub.2, accompanied by free or weakly bound water, some of the OH.sup.- ions being optionally replaced by halide ions. The ZrO.sub.2 content of these derivatives is from 60 to 92% by weight inclusive, the water content ranges from 3 to 40%, and the halide ion content can range up to approximately 5% by weight. The solid derivatives of the invention can be easily converted into usual reactive derivatives of zirconium by reaction with an aqueous solution of an acid.

Abstract: A process for the preparation of improved zirconium oxides comprising A) providing a zirconium oxide which has been produced by thermal decomposition of zircon followed by chemical digestion of the resultant silicate phases, B) reacting the zirconium oxide at high temperature with an alkali metal hydroxide or carbonate so as to form an alkali metal zirconate, C) hydrolyzing the resultant alkali metal zirconate so as to produce a suspension of zirconium oxide hydrate in a concentrated solution of alkali metal hydroxide, D) separating the zirconium oxide hydrate from the concentrated solution and washing the zirconium oxide hydrate which has been isolated, and E) drying the zirconium oxide hydrate at a temperature in the range of from 110.degree. to 570.degree. C.

Abstract: A process for the preparation of zirconia hydrate from zirconia by reaction of the latter with solid sodium hydroxide at 550.degree.-1,400.degree. C. to form Na zirconate; hydrolysis of the latter to form a suspension of zirconia hydrate in aqueous sodium hydroxide; separation of most of the aqueous sodium hydroxide; treatment of the zirconia hydrate containing residual aqueous sodium hydroxide with an ammonium salt; and separation, washing and dewatering of the purified zirconia hydrate obtained.The zirconia hydrate can be used for the preparation of zirconium compounds.

Abstract: The invention relates to the chemistry of zirconium.It relates particularly to a reactive zirconium oxide in the form of fine particles whose median diameter does not exceed 10 .mu.m, which has a structure chosen from the amorphous structure and the structure crystallized in the tetragonal form, the size of the elementary coherence regions in the latter case being between 10 and 30 nm, and which has a B.E.T. surface area of at least 30 m.sup.2 /g, and to a process for its preparation.Use in the field of ceramic materials.

Abstract: The invention relates to ceramic articles.It relates to an article made of ceramic material produced by fusing and casting in a mold a composition based on alumina, zirconia, silica and an alkali metal oxide, said article consisting of crystalline corundum and zirconia phases and of a vitreous phase, said zirconia being substantially in monoclinic form from the core to the skin of said article, and having, in at least one of its parts, a thickness lower than or equal to 30 mm and being intended for an application where mechanical strength and/or abrasion resistance are of primary importance, said composition consisting essentially, in % by weight based on the oxides, of:______________________________________ Al.sub.2 O.sub.3 40-75 ZrO.sub.2 20-55 SiO.sub.2 5-20 Na.sub.2 O 0-2.7 K.sub.2 O 0.15-4.25 Fe.sub.2 O.sub.3 + TiO.sub.2 + CaO + MgO 0-2, ______________________________________with the condition that the weight ratio ##EQU1## is between 0.07 and 0.14 inclusive.