Abstract: The invention relates to a product (1), particularly a gas turbine blade that can be exposed to a hot aggressive gas (7). The product (1) has a metallic basic body (2), which is provided with a thermal barrier coating (4) having a spinel of the composition AB2O4.

Abstract: To produce reference electrodes for galvanic cells having solid electrolytes, comprising metal oxides or/and double oxides, at least one oxide or double oxide is prepared as a hydrosol or organosol and applied in liquid form to the electrolyte to form a solid film. Preferably, a double oxide Me1xMe2yOz and (i) a metal oxide Me2mOn or (ii) a double oxide Me1aMe2bOc with a lower Me1 content are present in the reference electrode material.

Abstract: An article that is particularly well suited for use as a gas turbine engine component has a metallic substrate and a ceramic thermal barrier layer including a mixed metal oxide system comprising a compound selected from the group consisting of (i) a lanthanum aluminate and (ii) a calcium zirconate, the calcium in which is partially replaced by at least one calcium-substitute element, such as strontium (Sr) or barium (Ba). In addition, the lanthanum in the lanthanum aluminate can be partially replaced by a lanthanum-substitute element from the lanthanide group, particularly gadolinium (Gd). A process for producing such an article comprises providing a pre-reacted mixed metal oxide system as described above and applying it to the substrate by plasma spraying or an evaporation coating process.

Abstract: The invention relates to a method for producing a solid molded article, in particular a ceramic and/or metallic article made of pulverized particles. The invention also relates to stable dispersions of pulverized particles in an aqueous fluid medium, solid molded articles made of pulverized particles, and sintered ceramic and/or metallic molded articles.

Abstract: An article that is particularly well suited for use as a gas turbine engine component has a metallic substrate and a ceramic thermal barrier layer including a mixed metal oxide system comprising a compound selected from the group consisting of (i) a lanthanum aluminate and (ii) a calcium zirconate, the calcium in which is partially replaced by at least one calcium-substitute element, such as strontium (Sr) or barium (Ba). In addition, the lanthanum in the lanthanum aluminate can be partially replaced by a lanthanum-substitute element from the lanthanide group, particularly gadolinium (Gd). A process for producing such an article comprises providing a pre-reacted mixed metal oxide system as described above and applying it to the substrate by plasma spraying or an evaporation coating process.

Abstract: A process for producing crack-free shaped ceramic bodies based on Si/C/N by hot pressing of crosslinked polysilazane powder and subsequent pyrolysis of the hot-pressed shaped body employs a pressing temperature higher than the temperature maximum of the TMA curve of the optimally crosslinked polymer.

Abstract: An article that is particularly well suited for use as a gas turbine engine component has a metallic substrate and a ceramic thermal barrier layer including a mixed metal oxide system comprising a compound selected from the group consisting of (i) a lanthanum aluminate and (ii) a calcium zirconate, the calcium in which is partially replaced by at least one calcium-substitute element, such as strontium (Sr) or barium (Ba). In addition, the lanthanum in the lanthanum aluminate can be partially replaced by a lanthanum-substitute element from the lanthanide group, particularly gadolinium (Gd). A process for producing such an article comprises providing a pre-reacted mixed metal oxide system as described above and applying it to the substrate by plasma spraying or an evaporation coating process.

Abstract: The present invention relates to a process for the application of an epitactic GaN layer to a substrate by pyrolysis of precursor compounds.

Abstract: The invention relates to a galvanic cell comprising a) an oxygen-ion-conducting solid electrolyte, b) a gas-sensitive material which contains at least one salt having the structural formula Mem(XOn)p, where Me is a metal, X stands for C, S or N, and the symbols m, n and p characterize the respective stoichiometric relations, c) a material, interposed between the oxygen-ion-conducting solid electrolyte and the gas-sensitive material, which allows conduction both by cations of the metal Me and by electrons and which seals off a potential-determining area of the solid electrolyte surface from the surroundings, making it impervious to gases therein, and d) two electronically conductive potential taps at surface areas of the oxygen-ion-conducting solid electrolyte.

Abstract: Thin, single-crystal SiC films are obtained by means of a pyrolysis process, the substrate to be coated being covered with a carbonaceous polysilane, the adhering layer being pyrolyzed in an inert atmosphere and the amorphous layer of SiC obtained in this way being crystallized by maintaining it at a temperature of over 700.degree. C. Using a special variation of the process, it is easy to form doped SiC films. To this end the dopant is added in the form of a silane compound.

Abstract: Use of a boron-containing sinter additive when synthesizing aluminum-oxide ceramics makes it possible to carry out the sintering process at temperatures below 1500.degree. C., which means that ion-conducting aluminum-oxide ceramics can be obtained.

Abstract: Process for increasing the pinning force of superconducting Bi-Sr-Ca-Cu-O ceramic moldings, which comprises heating the pure-phase 2212 phase of a Bi-Sr-Ca-Cu-O ceramic molding under pure oxygen or an oxygen-containing gas for from 1 to 40 minutes to a temperature of from 825.degree. to 900.degree. C. and generating secondary-phase precipitates in the process.

Abstract: A planar oxygen sensor based on zirconium dioxide is described which is suitable for measuring the oxygen content in combustion furnaces or in the exhaust gases of internal combustion engines. Disposed on an external surface of the sensor is a noble-metal measuring electrode and located in its interior is a reference electrode which is connected to an external contact and is enclosed by two zirconium dioxide layers. One of these layers has, in its region near the edge, a hole whose outwardly pointing part is sealed by a solder glass. The internal part of the hole is partially filled with sintered platinum which makes a conductive connection between a platinum wire, passing outwards through the hole, as external contact and a platinum conductor track which is disposed on the internal interface of the zirconium dioxide layer and which leads to the reference electrode. A method of producing the oxygen sensor is also described.

Abstract: The invention relates to a process for the production of a ceramic/fiber composite.The process comprises impregnating fibers with a molten polysilazane in a first step, converting the polysilazane in the fibers into the infusible state in a second step and, in a third step, heating the impregnated fibers to 800.degree. to 2000.degree. C. in an atmosphere of nitrogen, noble gas, or ammonia.

Abstract: The invention relates to a high-strength ceramic composite, in particular made from silicon nitride, a process for its preparation and its use. The process comprises impregnating an open-pore matrix with a molten polysilazane in a first step and, in a second step, heating the impregnated matrix to 800.degree. to 2500.degree. C. under a blanketing gas, such as nitrogen or a noble gas, or to 800.degree. to 1500.degree. C. under a gas containing ammonia. The high-strength ceramic composite prepared can be used as a component to be subjected to high thermal, mechanical or corrosive stress.

Abstract: The invention relates to novel polysilazanes, the preparation thereof, the further processing thereof to form silicon nitride-containing ceramic material, and this material itself. In order to prepare the polysilazanes, dialkylaminoorganyldichlorosilanes of the formula RSiCL.sub.2 --NR'R' are reacted with ammonia. The polysilazanes can then be pyrolyzed to form silicon nitride-containing ceramic material. The polysilazanes according to the invention dissolve in customary aprotic solvents.

Abstract: The invention relates to a novel sinterable ceramic powder, to its preparation, to its processing to form silicon nitride ceramic and to said material itself and its use. The sinterable ceramic powder is prepared by dissolving the polysilazane of formula (I)[CH.sub.3 SiHNH].sub.n [CH.sub.3 SiN].sub.nwhere n is about 10 to 12, in an organic solvent, suspending a pulverulent sinter aid in this solution and then evaporating the solvent and pyrolyzing the residue in an inert gas atmosphere at 500.degree. to 1600.degree. C.The resulting ceramic powder can be used to form a shaped article and then to manufacture silicon nitride ceramic by sintering. It is also possible, however, to form a shaped article from the as yet unpyrolyzed residue obtained after evaporation of the solvent, and then to pyrolyze and sinter said article.The ceramic obtained can be used to manufacture components subject to high mechanical, thermal and corrosive stress.

Abstract: The invention relates to a process for the production of ceramic material containing silicon nitride, such as fibers, coatings or moldings. In this process, polymeric hydridochlorosilazanes are rendered infusible at a temperature below their softening point by treatment with gaseous NH.sub.3 and are then pyrolyzed in an atmosphere containing NH.sub.3 at 700.degree. to 1500.degree. C. Fibers, coatings or moldings containing silicon nitride are produced by first producing appropriate structures from a melt of the polymeric hydridochlorosilazane and then rendering them infusible and pyrolyzing them.

Abstract: The invention relates to novel polymeric hydridosilazanes, processes for their preparation and their use for the preparation of ceramic material containing silicon nitride. To prepare the polymeric hydridosilazanes, polymeric hydridochlorosilazanes are reacted with NH.sub.3. To prepare the ceramic material containing silicon nitride, the polymeric hydridosilazanes are then pyrolyzed.

Abstract: The invention relates to novel polymeric hydridochlorosilazanes and a process for their preparation. The compounds according to the invention can be converted into polyhydridosilaznes by reaction with ammonia, and these can in turn be pyrolyzed to ceramic material containing silicon nitride. To prepare the polymeric hydridochlorosilazanes, oligohydridoalkylsilazanes (R.sup.1 SiHNH).sub.n are reacted with a dichlorohydridoalkylsilane R.sup.2 SiHCl.sub.2.