Hoechst Aktiengesellschaft

W.c. Heraeus Gmbh

Heraeus Quarzschmelze Gmbh

Heraeus Quarschmelze Gmbh

Kontron Ag

Fritz Aldinger

Hans-Jerg Kleiner

Martin Bruck

Marcellus Peuckert

Waltraud Werdecker

Thomas Gerdau

Tilo Vaahs

Franz Sperner

Albrecht Bischoff

Richard Keilberth

Wilhelm Zwergel

Steffen Elschner

Andreas Roosen

Nils Harmsen

Rolf Bruning

Christine Kostler

Bernhard Hettich

Elke Biberbach

Peter Majewski

Norbert Cibis

Harro Bestgen

Poul-Erik Breidenbach

Harry Heinke

Franz Schreiber

Adrien Bussard

Guenter Petzow

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.

Process for increasing the pinning force of superconducting

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.

Oxygen sensor and method of producing it

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.

Process of producing a ceramic/fiber composite using a molten

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.

High-strength ceramic composite, process for its preparation and its use

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.

Polysilazanes, process for the preparation thereof, silicon,

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)

Sinterable ceramic powder, process for its preparation, silicon nitride

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.

Process for the production of ceramic material containing silicon

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.

Polymeric hydridosilazanes and processes for their preparation, and

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.

Polymeric hydridochlorosilazanes and processes for their preparation

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.

Polysilazanes, process for the preparation thereof, silicon

Polymeric hydridosilazanes and processes for their preparation and their

The temperature stabilization body is made of pulverized aluminum nitride with a first additive of pulverized aluminum present between 0.05% to 2%, and a grain size of under 1 micrometer, and a second additive of from 0.1% to 10% of an oxide, preferably yttrium oxide, present at about 1%--all precentages by weight, in which the mixture is ground in a ceramic ball mill to a grain size of not over 0.1 mm, subjected to cold isostatic pressure in the order of 2500 bar to form a green, pressed body, and then sintered at a sintering temperature of between 1750.degree. C. to 2000.degree. C. The heat conductivity of the densely sintered aluminum nitride body will then be at least 140 W/m .degree.K., and a heat conductivity of twice as much can be obtained, the body being non-toxic and not subject to creep under temperatures up to at least 1700.degree. C.

Ceramic temperature stabilization body, and method of making same

A heat conductive ceramic substrate for semiconductor circuits, comprising polycrystalline aluminum nitride of high density containing as an additive boron nitride or oxides of calcium, magnesium, aluminum, titanium, zirconium, chrome, silicon, and/or rare earth metals. The boron nitride additive concentration ranges between 0.1 and 3% by weight, preferably between 0.5 and 2% by weight. The oxide additive concentration ranges between 0.1 and 5% by weight. The substrate has a significantly higher thermal conductivity than aluminum oxide substrates and is more economincal to manufacture than beryllium oxide substrates.

Combination of AlN-Y.sub.2 O.sub.3 heat conductive ceramic substrate and

A low contamination crucible for pulling monocrystals of Group III and Group V elements of the Periodic Table, comprising particularly aluminum nitride with an additive of boron nitride or a rare earth oxide. The additive concentration is up to 5% by weight, but preferably 0.5% to 3% by weight. The hardness of the crucible of the invention is 300 to 400% greater than that of undoped material subjected to the same sintering conditions.

Low-contamination AlN crucible for monocrystal pulling and method

A cable for connecting a cardiac pacemaker to an electrode inserted in the heart through the blood stream utilizes a die-clad conductor or a number ofthem, especially several die-clad strands forming a twisted conductor of the stranded type, enclosed in a covering tube of a synthetic elastomer. The core of each die-clad strand is of a highly conducting metal, such as copper or a high-copper alloy. The outer cladding is a metal selected from the group consisting of tantalum, titanium, zirconium, niobium, titanium-base alloys, platinum, platinum-iridium alloys, platinum-palladium alloys and platinum-rhodium alloys. The cladding thickness is in the range from 0.0025 to 0.035 mm, while the cord diameter is between 0.04 to 0.3 mm. When tantalum, titanium, zirconium, niobium or titanium-alloy cladding is used, the outer surface can be made electrically insulating, preferably by anodizing.

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Rodenbach, Germany

Fritz Aldinger