Abstract: The invention relates to a high voltage insulator of ceramic material, which includes a longitudinal shank having molded sheds and to whose ends of the shank metal caps are shrink-fitted. The ends of the longitudinal shank are enlarged so that the diameter of the enlarged ends is at least 1.05 times the diameter of the longitudinal shank. The cylindrical surface, and the end face of the enlarged ends of the longitudinal shank are machined.

Abstract: The invention relates to a composite disk for use as inlet or regulating disk, wherein a support disk and at least one hard material disk having a functional surface are arranged above one another, the support and hard material disks are joined to one another by frictional fastening, forcelocking, formlocking, mechanical interlocking, retention by self substance and/or bonding, the support disk has a thickness of at least 0.6 mm and the hard material disk has a thickness of from 0.05 to 2.5 mm and the hard material disk comprises a material having a Vickers microhardness of at least 1300 HV 0.5.

Abstract: In the permeable structure, which is built up of sheets, continuous channels are arranged in rows and between the rows of channels are formed flow spaces which at opposite sides are bounded bit cover plates. In the flow spaces (4) at least two successive transverse bridges (6) are arranged on the same level, the transverse bridges (6) in at least half of the sheets having a different length (B) and the channels (1) extending essentially perpendicular to the flow spaces (4).

Abstract: A corundum porcelain composition containing from 60 to 94% by weight of a component A and from 6 to 40% by weight of a component B, wherein component A contains from 0 to 70% by weight of alumina, from 20 to 70% by weight of clay material, from 10 to 50% by weight of glass formers and from 0 to 30% by weight of quartz, and component B comprises comminuted broken porcelain, the chemical composition of the mixture of the components A and B comprises from 20 to 75% by weight of SiO.sub.2, from 15 to 80% by weight of Al.sub.2 O.sub.3 and from 2 to 10% by weight of flux selected from the group consisting of K.sub.2 O, Na.sub.2 O, FeO, MgO, CaO, Li.sub.2 O; BaO, SrO, ZnO and fluoride, and the comminuted broken porcelain has a mean particle size between 25 and 800 .mu.m, useful, for example, in sintered bodies, such as insulators.

Abstract: The invention relates to a process or producing components of silicon carbide with addition of carbon and/or carbon-containing binders, in which the carbon is obtained at least in part by pyrolysis of the binders in the green component. The binder used is, according to the invention, modified starch preferably with a sulfamate or a sulfonic ester which is dispersible and/or soluble and/or dissolved in water.

Abstract: A process for producing an electric heating element is disclosed whereby metallic heating conductors are embedded between ceramic insulating layers, and, as power supply leads and power outlet leads, contact recesses in the ceramic insulating layers are filled with an electrically conductive composition. The heating conductors, the power supply leads and the power outlet leads are applied to the ceramic layers in the green state as metallizing paste containing from 60 to 95% by weight of metal particles and from 5 to 40% by weight of inorganic powder, based on the total solids content of the paste. The ceramic layers with the applied metallizing pastes are then stacked on top of one another and then sintered.

Abstract: In the method of operating heat exchangers by means of hot gas streams containing condensable components, the hot gas stream (1) is divided into substreams (4) and cooled by means of obstacles (3) having a temperature T which is small in comparison with the entry temperature T.sub.I of the hot gas stream (1), in particular less than the dew point temperature T.sub.D of the hot gas stream (1). The substreams (4) are, after leaving the obstacles (3), combined with one another and, in their cores (8), divided into other substreams (6) and cooled by means of further obstacles (3) at the temperature T. This procedure is repeated until the hot gas stream (7) leaving the heat exchanger (2) reaches an exit temperature T.sub.O of from 200.degree. C. to 60.degree. C., preferably from 120.degree. C. to 80.degree. C.

Abstract: The invention relates to a composite body in which a ceramic component and a metal component are bonded to one another by internal soldering. The internal soldering is effected with soldering composition in a recess (2) within a component (1) of the one material in which there is arranged a component (3) of the other material which is shaped to fit accurately. The recess (2) is, at at least one end-face opening, surrounded by a chamfer (5) having an angle .phi. smaller than 35.degree. C., while the wetting angle .beta. between the soldering composition and the plane of the component surface in which the recess is located is smaller than 40.degree..

Abstract: Ceramic moldings composed of aluminum oxide which have a proportion of intercrystalline fracture of more than 50%, an average pore radius of more than 4 .mu.m and a porosity of more than 2%, are obtained by:a) grinding aluminum oxide which is at least 99.5% pure and has an average primary crystal size of 1 to 4 .mu.m to an average fragment size of 2 to 7 .mu.m,b) adding a source of magnesium oxide, silicon oxide and calcium oxide in amounts such that the magnesium oxide content is 0.2 to 2.5%, the silicon dioxide content is 1 to 6% and the calcium oxide content is 0.1 to 2.5%, in each case with respect to the amount of Al.sub.2 O.sub.3,c) shaping a green compact andd) sintering.

Abstract: A process is described for producing carbon bodies and a coating of silicon-infiltrated silicon carbide. In this process, the surface of carbon bodies is coated with an aqueous slip containing finely divided silicon carbide and binder. The coating is then dried and the binder is decomposed by heat. The coated carbon bodies are then silicized at their surface by contact with liquid silicon.

Abstract: In the ceramic insulating block for halogen lamps, which has a shallow channel with a re-entrant projection at its exit side, the insulating block (1) is provided at the entry side (9) of the shallow channel (2) with a recess (10) having a bell-shaped contour. The apex (11) of the recess extends towards the exit side (4) of the shallow channel (2). The recess has an apex height H.sub.s of .ltoreq.40%, an apex radius R.sub.s of .ltoreq.20% of the height H of the insulating block (1) and a base radius R.sub.B of between 140% and 60% of R.sub.S.

Abstract: To prepare a ceramic molded article based on silicate or based on alumina, a ceramic starting material containing clay, kaolin, steatite and/or alumina is mixed with a silicate-containing flux, the mixture is made into a molded article and the molded article is heated and dense-sintered. At least some of the flux used is composed of a preferably alkali metal-free glass frit whose beginning of softening is above 850.degree. C.Advantageously, an alkali metal-free boron silicate glass is used in amounts of 0.1-20% by weight of the starting mixture. This process makes it possible to prepare, inter alia, ceramic molded articles comprising a glass phase and a crystalline portion substantially containing Al.sub.2 O.sub.3, in which the glass phase content is 22-34% by weight and comprises 50-68% by weight of SiO.sub.2, 12-22% of Al.sub.2 O.sub.3, 0.1-4.5% of Fe.sub.2 O.sub.3, 0.1-13% of TiO.sub.2, 0.1-23% of CaO, 0.1-9% of MgO, 0-7% of Na.sub.2 O, 0-11% of K.sub.2 O, 0-9% of BaO and 0-23% of B.sub.2 O.sub.

Abstract: Silicon slip-casting composition, and process for the preparation thereofA silicon slip-casting composition comprising from 25 to 50% by weight of water and a pulverulent solid component which essentially comprises silicon and inorganic sintering aids is described, where the aqueous phase has a pH in the range from 8 to 9.5. The solid component comprises from 65 to 88% by weight of silicon, from 5 to 24% by weight of Y.sub.2 O.sub.3, from 2 to 9.6% by weight of Al.sub.2 O.sub.3 and from 1 to 5% by weight of SiO.sub.2 on the surface of the Si particles.The mean particle size of the solid component is at most 20 .mu.m, in particular at most 5 .mu.m. The invention also relates to a process for the preparation of the slip-casting composition.

Abstract: A process is described for electrolessly depositing or electrodepositing a solder layer composed of copper and silver and having an overall composition of silver/copper of from 75:25 to 70:30 and a total layer thickness of 15 to 100 .mu.m on a metallized ceramic. In this process, copper layers and silver layers are deposited alternately on the metallized ceramic. The number of layers is at least 3 and the individual layer thickness is 5 to 10 .mu.m.

Abstract: In the contact pin with ceramic insulation, one end is provided with a tongue for receiving a pole shoe and the other end is provided with a step which rests against a corresponding step in the flat channel running through the ceramic insulation. The first step of the contact pin is followed by a second step which projects slightly out of the channel and is provided with an upsetting.

Abstract: For silicizing porous moldings of silicon carbide/carbon, a mixture of silicon carbide powder, organic binder and, if appropriate, carbon is molded to give a green compact, the binder of the green compact is removed by carbonization at about 1000.degree. C. in a non-oxidizing atmosphere and the resulting blank is silicized by the action of molten silicon, while the resulting blank rests on a porous SiSiC carrier, whose lower part is in contact with the molten silicon. The carrier used may be a close packing of porous SiSiC rings which are arranged mutually parallel and perpendicularly on a graphite firing plate which is charged with silicon and is impermeable to molten silicon; or the carrier may be plane having a plurality of recess; or the carrier may have a straight channel with an angular cross section and recesses, into which the blank to be silicized is placed, wherein the SiSiC carrier has downward protruding side walls, whose undersides are in contact with the molten silicon.

Abstract: A valve disk of silicon-infiltrated silicon carbide material for control elements for regulating liquid flows is suitable in particular for service-water mixer valves. The silicon carbide material contains 70 to 90% by weight of silicon carbide and 8 to 30% by weight of silicon with a content of most 0.2%, by weight of free carbon and contains at most 0.1% by volume of closed pores. The valve disk has a functional surface having the optical appearance in the form of isolated islands of bearing surfaces surrounded by a level lying lever with respect to the isolated islands, the functional surface having the following microtopographical characteristics over its entire region: R.sub.a : 0.02 to 0.80 .mu.m, preferably 0.15 to 0.40 .mu.m; R.sub.t : 0.50 to 6.00 .mu.m,; R.sub.z : 0.20 to 100 .mu.m: flatness: 0.0002 to 0.01 mm; t.sub.pi : 40 to 80% (at 0.3 .mu.m cut depth); t.sub.pa : 10 to 60% (at 0.3 .mu.m cut depth). The invention also relates to a process for producing the valve disk.

Abstract: A surge voltage protector having a tubular ceramic part as an insulator, and having metal electrodes soldered onto the end faces thereof. Each electrode is electrically connected in each case to an ignition aid applied at least to the inside wall of the ceramic part. The inside edges of the surfaces joining the ceramic part to the electrodes are each provided with a chamfer whose chamfer angle is 15.degree. to 60.degree. relative to the plane of the joining surfaces. The width projected onto the plane of the joining surface is 0.05 to 0.4 mm.

Abstract: In the finned-tube heat exchanger of silicon-infiltrated silicon carbide, in which the tubes of a tube bundle, with the cooling medium flowing around the tubes, are arranged mutually parallel in a housing provided with an inlet and outlet for the cooling medium, the tubes of the tube bundle are joined to one another by fins. The fins have apertures and are arranged transversely to the tube bundle.

Abstract: To produce a piezoelectric tone generator, a layer of filler-free bonding agent whose dynamic viscosity is 800 to 18,000 mPa.multidot.s is applied between a metallized carrier plate and a piezoceramic wafer. The package composed of carrier plate, bonding layer and ceramic plate is pressed together, the quantity of bonding agent being chosen to be so large that during pressing a bead covering the edge of the ceramic wafer is formed. The bonding layer is cured thereafter, firstly catalytically or thermally and then by UV irradiation.