Abstract: Provided herein is a separating device for removing sand and rock particles in the extraction of liquids or gases from wells drilled in rock having a plurality of brittle-hard annular discs stacked one on top of another and axially braced by a supporting structure. The annular discs have at least three spacers uniformly distributed over the circumference on their upper side. The discs are stacked on each other such that the spacers lie one over another and a separating gap with a height of 0.05-1 mm, preferably 0.2-0.5 mm, is present between each of the discs. Similarly, another embodiment of the separating device has a plurality of brittle-hard bush-shaped elements with slits formed therein.

Abstract: The invention relates to titanium diboride granules comprising aggregates of titanium diboride primary particles, wherein the titanium diboride granules have a rounded shape and are fracture-resistant. The invention further relates to a method for producing these titanium diboride granules, the use thereof for covering graphite cathodes in electrolytic cells in Al fused-salt electrolysis or for repairing holes in cathode bases of electrolytic cells and also a method for repairing holes in cathode bases of electrolytic cells.

Abstract: The invention relates to a shaped body comprising a substrate with a firmly adhering separating layer, wherein the separating layer comprises 92-98 wt. % silicon nitride (Si3N4) and 2-8 wt. % silicon dioxide (SiO2) and wherein the separating layer has a total oxygen content of ?8 wt. % and a hardness of at least 10 HB 2.5/3 according to DIN EN ISO 6506-1. The invention further relates to a process for producing such a shaped body, a coating suspension for use in such a process and the use of a shaped body according to the invention in the field of corrosive nonferrous metal melts.

Abstract: The invention relates to a separating device for tubular flow-through devices (22) which serve for the extraction of liquids or gases from wells drilled in rock or deep wells, the separating device being suitable for the removal of sand and rock particles and comprising an annular stack (20) of brittle-hard annular disks, the disks (30) being stacked and braced in such a way that a separating gap (37) for the removal of sand and rock particles is present in each case between the individual disks (30), a coupling-on element (18, 19) at one or both ends of the annular stack (20), a clamping device at one or both ends of the annular stack (20), making it possible on the one hand to flexibly brace the brittle-hard disks (30) and on the other hand to variably fasten the annular stack (20) on the tubular flow-through device (22).

Abstract: A separating device for removing sand and rock particles, and is an integral component of extraction equipment for extraction of liquids or gases from deep wells, having at least one ceramic filter module comprising: an annular stack of annular discs, the upper side of which has at least three elevations uniformly distributed over the circumference of the discs, the discs are stacked such that a separating gap for the removal of sand and rock particles is present between the individual discs, a coupling-on element at the upper end and a coupling-on element at the lower end of the annular stack, a clamping device bracing the annular stack, an outer cage, a coupling element at the upper end and a coupling element at the lower end of the filter module connecting the filter module to further components of the extraction equipment.

Abstract: The invention relates to a component comprising a plurality of plates stacked on each other, at least one of said plates being made of a ceramic material and in which a channel area is formed of fluid flow guide channels by means of webs, said channels having a flow connection to inlet and outlet openings, wherein the stack of plates is connected by force fit by means of a clamping device, and wherein a flat seal is disposed between each of the individual plates of the stack, wherein the flat seal is made of an elastic and/or compressible material and covers both the channel area and the areas encompassing the inlet and outlet openings, and at least partially covers the top sides of the webs forming the channels. The components according to the invention are pressure-tight, resistant to thermal shock, and can be dismantled.

Abstract: Described is a device and method for a securing element for screw connections as an interlayer, between the screw head and supporting material and/or between the nut and supporting material, the basic body of the element consisting of a metallic material, to the top side and underside of which hard material particles are fixed, wherein the hard material particles are fixed by means of a metallic binding phase, the thickness of the metallic binding phase being lower than the mean diameter of the hard material particles, so that the hard material particles project out of the metallic binding phase.

Abstract: The invention relates to a slip for producing a durable, firmly adhering release layer on a substrate, comprising a suspension of solid particles, wherein the solid particles comprise 67-95% by weight of silicon nitride and 5-33% by weight of an SiO2-based high-temperature binder and the SiO2-based high-temperature binder is derived from SiO2 precursors and has been pretreated by heat treatment in a temperature range of 300-1300° C. The invention further provides shaped bodies comprising a substrate having a durable, firmly adhering release layer and also processes for producing them. The shaped bodies of the invention are suitable for use in the field of corrosive nonferrous metal melts.

Abstract: The invention relates to a separating device for tubular flow-through devices (22) which serve for the extraction of liquids or gases from wells drilled in rock or deep wells, the separating device being suitable for the removal of sand and rock particles and comprising an annular stack (20) of brittle-hard annular disks, the disks (30) being stacked and braced in such a way that a separating gap (37) for the removal of sand and rock particles is present in each case between the individual disks (30), a coupling-on element (18, 19) at one or both ends of the annular stack (20), a clamping device at one or both ends of the annular stack (20), making it possible on the one hand to flexibly brace the brittle-hard disks (30) and on the other hand to variably fasten the annular stack (20) on the tubular flow-through device (22).

Abstract: The invention relates to a suspension for producing a friction-increasing layer on a substrate, which comprises a liquid suspension medium, a predominantly inorganic binder or precursor compounds thereof and suspended hard material particles. The invention further relates to a shaped body comprising a substrate and a friction-increasing layer which has been applied to at least part of the surface of the substrate and comprises a predominantly inorganic binder matrix and hard material particles embedded therein, where the thickness of the binder matrix is less than the average particle size of the hard material particles so that the hard material particles project from the binder matrix and where the friction-increasing layer has been formed from a suspension according to the invention. The invention likewise relates to a process for producing the abovementioned shaped bodies and also their use for producing press or clamp connections and also as securing element.

Abstract: The invention relates to boron nitride agglomerates, comprising lamellar, hexagonal boron nitride primary particles, which are agglomerated with one another with a preferred orientation, the agglomerates formed being flake-shaped. The invention also relates to a method for producing said boron nitride agglomerates, characterized in that lamellar, hexagonal boron nitride primary particles are agglomerated in such a way that they line up with one another with a preferred orientation. The flake-shaped agglomerates according to the invention are suitable as filler for polymers for making polymer-boron nitride composites and for hot pressing of boron nitride sintered compacts.

Abstract: The invention relates to a water-containing slip for producing a BN-containing coating on a substrate, which comprises, based on the solids content of the slip, a) 45-90% by weight of BN, b) 3-25% by weight of boehmite nanoparticles, c) 0.5-5% by weight of at least one borate, d) 2-30% by weight of at least one water-insoluble boron compound which is different from the components a) and c), e) 2-30% by weight of an organic compound, where the solids content of the slip is 15-60% by weight.

Abstract: The subject matter of the invention is a separating device for removing sand and rock particles which is suitable as an integral component part of extraction equipment for the extraction of liquids or gases from deep wells, the separating device comprising at least one ceramic filter module (1), the filter module (1) comprising a) an annular stack (6) of brittle-hard annular discs (7), the upper side (16) of which has at least three elevations (8) uniformly distributed over the circular circumference of the discs, the discs (7) being stacked and braced in such a way that a separating gap (9) for the removal of sand and rock particles is present in each case between the individual discs (7), b) a coupling-on element (10) at the upper end and a coupling-on element (11) at the lower end of the annular stack (6), c) a clamping device (14, 15) for the axial bracing of the annular stack (6), d) an outer cage (5) for the mechanical protection of the filter module (1), e) a coupling element (12) at the upper end a

Abstract: A process for joining ceramic components, wherein the components which are to be joined consist of sintered nonoxide ceramic, and the components are brought into contact with one another in a diffusion-welding process in the presence of a shielding gas atmosphere and are joined with little deformation, under the application of a temperature of at least 1600° C., preferably over 1800° C., particularly preferably over 2000° C., and if appropriate a load, to form a monolith, the components which are to be joined experiencing plastic deformation in the direction in which force is introduced of less than 5%, preferably less than 1%.

Abstract: According to a first embodiment, the invention relates to a separating device for removing sand and rock particles in the extraction of liquids or gases from wells drilled in rock, comprising a plurality of annular discs of a brittle-hard material stacked one on top of the other and axially braced by means of a supporting structure, the discs having on their upper side at least three spacers uniformly distributed over the circular circumference of the discs, the discs being stacked one on top of the other in such a way that the spacers respectively lie one over the other, and that a separating gap with a height of 0.05-1 mm, preferably 0.2-0.5 mm, is present in each case between the individual discs.

Abstract: The invention relates to a slip for producing a durable hard coating on a substrate, comprising a) silicon nitride particles and b) a binder comprising nanosize solid particles and/or precursors of nanosize solid particles from production via a sol-gel process. The invention further relates to shaped bodies composed of a substrate with a durable hard coating which has been produced from a slip according to the invention. The shaped bodies of the invention are suitable for use in the field of corrosive nonferrous metal melts.

Abstract: The invention relates to a component comprising a plurality of plates (1) stacked on each other, at least one of said plates being made of a ceramic material and in which a channel area is formed of fluid flow guide channels (3) by means of webs (2), said channels having a flow connection to inlet and outlet openings (4, 5, 6, 7), wherein the stack of plates is connected by force fit by means of a clamping device, and wherein a flat seal (8) is disposed between each of the individual plates (1) of the stack, wherein the flat seal (8) is made of an elastic and/or compressible material and covers both the channel area and the areas encompassing the inlet and outlet openings (4, 5, 6, 7), and at least partially covers the top sides of the webs (2) forming the channels. The components according to the invention are pressure-tight, resistant to thermal shock, and can be dismantled. They are particularly well suited as heat exchangers and microreactors.

Abstract: The invention relates to a method for fixing on a metal workpiece a connecting element which permits the friction-increasing, play-free, reversible connection of workpieces to be joined, the connecting element comprising a metal foil which bears on its joining surfaces hard material particles, which are fixed on the metal foil by means of a metallic binder phase, characterized in that the connecting element is fixed on the metal workpiece securely for purposes of assembly and transportation by welding involving the formation of locally confined weld points.

Abstract: The invention relates to a securing element for screw connections as an interlayer between the screw head and supporting material and/or between the nut and supporting material, the basic body of the element consisting of a metallic material, to the top side and underside of which hard material particles are fixed, wherein the hard material particles are fixed by means of a metallic binding phase, the thickness of the metallic binding phase being lower than the mean diameter of the hard material particles, so that the hard material particles project out of the metallic binding phase. The invention also relates to the use of a securing element according to the invention for highly loaded, permanent and rereleasable screw connections, the securing element being used as an interlayer between the screw head and supporting material and/or between the nut and supporting material.

Abstract: A process for joining ceramic components, wherein the components which are to be joined consist of sintered nonoxide ceramic, and the components are brought into contact with one another in a diffusion-welding process in the presence of a shielding gas atmosphere and are joined with little deformation, under the application of a temperature of at least 1600° C., preferably over 1800° C., particularly preferably over 2000° C., and if appropriate a load, to form a monolith, the components which are to be joined experiencing plastic deformation in the direction in which force is introduced of less than 5%, preferably less than 1%.