Abstract: A method of manufacturing porous ceramic articles is provided that includes forming a plurality of extruded green bodies from a ceramic precursor batch composition. The method also includes firing the extruded green bodies in a tunnel kiln to produce porous ceramic articles, periodically determining a shrinkage characteristic of at least one sample passing through the tunnel kiln, and adjusting a top soak temperature in the kiln if the shrinkage characteristic is outside of a predetermined range.

Abstract: A method for fabricating a sintered annular nuclear fuel pellet includes: molding nuclear fuel powder or granules to fabricate an annular nuclear fuel green body; inserting a rod-like shaped structure into the annular nuclear fuel green body; sintering the rod-like shaped structure-inserted annular nuclear fuel green body in a reductive gas atmosphere; and separating the sintered annular nuclear fuel pellet from the rod-like shaped structure.

Abstract: A method for determining a sintering shrinkage of a pre-sintered body. The method includes providing a green preform with at least one design feature. The green-preform is pre-sintered to form a white body. At least one change in the at least one design feature with the pre-sintering is recorded. An expected sintering shrinkage to a dense-sintered component is determined using the recorded change.

Abstract: The present invention relates to a device and process for dimensionally stable sintering of ceramic pre-shaped dental articles, the device comprising a suspension system having a base structure with at least one suspension point at a height suitable for suspending an article to be sintered; and a suspension element moveably connected to said suspension point for supporting said article to be sintered, wherein said suspension element itself forms a swing on which said article to be sintered is arrangeable.

Abstract: A method of manufacturing a honeycomb structure is disclosed wherein a green honeycomb body having a first contour is differentially altered such that the green honeycomb body has a second contour which is wider at a first end than at a second end. In one aspect, the altering is accomplished by removing a part of the green honeycomb body, such as with a removal tool. In another aspect, the altering is accomplished by exposing different regions of the honeycomb body to different drying environments.

Abstract: A method for controlling the shrinkage of ceramic formed bodies is provided, including performing a preliminary test to determine an average shrinkage of ceramic formed bodies made from test lots of a ceramic powder, and determining a linear correlation between the average shrinkage and measured amounts of the ground test lots removed from a ball mill during a specific milling time interval. A batch of the ceramic powder is then ground, an amount of the ground ceramic powder removed from the ball mill during the specific time interval is measured, and the linear correlation is used to estimate the shrinkage of a ceramic body made therefrom. The difference between a target shrinkage and the estimated shrinkage is determined, and one or more of the processing conditions used to form the ceramic body are changed to offset the difference.

Abstract: A method of producing a ceramic multilayer substrate involves producing a green composite laminate 11 containing first and second shrink-suppressing layers formed on the main surfaces of a green multilayer mother substrate 12 having a plurality of ceramic green layers 17 containing ceramic powder, the shrink-suppressing layers containing a sintering-difficult powder substantially incapable of being sintered under the sintering conditions for the ceramic powder; forming first grooves 16 extending from the first shrink-suppressing layer 13 side into a part of the multilayer mother substrate 12; firing the composite laminate 11; removing the first and second shrink-suppressing layers 13 and 14 and taking out the sintered multilayer mother substrate 11; and dividing the multilayer mother substrate 12 along the grooves 16, and obtaining a plurality of the ceramic multilayer substrates. Thereby, shrinkage in the plan direction at firing can be suppressed.

Abstract: A manufacturing method for producing ceramic item from a photocurable ceramic filled material by stereolithography. The method compensates for the anisotropic shrinkage of the item during firing to produce a dimensionally accurate item.

Abstract: To provide a production method of a polycrystalline ceramic body with excellent density, a preparation step, a mixing step, a forming step and a heat-treating step are performed. In the preparation step, a coarse particle ceramic powder, and a fine particle powder having an average particle diameter of ? or less of the average particle diameter of the coarse particle ceramic powder are prepared. In the mixing step, the coarse particle ceramic powder and the fine particle powder are mixed to produce a raw material mixture. In the forming step, the raw material mixture is formed to a shaped body. In the heat-treating step, the shaped body is heated and thereby sintered to produce a polycrystalline ceramic body. In the heat-treating step, a temperature elevating process and a first holding process are performed and at the same time, a second holding process and/or a cooling process are performed.

Abstract: A highly heat-conductive Si-containing material containing a Si phase whose lattice constant at room temperature is controlled at a level of more than 0.54302 nm but 0.54311 nm or less. Firing is conducted using a kiln material containing no B compound. With this highly heat-conductive Si-containing material and the process for production thereof, a reduction in heat conductivity can be prevented and a high heat conductivity can be exhibited stably.

Abstract: An exhaust filter system includes a particulate filter (PF) that is disposed downstream from an engine. The PF filters particulates within an exhaust from the engine. A heating element heats particulate matter in the PF. A fastener limits expansion movement of the heating element relative to the PF.

Abstract: A method for manufacturing an ultrahard compact includes assembling a mass of ultrahard material with a mass of substrate material such that the mass of ultrahard material extends radially outward a greater extent than the substrate material to compensate for a difference in the radial shrinkage of the ultrahard material compared to the substrate material during a sintering process. The method may further includes subjecting the assembled compact to a high pressure high temperature process that results in the forming of an ultrahard compact including an ultrahard layer integrally bonded with a substrate.

Abstract: A method for producing a ceramic substrate of the present invention includes a first process of providing holes in a shrinkage suppressing layer, a second process of filling the holes with a thick film material, a third process of laminating the shrinkage suppressing layer filled with the thick film material on an outermost layer of a ceramic substrate sintered in a preparatory process, followed by pressing, thereby obtaining a laminate, a fourth process of sintering the laminate, and a fifth process of removing the shrinkage suppressing layer. Thus, the kind of convex portions formed on the outermost layer of the ceramic substrate can be increased.

Abstract: A method of producing a ceramic multilayer substrate involves: producing a green composite laminate 11 containing first and second shrink-suppressing layers formed on the main surfaces of a green multilayer mother substrate 12 containing ceramic powder, the first and second shrink-suppressing layers containing a sintering-difficult powder substantially incapable of being sintered under the sintering conditions for the ceramic powder; forming first grooves 16 extending from the first shrink-suppressing layer 13 side into a part of the multilayer mother substrate 12; firing the composite laminate 11; removing the first and second shrink-suppressing layers 13 and 14; dividing the multilayer mother substrate 12 along the grooves 16 and obtaining a plurality of the ceramic multilayer substrates. Thereby, shrinkage in the plan direction at firing can be suppressed. Thus, a ceramic multilayer substrate having a high dimensional accuracy and a high reliability can be produced with a high production efficiency.

Abstract: To produce a green composite laminate 11, a green multilayer collective substrate 13 containing low-temperature sinterable glass ceramic powder as a main ingredient is disposed between first and second shrinkage-restraining layers 14a and 14b containing alumina powder as a main ingredient. Grooves 16 are formed on one main surface 11a of the green composite laminate 11 such as to pass through the first shrinkage-restraining layer 14a and the green multilayer collective substrate 13 and reach the second shrinkage-restraining layer 14b, but not to reach the other main surface 11b of the green composite laminate 11. The green composite laminate 11 provided with the grooves 16 is sintered under conditions where the low-temperature sinterable glass ceramic powder is sintered and the green first and second shrinkage-restraining layers 14a and 14b are removed to prepare a plurality of ceramic multilayer substrates.

Abstract: The invention relates to polymer ceramic composite materials with a virtually zero shrinkage compared to the original model after concluding partial pyrolysis and with a comparable thermal expansion behavior (preferably in an application range of 400° C. or less) to metal construction materials, in particular gray cast iron or steel, which are obtainable by methods described below; corresponding composite constructions and molded parts; and methods for producing and using these materials, composite constructions and molded parts. The polymer ceramic composite materials can for instance be used instead of or in contact with steel or gray cast iron temperature-proof molded parts, predominantly in mechanical engineering, without postmachining after the creative forming.

Abstract: A silica product, method and apparatus for manufacturing a tube-shaped silica glass product using a molded green body having a hollow rod structure. A molded green body having a hollow rod structure has a uniform outer diameter and has a bore having an inner diameter increasing gradually from one end to the other. When sintered in a vertically movable sintering furnace, a tube-shaped silica glass product having a longitudinal cross section distribution less than a tolerance limit may be obtained. Optical fiber manufactured using the silica glass tube according to the present invention may have a uniform longitudinal geometrical structure, thereby exhibiting superior transmission characteristics.

Abstract: A ceramic membrane for a capacitive vacuum measuring cell includes a thin ceramic membrane with a thickness of <250 &mgr;m, in particular less than 120 &mgr;m. The membrane is produced from a ribbon-shaped green body of Al2O3, and is given high planarity by smoothing the membrane after sintering. The green body is sintered at a sintering temperature that is higher than the smoothing temperature applied following sintering.

Abstract: The present invention provides a laminated body, comprising: a first sheet layer comprising an aggregate of a first powder, at least a part of the first powder being in a sintered state; a second sheet layer disposed so as to make contact with the first sheet layer and comprising an aggregate of a second powder, the second powder being in a non-sintered state; and the first powder and the second powder being solidified to each other by allowing a part of the first sheet layer material to diffuse or to flow into the second sheet layer.

Abstract: A procedure is provided for bringing an incompletely densified cast radome to a desired final or near final shape through the use of one or more conformal tools during a high temperature firing operation. A conformal firing tool is defined in this case as a mandrel or mold made from a high temperature material, such as a graphite composite, that represents the desired shape of the finished radome. The process consists of firing the cast radome body over a mandrel, or inside a mold, or in combination with the two, such that the tools impart a desired dimensionality to the cast part as it densities and flows at high temperature.

Abstract: Flexible setter powder deposition sheets containing setter powders were developed for sintering of ceramic articles including tapes by an economical, fast and simple method. The sheets provide for deposition of a thin and uniform layer of setter powders on a green ceramic article after burnout of a binder in the sheet. Because of high strength and low burnout temperature, hydroxypropyl methylcellulose binder is preferred for production of these sheets. Tape cast sheets with low solids loading can be obtained by optimizing the wetting behavior of aqueous slurries on tape carrier. Setter, powder deposition sheets are of particular benefit in processing of thin ceramic tapes, particularly for processing of piezoelectric ceramic tapes. Tapes can be processed in a sandwich formed by layering setter powder deposition sheets between tapes and cover plates employed to maintain tape flatness and to reduce evaporation of volatile components of the ceramic.

Abstract: The invention utilizes green support structures during sintering to maintain the shape, reduce sagging and prevent separate part sections from coming into contact and fusing together during the sintering process. In the most preferred embodiment, monolithic green structures are form with integrated support green structures that are released from the parts after sintering. Preferably monolithic green structures are formed by the Mold Shape Deposition Manufacturing (Mold SDM) process. By the method described, complex sintered structures can be made having interlocking and independently movable interlocking parts.

Abstract: A method for making multilayer ceramic substrates having substantially reduced planar shrinkage and distortion resulting from the firing or sintering process. Contact sheets are employed in the fabrication process on the surface of the multilayer ceramic substrate to be fired with the contact sheets being prepared from a composition containing a non-sinterable non-metallic inorganic material such as alumina having an average particle size approximately about 1 micron or less and an organic binder and preferably a plasticizer. In a preferred embodiment of the invention, the multilayer structure to be fired containing the contact sheet of the invention is provided with a beveled or chamfered edge at an angle of greater than about 60 degrees. A fabrication process employing only chamfering of the edge or the use of a contact sheet of the invention also provides improved multilayer ceramic substrate products.

Abstract: A method of manufacturing a ceramic arc chamber (420) comprising providing a sintering tray (412) including a plurality of bores (422). The bores (422) having a first diameter upper section (424) and a second narrower diameter lower section (426). Positioning a plurality of ceramic end caps (212) having a main body portion (216), and a leg portion (219) in the bores (422) such that the leg portion (219) passes downwardly through the narrower diameter lower section (426) and the main body portion (216) is retained within the upper section (424). Moreover, the second diameter lower section (426) acts as a shoulder supporting the end cap (210). Next, a ceramic arc tube (214) is positioned within the first diameter upper section (424) and mated with the ceramic end cap (212). A second end cap (210) is mated to a second upper open end of the ceramic arc tube (214) to form an arc tube preform (420). The arc tube preforms (420) are then sintered to join the components via controlled shrinkage.

Abstract: A method for producing a dental prosthesis to be fitted to a fitting member including the steps of: determining the three-dimensional contours of the fitting member; producing a three-dimensional form of the dental prosthesis; producing a working stump and/or a working pack; placing the working stump in the form and/or packing the working pack around the outside of the form to completely cover the form; sintering the form with the working stump and/or the working pack; and separating the working stump and/or the working pack from the dental prosthesis after sintering. The working stump and working pack are produced such that they are enlarged by a predetermined enlargement factor.

Abstract: A joint body containing a ceramic member composed of a main body and a disclike projection projected therefrom and a ceramic cylindrical body. The disclike projection is inserted inside the cylindrical body, and a relative density of the disclike projection is higher than that of the cylindrical body. The cylindrical body is composed of a straight portion not contacted with the projection and having a uniform inside diameter, a diameter-expanded portion in contact with the projection and having the largest inner diameter, and a tapered connecting portion bridging the straight portion and diameter-expanded portion. A difference between the inner diameter of the straight portion and that of the diameter-expanded portion is 0.05 mm to 0.6 mm.

Abstract: A method for producing a long ceramic body, including the steps of pre-firing a non-fired long ceramic body at a first temperature for a sufficient time to achieve a shrinkage ratio in the body of 5% to 95%, thereby forming a pre-fired ceramic body, hanging the pre-fired ceramic body in a substantially vertical direction inside a sheath while maintaining a spacing between the pre-fired ceramic body and the sheath, applying a downward load to the pre-fired ceramic body at a position proximate the bottom end thereof, and firing the pre-fired body at a second temperature for a sufficient time to sinter the pre-fired ceramic body.

Abstract: A method for sintering tube pre-forms in an furnace for obtaining ceramic tubes which are extremely straight is provided, in which, during sintering, the tube preforms are placed inside supporting tubes in ceramic material, the support tubes 1 containing the tube preforms being arranged parallel to each other forming stacks 7 of layers 3 supported by support plates 4 in a refractory material, the inside surface of the support tubes being out-of-true by less than 0.1 mm over a length of 90 mm.

Abstract: The present invention relates generally to a new apparatus and method for screening using porous backing material. More particularly, the invention encompasses an apparatus that uses a porous backing material which is adhered to a green sheet during the screening process. Basically, a backing layer having a very high porosity is adhered to a green sheet, while the green sheet is screened. During the drying process of the green sheet some of the screening fluids are absorbed by the porous backing layer, which allows the screened vias of the green sheet to have a smooth surface.