Abstract: A process for the production of a porous ceramic mold is described, compsiging adding about 40 to 60 parts by weight of water to 100 parts by weight of a ceramic material, mixing the thus-formed ceramic slurry with about 20 to 40 parts by weight of a hydrophilic urethane prepolymer having a free isocyanate group content of from about 4% to 7% by weight, reacting and foaming the resulting mixture after the introduction thereof into a mold, drying the thus-formed foamed urethane molded article, and combusting very slowly and sintering the dried foamed urethane molded article to produce a porous ceramic molded article.

Abstract: The method concerns forming a relatively stable slip of silicon metal particles and yttrium containing particles. In one embodiment, a casting slip of silicon metal particles is formed in water. Particles of a yttrium containing sintering aid are added to the casting slip. The yttrium containing sintering aid is a compound which has at least some solubility in water to form Y.sup.+3 ions which have a high potential for totally flocculating the silicon metal particles into a semiporous solid. A small amount of a fluoride salt is added to the casting slip which contains the yttrium containing sintering aid. The fluoride salt is one which will produce fluoride anions when dissolved in water. The small amount of the fluoride anions produced are effective to suppress the flocculation of the silicon metal particles by the Y.sup.

Abstract: The disclosed ceramic rotor comprises integrally formed blade portions made of ceramics sintered at atmospheric pressure and a blade-holding portion to which said blade portions are integrally cemented by ceramic material. The blade-holding portion is made of ceramics sintered at atmospheric pressure and has a larger density than that of the blade portions. The thickness of the blade-holding portion is not smaller than the thickness of the blade portions but smaller than the distance between the front and rear surfaces of the blade portions. In the disclosed process, bodies of the blade portions and the blade-holding portion are separately formed and coupled by applying ceramic material therebetween, and the coupled bodies are sintered at atmospheric pressure to produce the ceramic rotor.

Abstract: Rigid shaped articles of expanded inorganic aggregate, such as expanded perlite, bonded with calcium silicate hydrate and preferably reinforced with fibers, are made by mixing a hydrothermally reacted gel of calcium silicate hydrate crystals with the expanded aggregate, shaping and drying, without treatment with saturated steam after the gel and aggregate have been mixed.

Abstract: Composite inorganic articles are produced by bringing two separate inorganic slurries, each containing different ceramic materials, into contact with each other, simultaneously freezing the slurries while in contact with each other to form a unified frozen structure, thawing and drying the structure, and firing the unified structure.

Abstract: A calcium silicate shaped product is produced by forming an aqueous slurry of calcium silicate hydrate obtained by reacting a calcareous source with a siliceous source dispersed in water under heating; molding said aqueous slurry and heat-treating said molded product under the condition providing the equations (I) and (II);100.ltoreq..theta..multidot.T (I)50.ltoreq..theta..ltoreq.300 (II)wherein .theta. represents a temperature of the inner part of the molded product (.degree.C.) and T represents a time (hour) and providing a percent water loss of the treated molded product of less than 25 wt. %, before drying or steam-curing and drying the molded product.

Abstract: Novel thin flexible decorative colored cementitious veneers of about 5 to 60 mils in thickness, useful in wall coverings, floor coverings and on ceilings; and methods of producing said thin decorative cementitious veneers wherein printing, embossing and casting are performed simultaneously. The basic method comprises the steps of placing a wet cloth on a mold engraved with a design followed by placing a plastic cement mix on said wet cloth to simultaneously form a casting and a temporary cloth mold which is the exact copy of the original mold, immediately removing the plastic cement casting together with the temporary cloth mold from the original engraved mold before it sets, thereby making the original mold immediately available for the next casting, removing the temporary cloth mold from said plastic cement casting before it sets, and air curing said casting while being stored.

Abstract: A fluid-release mold is disclosed. The mold includes a preformed, porous mold body having a mold face formed on a first exterior surface and a second surface. A groove is formed in the second surface. A tape covers the groove to form a conduit between the surface of the groove and the surface of the tape facing the groove. The conduit directs pressurized release fluid to the mold. A fluid impermeable backing material is disposed over the second surface of the mold body whereby egress of the fluid from the conduit is prevented except through the mold body in a direction away from the second surface.

Abstract: Ceramic shapes having impermeable tungsten coatings can be used for containing highly corrosive molten alloys and salts. The shapes are prepared by coating damp green ceramic shapes containing a small amount of yttria with a tungsten coating slip which has been adjusted to match the shrinkage rate of the green ceramic and which will fire to a theoretical density of at least 80% to provide a impermeable coating.

Abstract: A method of making a thermal-insulating panel for use in an electric furnace. A refractory fiber mat is formed in a felting box from a suspension of discrete refractory fibers plus an inorganic bonding agent. The modules have a hot face, a cold face and a plurality of side faces. A plurality of individual ceramic supports are partially embedded in said mat and protrude outward from the hot face. The embedded portions are shaped so as to be firmly anchored within the mat, and the protruding portions are shaped to support an electrical resistance heating ribbon in the interior of the furnace.The modules are preferably formed in a special felting box having a front wall that has a plurality of cavities from which the ceramic supports extend horizontally into the main portion of the box. The layers of fibers build up upon the bottom screen in planes perpendicular to the hot face of the module.

Abstract: The in-line transmission of a translucent polycrystalline alumina arc tube for a high-pressure sodium discharge lamp is improved by as much as 50% by dipping the "green" tubular compact in an aqueous slurry containing finely-divided alumina particles and, after the slurry-dipped compact has been dried, subjecting it to the usual pre-sintering and sintering operations required to convert the compact into a dense ceramic body. The slurry is preferably prepared from the same slurry which contains the blended alumina powder, magnesia and other additives that comprise the raw-mix slurry which is spray-dried to produce the larger size generally spherical particles that are compressed or extruded to form the green compact.

Abstract: A method for making metal fiber reinforced concrete block which comprises formimg a mix of aggregates to which metal fibers and the cement are added. Water is added to the mix to form a mixture which is poured into a mold having two parallel spaced apart surfaces. A stripper is advanced through the mold and frictionally engages the inner surfaces of the two parallel walls and removes the concrete block.

Abstract: Multifilament fibers of alumina are fabricated into a multi-directional preform which is densified through repeated infiltration with an aqueous solution of colloridal alumina, dried and fired.

Abstract: A method is provided for making a cement composite product such as a flat or profiled sheet, or a pipe, containing glass fibre as reinforcement instead of the traditional asbestos, wherein a cement and water slurry of flowable consistency is made with high shear agitation, the glass fibre is mixed with the slurry in a static mixing apparatus (i.e. having no moving parts) by bringing together flows of the slurry and of the glass fibre and then altering the path of the conjoined flow, and the glass fibre-containing mixture is immediately subjected to the conventional deposition on a water-permeable web, formation of a profile if desired, drainage of the water from the slurry through the web, and curing the deposited cement to form the product.

Abstract: A calcium silicate shaped product is prepared by forming an aqueous slurry of calcium silicate hydrate by reacting a calcareous source with a siliceous source in water as a dispersion under heating; molding said aqueous slurry to form a molded product having a bulk density of less than 0.6 g/cm.sub.3 ; curing said molded product, in a closed tank having a capacity of 1.5 to 30 times of the volume of said molded product at 140.degree. to 300.degree. C. by dry-heating without feeding steam, and drying the product.

Abstract: A novel method of making a solar collector is disclosed and described. The solar collector includes a base and a plurality of upstanding walls extending about the perimeter of the base. An input and an output extend through the walls to communicate with a plurality of liquid conduits integral with the base. A transparent cover is secured to the upstanding walls for covering the base and the plurality of conduits. The conduits and the base are constructed of a one-piece molding of a curable material. The invention resides in the method of forming the solar collector through a molding process. A first and a second mold element are positioned relative to one another to form a mold cavity defining the outer configuration of the solar collector. The mold cavity is completely filled with a curable material. The curable material is allowed to cure only adjacent the mold cavity wall whereafter the mold cavity is drained of the non-cured material thereby creating the internal configuration of the solar collector.

Abstract: Ceramic products are produced containing a network of glass filaments having a hydrophilic surface. This network of filaments aids the transfer of water from the center of wet ceramic bodies to the surface thereof to speed up dewatering of slip cast materials while in the mold to thereby permit increased production from the molds. In addition, the fibers speed up oven drying of the green ware to give a further increase in production.

Abstract: The invention provides an improved method for producing plate-shaped or tape-shaped silicon crystal bodies having pillar-like structures therein which are equivalent to columnar structures comprising conducting the sintering process, for purposes of particle enlargement, in a gas atmosphere comprised of argon and a minimum amount of hydrogen. In a preferred embodiment, the hydrogen concentration in such atmosphere is about 6% by volume. The so-produced silicon bodies are useful for further processing into large-surface solar cells.

Abstract: A method of manufacturing a sintered permanent magnetizable body essentially consisting of a ferrite of the formula MeO.6Fe.sub.2 O.sub.3, wherein Me is at least one of the metals barium, strontium and lead by adding an acid to a suspension of the powdered ferrite in a liquid which suspension is then supplied to one or more matrices of a press to form a compressed product which is then sintered. As a result of the treatment with acid, the compression time is reduced.

Abstract: Dense, essentially flawless, complex refractory or metal shapes are formed by preparing a casting slip of fine refractory or metal powder wherein the slip liquid preferably contains 0.1 to 10% by weight of a hydrogen bond forming compound, casting the slip, freezing the cast slip, removing the solid form from the mold, drying, and finally firing to sinter the refractory or metal particles.

Abstract: A slip-casting system utilizing a ceramic powder for the mold. The system facilitates casting thin-walled and/or long objects without additives for demolding.

Abstract: A method of moulding magnet compacts in a die surrounded by an induced magnetic field, the die being surrounded by a mass of material having a high magnetic conductivity so that the induced magnetic field is non-linear through the die.

Abstract: A method and apparatus for heat forming hardboard and other types of forming board including the steps of placing a mesh screen in a die between upper and lower platens having mating contours, placing a sheet of heat formable board in the die upon the screen and below the upper platen, pressing the platens together and heating the sheet such that the sheet and screen are formed to the mating contours and gases and vapors released from the sheet follow the contours of the screen to escape from the die, separating the platens, and removing the sheet from the die.

Abstract: To permit use of less expensive iron powder material and manufacture of more complex shapes, a mixture of iron powder, of an approximate grain size of between 30 to 450 .mu.m, and containing preferably 5 to 50% of carbonyl iron powder or from 5 to 50%, by weight, of soft ferrite powder of a grain size of from 10 to 200 .mu.m, and a thermosetting resin, in which the thermosetting resin is about 50% by volume of the overall mixture, is filled into a die. Pressure is built up in the die, which is heated, permitting excess binder to escape during the build-up phase thereof, the pressure then being held so that the resin can set in the heated die. The pressures needed are substantially less than heretofore required, in the order of from between 500 to 5000 bar.

Abstract: Method for slip casting toilet bowls and as mould for casting ceramic material in slip form, including a compartment having an air impermeable wall and arranged, in the casting position of the mould, so that when the mould is filled with slip air is trapped in the compartment. The compartment is located at a region where casting is not to occur and the trapped air not only achieves this but also prevents the surface of the compartment from becoming wetted, thereby making subsequent cleaning easier. The compartment may be formed either in a plaster mould part and its surface rendered air impermeable, or in a separate part made of air impermeable material, and assembled with the plaster mould parts. The mould is particularly suitable for casting a water-closet bowl, the compartment being located at the region where the open top of the bowl is formed.

Abstract: A method of making a silicon nitride part is disclosed. In this method an article of silicon nitride is first made which has a density less than the theoretical density of silicon nitride. This article also contains a densification aid. The entire surface area of this article is coated with a thin silicon nitride skin which is gas impervious. The so coated article is heated to a temperature for a time sufficient so that some of the densification aid may diffuse into the silicon nitride skin. The so treated article is then subjected to a pressure sufficiently high, for a time sufficiently long and at a temperature which permits the silicon nitride article and skin thereon to be compacted to increase the density of the article to a density greater than it originally had and to form the silicon nitride skin about the article so that the skin becomes an integral of the finished part.

Abstract: An aqueous slurry of calcium silicate hydrate which is formed by heating a siliceous source and a calcareous source in water to react them and which has the specific property is shaped with a press filter molding and cured by a steam curing under steam pressure to cause a transformation of the calcium silicate hydrate whereby a calcium silicate shaped product having low bulk density and high mechanical strength is obtained. The calcium silicate shaped product is suitable as a lagging product or a heat insulator.

Abstract: An illustrative embodiment of the invention provides a technique for applying the deep heat capabilities of microwave energy to the problems of ceramic ware production. A plaster-of-paris mold, filled with "slip" is exposed to microwave energy to produce a "green body" in a few minutes. After excess "slip" is decanted and the "green body" is exposed, the mold is dried through microwave heating, weighed and then brought up to the proper degree of moisture by spraying and weighting. The "green body", moreover, after finishing is further dried through microwave heating.

Abstract: A method of making a multi-layer ceramic substrate for an integrated circuit device package having internal circuitry by forming a plurality of porous ceramic bisque sheets, impregnating the pores of the bisque sheets with an organic binder material, forming openings through the impregnated bisque sheets, filling the openings with conductive material and imprinting conductive circuitry patterns on the surface of the impregnated bisque sheets of a conductive material, assembling the plurality of apertured printed impregnated bisque sheets into a laminated unit, and sintering the laminated unit to form a unitary laminated structure having an interconnected internal circuitry system.

Abstract: A method of densifying a reaction bonded silicon nitride article is disclosed. In accordance with the broadest principles disclosed, a densification aid is incorporated into a reaction bonded silicon nitride article. The so-made reaction bonded silicon nitride article is enclosed in a chamber which also contains a mixture of silicon nitride powder and powder the same as the densification aid incorporated into the reaction bonded silicon nitride article. The reaction bonded silicon nitride article, and the powder mixture associated therewith, is subjected to a nitrogen gas pressure sufficient to prohibit a significant volatilization of silicon nitride at a sintering temperature. The reaction bonded silicon nitride article, the powder mixture and nitrogen gas associated therewith are heated to a temperature above 1700.degree. C. for a time sufficient to permit sintering of that article whereby the strength of the reaction bonded silicon nitride article is increased.

Abstract: A ceramic unit for indirect heat exchange, said unit being formed by extruding raw ceramic material in a parallel duct configuration, piercing a first series of inlet and outlet orifices for a fluid at the ends of a first series of ducts, the axes of said orifices being perpendicular to those of the ducts, and firing the unit. The inlet orifices (5) and/or the outlet orifices (9) are formed by making oblique cuts (7,10) on the ends of the rows of ducts to provide inlet or outlet openings perpendicular to the common direction of the ducts and then closing off the ends of the obliquely cut rows. Application to heat exchangers for turbine engines.

Abstract: Process for producing a high-strength, rotationally-symmetrical component by appending short fibers of glass, carbon or aramid in an organic solvent, and depositing the fiber material in a rotating sieve-like receptacle through a radially movable nozzle. The produced preform is impregnated with a matrix of resin and hardener and pressed into its final shape.

Abstract: A method of forming a slip cast article having at least one zone of cellular construction is disclosed. The method may be utilized to make articles having zones of different cellular size as well as articles having zones of cellular construction adjacent zones of noncellular construction. In its simplest form, the method is carried out by providing a slip casting mold which has a casting volume formed therein. A stabilized casting slip is poured into the casting volume. The pH of the stabilized casting slip is increased until a hydrolysis reaction takes place between the water forming the vehicle and an oxidizable metal forming the casting material. This hydrolysis reaction results in the evolution of gases, some of which are trapped within the slip to develop a zone of cellular construction. The greater the increase in pH, the more vigorous is the hydrolysis reaction and the resulting cellular construction has larger sized cells.

Abstract: Method and apparatus for producing silicon nitride molded bodies by means of a pseudoisostatic hot pressing process. Silicon nitride is initially ground in a grinding vessel with grinding elements wherein the vessel is lined with the same material from which the grinding elements are made, e.g., hot pressed silicon nitride. Grinding is continued until a specific surface area greater than 15 m.sup.2 is obtained. The grinding takes place in the presence of a grinding liquid to prevent oxidation of the freshly ground silicon nitride. The silicon nitride suspension is then treated in a pressure vessel to remove the grinding liquid therefrom and form a blank. The blank is thereafter embedded within a pressure transfer medium, e.g., boron nitride, and inserted into the die of a hot pressing furnace to obtain the desired hot pressed silicon nitride.

Abstract: A rotatable carriage for supporting split-type plaster molds for molding ceramic hollowware is disclosed, in which the molds are retained between two frames rotatable to a succession of positions in which the molds are retained in place between the framework of one of said frames and a dual cell inflatable member on the inner face of the other of said frames. The first of said frames includes a retaining member engaging the outer surface of said mold to prevent said mold from slipping relative to said frames. A new casting method is disclosed in which the slip is poured from the filled molds in at least two steps with the rotatable frames being rotated to a different position for each of said pouring steps.

Abstract: A process for forming a solid layer of intumescent material from a fluid material which comprises the steps of pouring the fluid material onto a mold and evaporating the liquid from the fluid material while the fluid material is contained within a chamber offering a predetermined restraint to the escape of vapor from the chamber to the ambient atmosphere.

Abstract: An aluminum oxide-aluminum nitride composite electronic substrate with anisotropic thermal properties is described. The aluminum nitride is in the form of needles incorporated into the aluminum oxide, the needles being oriented or aligned through the thickness of the substrate parallel to the short transverse direction of the substrate. The substrate has improved thermal conductivity in the short transverse direction and yet maintains good dielectric strength across the surface of the substrate. The improved thermal conductivity is required for heat dissipation from the micropackage assembly.

Abstract: A cross flow filtration molding apparatus and method are disclosed which are particularly useful for forming complicated shapes from dispersions of particles in a liquid medium. Dispersion is pumped through a mold which has porous walls and a sufficient pressure differential is applied to drive a portion of the liquid medium through the porous walls which results in deposition of particles on the walls to form a shaped article. The shaped article may inherently have sufficient structural integrity, or it may be post-treated to provide additional structural integrity.

Abstract: A porous sintered tile is formed of lithium aluminate for retaining molten lectrolyte within a fuel cell. The tile is prepared by reacting lithium hydroxide in aqueous solution with alumina particles to form beta lithium aluminate particles. The slurry is evaporated to dryness and the solids dehydrated to form a beta lithium aluminate powder. The powder is compacted into the desired shape and sintered at a temperature in excess of 1200 K. but less than 1900 K. to form a porous integral structure that is subsequently filled with molten electrolyte. A tile of this type is intended for use in containing molten alkali metal carbonates as electolyte for use in a fuel cell having porous metal or metal oxide electrodes for burning a fuel gas such as hydrogen and/or carbon monoxide with an oxidant gas containing oxygen.

Abstract: Method and apparatus for the manufacture of molded bodies from sludges in which a plurality of sludges having different average particle sizes are subjected sequentially to filtration and dehydration in a mold to build up the molded body.

Abstract: A process and composition for treating glass fibers for use as reinforcement of cementitious materials. The glass fibers are first sized with a size composition containing cationic fiber forming organic polymer and then a second coating containing an anionic film-forming organic polymer is applied to the glass fibers whereby the cationic and anionic polymers react to form a thin film on the glass fiber surfaces. The resulting glass fibers have good wetting and dispersibility characteristics for use as reinforcement of cementitious materials.

Abstract: A gypsum moldings as building materials having high strength is obtained by use of fibrous .alpha.-calcium sulfate hemihydrate as a raw material.There are two methods manufacturing the said gypsum moldings. One of them is the wet method and the other is the dry method.The wet method essentially consists of mixing fibrous .alpha.-calcium sulfate hemihydrate suspension with reinforcers et al., papering and dehydrating the resulting mixed suspension, with or without pressing the resulting wet mat, curing and drying the mat to obtain a gypsum moldings as building materials having high strength.The dry method is roughly divided into two methods. One of them comprises adding water to fibrous .alpha.-calcium sulfate hemihydrate and molding the resulting wet hemihydrate, and the other comprises molding fibrous .alpha.-calcium sulfate hemihydrate and adding water to the resulting moldings.

Abstract: To calcium lignin sulfonate is added a formulation of ammonium or sodium linear alcohol ether sulfate in a ratio to form an additive to calcined gypsum slurry which will reduce the water requirement and the heat needed to cure the wallboard made from the slurry.

Abstract: The water resulting from the filter press molding of slurries of hydrated lime and reactive silica in the manufacture of hydrous calcium silicate products is recycled to the process by treating it with carbon dioxide to precipitate dissolved calcium hydroxide, filtering, and returning the filtered water to the process step wherein the lime and silica are slurried in water.

Abstract: A method of forming a slip cast article is disclosed. The slip cast article is formed in a casting volume of a forming mold, which mold has a portion thereof formed of a meltable organic material. The vehicle of the casting slip used to form the article is drawn off to a level which provides a consolidated casting in the casting volume which contains sufficient vehicle that the casting is resistant to shrinkage. The consolidated casting and the organic mold portion are then surrounded with a porous, liquid drawing media. A high humidity of the vehicle of the casting slip is maintained about the consolidated casting surrounded by the porous, liquid drawing media. The consolidated casting and surrounding liquid drawing media are heated while the high humidity of the vehicle is maintained to a temperature which causes the meltable organic material to melt. The porous, liquid drawing media then draws the melted material away from the consolidated casting.

Abstract: An article is cast from a composition comprising a binding agent containing, by weight, from 90% to 10% calcined gypsum and from 10% to 90% Portland cement mixed with water to produce a fluid mixture which is caused to flow into a mould or other supporting device and is there allowed to set. To increase the durability of the cast article in the presence of moisture, sodium carbonate in an amount up to 5% by weight of the dry weight of the cement is added to the composition. The sodium carbonate is preferably present in an amount between 0.1% and 0.5% of the dry weight of the cement and the composition preferably also contains an acrylic resin emulsion in an amount from 0.25% to 4% of the dry weight of the gypsum and cement in the composition and a pigment such as iron oxide, titanium oxide or cobalt oxide in an amount from 0.25% to 4% by weight of the dry weight of the gypsum and cement in the composition.

Abstract: A composite solid electrolyte material for use in oxygen sensors, which comprises a mixture of at least two ceramic constituents, one of which is a good oxygen ion conductor and the other a non-electrolyte, is useful for oxygen sensor fabrication. Particularly, it enables gas analysis oxygen sensors to be produced by conventional techniques because the coefficient of thermal expansion of the composite electrolyte material can be closely matched to the material of a supporting sensor body. The closeness of thermal expansion coefficients means that oxygen sensors can now be formed in the "green" state, then fired.

Abstract: An aqueous slurry of calcium silicate hydrate which is formed by heating a siliceous source and a calcareous source in water to react them and which has the specific property is shaped with a press filter molding and cured by a steam curing under steam pressure to cause a transformation of the calcium silicate hydrate whereby a calcium silicate shaped product having low bulk density and high mechanical strength is obtained. The calcium silicate shaped product is suitable as a lagging product or a heat insulator.

Abstract: A high strength and serrated edge extended leakage path ceramic tube wall r high voltage tube device, such as a proximity focused image intensifier, and method of making same. The ceramic may be comprised of a ceramic particle slurry made of high density alumina in a glass binder wherein the slurry is ultrasonically compacted against ultrasmooth mold walls in the uncured state. The mold may be formed by using a highly polished preshaped, positive, made of a metal such as brass, and then removing the positive. The mold may be further processed by electrodepositing a metal, such as nickel or nickel alloys, onto the positive to produce an ultrasmooth surface. The mold may be made of a vinyl polymer type thermoplastic. The inside of the mold takes up the smooth surface characteristics of the positive that is, in turn, transferred to the uncured ceramic when sufficiently pressed and compacted by the ultrasonically compacting step. The uncured ceramic is then pre-baked at about 350.degree. C.

Abstract: Polymers are isolated from their dispersions in liquid media in a twin-screw extruder, wherein the screws in the feed area are intermeshing and fully wiping each other and the extruder bore, the polymer dispersion or latex (which is coagulated in the first zone) being conveyed to a high pressure seal zone, liquid being forced upstream and out of the extruder, and the polymer being conveyed through the seal, into a reduced pressure zone, where most remaining liquid is removed, and finally into a pumping zone from which it is extruded. The invention avoids high pressure pumping of polymer dispersions and also is applicable to dispersions of sticky thermoplastic or elastomeric materials, which have caused considerable difficulties in the past.