Abstract: Uniformity of the interstitial distribution of the second phase within composite superconducting high T.sub.c ceramic compositions is achieved by infiltrating the second phase from a bath of molten, low melting point, surface wetting, metallic salt introduced after the ceramic microstructure is formed and the superconductor phase fully developed. The metal or metal oxide second phase is formed uniformly in situ by the decomposition of the infiltrated salt and liquification and/or sintering of the residual metal or metal oxide.

Abstract: In order to provide a mixed oxide ceramic sintered body having no defect such as void and pore, and high strength, toughness and reliability, a mixed oxide of rare earth oxide-alumina oxide added with silica is fired with a non-oxide mixture of SiC and/or Si.sub.3 N.sub.4. In the production method, the crystal grain size of the sintered body is controlled to not more than 30 .mu.m, and abnormal grain growth and occurrence of pore can be restrained to easily produce a practically usable mixed oxide ceramic sintered body having excellent toughness inherent to oxide sintered body and excellent high-temperature strength inherent to SiC and Si.sub.3 N.sub.4 and uniform structure.

Abstract: The invention concerns self-supporting ceramic structures, including ceramic composite structures embedding a filler, and methods of making them. The ceramic structures comprise a polycrystalline material made by oxidation of a body of molten parent metal with an oxidant. The polycrystalline material has a first region substrate surmounted by a terminal region stratum which is integral with the first region. The terminal region stratum which is harder and of denser, finer crystalline structure than the first region substrate and is formed in a reaction stage subsequent to the reaction stage in which the first region of polycrystalline material is formed. Growth of the first stage is attained by by attenuating or interrupting the transport of molten parent metal to the first region under conditions which nonetheless leave or maintain therein enough oxidizable molten parent metal to form the polycrystalline material of the terminal region.

Abstract: A method of producing an electrocast brick or other ceramic shape, and the ceramic shape produced thereby, wherein the electrocast brick or other ceramic shape is cast in a mold which is formed, with a predetermined cavity shape and size, of quartz glass particles; the ceramic material of the ceramic shape may be Al.sub.2 O.sub.3 -ZrO.sub.2 -SiO.sub.2 ceramic, Al.sub.2 O.sub.3 -SiO.sub.2 ceramic or other heat meltable ceramic materials.

Abstract: Disclosed is a phenol-formaldehyde resin binder for refractories, having from 0.05 to 0.6 methylol group on average per one phenolic constitutive unit and having a free phenol content of less than 5%. For producing refractory granules with the binder, a composition comprising carbon substances of 50% by weight or less in all and a balance of refractory substances is kneaded with the binder and water optionally along with a solvent having a boiling point of 200.degree. C. or higher, in a mixer as heated at 60.degree. to 130.degree. C. Optionally, the volatile content in the blended mix is adjusted to the shapable level. The process of using the binder is free from injury to human bodies and the danger of firing. The refractory granules may be shaped into refractory articles having a suitable gas-permeability stable against variation of the working environment. The refractory granules are suitable for shaping gas-blowing immersion nozzles having a suitable gas-permeability.

Abstract: In ceramic welding processes, oxidizing gas and a mixture of refractory and fuel powders are projected against a surface and the fuel is burnt to generate sufficient heat that the refractory powder becomes at least partially melted or softened and a cohesive refractory weld mass is progressively built up against that surface. In order to reduce any tendency for the weld mass to include a low-grade refractory phase and thus promote the refractoriness of that weld mass, the fuel powder is present in a proportion of not more than 15% by weight of the total mixture and includes at least two metals selected from aluminum, magnesium, chromium and zirconium, in that at least the major part by weight of the refractory powder consists of one or more of magnesia, alumina and chromic oxide, and in that the molar proportions of silica and calcium oxide present in the refractory powder (if any) satisfy the following expression:molar concentration of SiO.sub.2 in %.ltoreq.0.2+molar concentration of CaO in %.

Abstract: A method of producing heavy metal carbides of high specific surface area characterised in that a compound in the gazeous state of said heavy metal is caused to react with reactive carbon having a specific surface area at least equal to 200 m.sup.2.g.sup.-1 at a temperature comprised between 900.degree. and 1400.degree. C., and thus obtained carbides.

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 green tinted, ultraviolet absorbing glass is disclosed having a standard soda-lime-silica base glass composition and a colorant portion consisting essentially of on a weight basis: less than 2.0% total CeO.sub.2, V.sub.2 O.sub.5, TiO.sub.2 or MoO.sub.3 and greater than 0.7% total iron (expressed as Fe.sub.2 O.sub.3) with the ratio of FeO/total iron less than 0.35.The glass reduces the amount of costly cerium required to yield low ultraviolet transmittance, viz., no greater than 31 percent (300 to 390 nanometers) at a reference thickness of 3.9 millimeters.

Abstract: Compositions consisting essentially of molybdenum disilicide, silicon carbide, and a zirconium oxide component. The silicon carbide used in the compositions is in whisker or powder form. The zirconium oxide component is pure zirconia or partially stabilized zirconia or fully stabilized zirconia.

Abstract: A carbon-containing black glass has the empirical formula SiC.sub.x O.sub.y wherein x ranges from about 0.5 to about 2.0 and y ranges from about 0.5 to about 3.0 and is resistant to oxidation up to a temperature of about 1400.degree. C. The black glass is synthesized by heating a spirosiloxane polymer in a non-oxidizing atmosphere up to a temperature in the range of from about 750.degree. C. to about 1400.degree. C. The polymers are synthesized by reacting the spirosiloxane oligomers: ##STR1## wherein a and b are integers from 0 to 20, preferably 1 to 5, c and d are integers from 2 to 20, preferably 2 to 6, m is an integer from 0 to 10, preferably 0 to 4, and wherein for each silicon atom in the oligomer having R and R' moieties, R is independently selected from the group consisting of alkyl groups from C.sub.1 to C.sub.20, preferably C.sub.1 to C.sub.5, and R' is independently selected from the group consisting of hydrogen, and alkenyl groups from C.sub.2 to C.sub.20, preferably from C.sub.2 to C.sub.5.

Abstract: There are disclosed an organophilic clay which comprises a hydroxypolyoxyethylenealkyl ammonium ion represented by the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 may be the same or different, and each represent a (CH.sub.2 CH.sub.2 O).sub.n H group (where n is 2 or more, preferably 2 to 20), a hydrogen atom or an alkyl group having 1 to 30 carbon atoms, provided that one to three of R.sub.1 to R.sub.4 is/are a (CH.sub.2 CH.sub.2 O).sub.n H group(s) and at least three of R.sub.1 to R.sub.4 are (CH.sub.2 CH.sub.2 O).sub.n H group(s) and alkyl group(s),being introduced in interlayers of an expandable layer silicate, a method for preparing the same and a gellant for a high polar organic solvent.

Abstract: A painted elastomeric component capable of withstanding temperatures within the range of at most 32.degree. F. and at least 500.degree. F. and having good flexibility and reflectivity of heat and capable of deformation without damage to the paint. The elastomeric component has a painted surface. The coating of paint covering the painted surface includes about 100 parts by weight of a room temperature vulcanizing sealant, about 300 to 1,000 parts by weight of an aromatic or aliphatic solvent and about 20 to 200 parts by weight of metallic particulate material.

Abstract: In a spark plug insulator having a sintered ceramic body, the ceramic body has silicon nitride (Si.sub.3 N.sub.4), aluminum nitride (AlN) and alumina (Al.sub.2 O.sub.3), the weight ratio of aluminum nitride (AlN) and alumina (Al.sub.2 O.sub.3) to silicon nitride (Si.sub.3 N.sub.4) being in the range of 0.093 to 1.439; and at least one sintering additive is among the group consisting of yttrium oxide (Y.sub.2).sub.3), calcium oxide (CaO), lanthanum oxide (La.sub.2 O.sub.3), magnesia (MgO), cerium oxide (CeO.sub.2), scandium oxide (Sc.sub.2 O.sub.3), strontium oxide (SrO), barium oxide (BaO) and neodymium (Nd.sub.2 O.sub.3). The weight percentage of the sintering additive ranges from 0.3% to 15.0% of the total weight of the silicon nitride (Si.sub.3 N.sub.4), aluminum nitride (AlN) and alumina (Al.sub.2 O.sub.3).

Abstract: A composite ceramic material that is stable and shows a high strength in the temperature range of room temperature to 1600.degree. C. as well as has a toughness high-enough to be used as structural material and a process for producing it are provided. This composite ceramic material is composed of a matrix substantially made up of Si.sub.3 N.sub.4 and Si.sub.2 N.sub.2 O and a dispersion phase substantially made up of SiC where the matrix contains 0.05% by weight or less of metal element impurities such as Al, Ca and Fe. SiC grains or fibers are dispersed in the dense matrix made up of Si.sub.3 N.sub.4 and Si.sub.2 N.sub.2 O fine grains, which are substantially free from element impurities except Si, C and O. According to one aspect of this invention, this ceramic material is produced by Si.sub.3 N.sub.4 with SiO.sub.2 to form matrix powders that contain 0.

Abstract: A ceramic fiber product and method for manufacturing a ceramic fiber product for severe refractory environments. The method includes the steps of saturating a dry ceramic fiber material having an initial thickness with water or a nonbinding aqueous solution and squeezing the wetted ceramic fiber material to a latent compressed state having a thickness less than the initial dry thickness and removing liquid from the ceramic fiber material during the compressing step. The ceramic fiber is made of a material that springs back towards its initial dry thickness after drying. A monolithic ceramic fiber structure made from the ceramic fiber product is also described, as well as a kit for making a ceramic fiber structure and fasteners for attaching the product to a support form of the structure.

Abstract: A method of converting non-densified alpha-phase silicon nitride to beta-phase silicon nitride which includes heating a walled container enclosing a non-densified alpha-phase silicon nitride mass to an elevated temperature for a sufficient length of time so that the non-densified alpha-phase silicon nitride mass converts to a beta-phase silicon nitride mass. The walled container is formed of a silicon nitride-containing material which is stable at temperatures of at least 1700.degree. C. and is compatible with silicon nitride. Additionally, the walled container has an opening therein to allow placement of the non-densified alpha-phase silicon nitride mass therein.

Abstract: The present invention pertains to a refractory casting slip consisting of a refractory matrix material and a finely divided reactive component, as well as a hydraulic binder and various additives, which can be discharged as a free-flowing mass upon addition of water.

Abstract: The whiskers-reinforced ceramics of the present invention is prepared from alumina powder activated by dry milling, with which Ti-based whiskers are mixed, by molding and sintering said mixture.By the present invention the bending strength of the sintered body can be increased without impairing the effect of improving the fracture toughness which is imparted by the incorporation of Ti-based whiskers, since the particle size of alumina crystal in the sintered body can be controlled to 3 microns or less.

Abstract: A glass composition, containing barium oxide, which provides a source of leachable fluoride and which can be incorporated into a dental cement composition which, when cured, is radiopaque and translucent.