Abstract: An aluminum oxide-based sintered object having excellent abrasion resistance includes .alpha.-aluminum oxide, a silicon compound and a tungsten compound, wherein the silicon compound and the tungsten compound are present in amounts based on starting amounts of SiC and W metal of from 5 to 40 mole % and from 0.5 to 25 mole %, respectively, based on the sintered object overall, with a W/SiC molar ratio of 4 or less, and in which particles of at least one of tungsten carbide and tungsten silicide having an average particle diameter of 0.5 .mu.m or less are dispersed as a crystalline phase.

Abstract: A pavement marking that has yellow-tinted, retroreflective beads partially embedded in a bead-carrier medium. The bead-carrier medium contains 0.5 to 15 volume percent of a light-scattering agent that scatters white light. The pavement marking is able to retroreflect a distinct yellow color at nighttime without using yellow pigments that contain the potentially-toxic metals, cadmium, chromium, and lead.

Abstract: The invention relates to a pigment containing carbon black having improved abrasion resistance comprising a platelet-shaped substrate coated with a metal oxide layer containing carbon black, wherein the carbon black is fixed on the substrate by means of an anionic or cationic and a nonionic surfactant and an organosilane compound.

Abstract: A method for producing dense aluminum nitride articles having enhanced thermal conductivity is disclosed. The method comprises the steps of forming a powder compact comprising AlN alone or in combination with other ceramic compounds, adding a densification aid, subsequently exposing the compact to an environment which serves to reduce the oxygen content of the compact, and then densifying the compact by sintering or hot-pressing to provide a dense article. The densified AlN article is found to have a high thermal conductivity.

Abstract: The present invention provides a simple inexpensive means to decrease the abrasivity of abrasive pigments such as calcined kaolin and titania. In accordance with this invention, a trace of a nonionic and/or anionic surfactant is incorporated with abrasion pigment prior to or during the preparation of an aqueous pigment slurry or to dry pigment.

Abstract: A carbon powder is disclosed with 40 to 75% by weight QI or more than 90% by weight TI, an optical anisotropy of less than 50% by volume, a start of softening between 200.degree. and 300.degree. C., and an oxygen content of more than 2% by weight, and which can be used for without binding agent the production of shaped carbon bodies. The carbon powder is produced by means of distillation from bituminous product at a maximum of 5 mbars and a final temperature of at least 400.degree. C., grinding of the distillation residue to a particle size of less than 30 .mu.m, and oxidation of the powder into the particle core.

Abstract: A proteinaceous gelatin binder is used to make aqueous green ceramic compositions suitable for forming green ceramic tape by tape casting. Any known ceramic may be used. The tapes may be fired individual or as a laminate to produce sintered ceramic articles.

Abstract: Aggregate pigment products made of low-refractive-index raw materials, in which pigmentary, subpigmentary and nonpigmentary components are cemented intrinsically with the aid of in-situ synthesized complex microgels.

Abstract: A new doped zirconium mixed silicate pigment has been found, having a particle size D.sub.50 of 3 .mu.m or less and a molar ratio of zirconium dioxide/silicon dioxide that deviates from the stoichiometric ratio and is in the range of 1/1.5-1/36. This new pigment is doped with 1-25% by weight of a color-providing metal oxide an exhibits great color strength as well as good thermostability. The new pigment, which has a very high particle fineness, can be used for ceramic applications and for coloring glass, but is also particularly suitable for applications outside the ceramic field, in particular as a colorant in plastics, rubber, paint, printing ink and cosmetic products. Further, a similar new doped zirconium silicate pigment has been found, which, however, has a D.sub.50 particle size that is greater than 3 .mu.m, the molar ratio of zirconium dioxide/silicon dioxide being in the range of 1/4.9-1/36. The last-mentioned pigment is very suitable to be incorporated into glass.

Abstract: A method of producing a self-supporting ceramic composite body having therein at least one cavity which inversely replicates the geometry of a positive mold of parent metal. The method includes embedding the mold of parent metal within a conformable bed of filler to provide therein a cavity shaped and filled by the mold. The assembly is heated to melt the parent metal mold, e.g., an aluminum parent metal mold, and contacted with an oxidant to oxidize the molten parent metal to form a polycrystalline material which grows through the surrounding bed of filler, the molten metal being drawn through the growing polycrystalline material to be oxidized at the interface between the oxidant and previously formed oxidation reaction product whereby the cavity formerly filled by the mold of parent metal is eventually evacuated of the metal. There remains behind a cavity whose shape inversely replicates the original shape of the mold.

Abstract: This invention is directed to the fabrication of magnetic memory storage devices which consist essentially of a head pad and a rigid information disc, that disc consisting essentially of a rigid substrate having a layer of magnetic media joined to the surface of said substrate through an underlayer. The invention is particularly drawn to the substrate for the information disc which is composed of a glass-based material containing 0.05-2% by weight total of cobalt oxide and/or iron oxide and/or nickel oxide. The most preferred glass-based material comprises a glass-ceramic wherein canasite constitutes the predominant crystal phase.

Abstract: The invention relates to carbon-containing plate-like pigments, obtainable by pyrolysis of carbon-containing compounds in the presence of either plate-like metal oxides or metal oxide mixtures or plate-like substrates coated with titanium dioxide and at least one further metal oxide under conditions in which the metal of the metal oxide is reduced.

Abstract: Boron-containing iron-oxide pigments as disclosed which are prepared by a nitrobenzene reduction process. The boron is present in the pigments in a homogeneously doped form in amounts of 0.02 to 0.13% by weight, based on iron oxide. Preparation of the pigments is also described.

Abstract: A temperature-resistant black pigment which is a mixed oxide of manganese and iron with the structure of hematite and having a manganese content of 3 to 35% by weight, and with absolute color values in colorimetric testing in paint systems, expressed in CIELAB units, in the lightened form (Blend of 10 parts titaniumdioxide and 1 part of black pigment) of 60 to 70 for L*, -0.5 to 1.9 for a* and -4 to -6.5 for b* useful for coloring autoclave-cured building materials and for pigmenting heat-resistant paint systems is obtained by preparing a precursor material of manganese and iron oxides or hydroxides, which contains the phase with the structure of spinel and calcining that precursor material in an oxidizing atmosphere at 500.degree. to 1,000.degree. C.

Abstract: A method for producing a self-supporting ceramic composite body which comprises preparing a polycrystalline material as the oxidation reaction product of a parent metal with a vapor-phase oxidant, comminuting the resulting material to a particulate, forming a permeable mass of said particulate as filler, and infiltrating said particulate with an oxidation reaction product of a parent metal with a vapor-phase oxidant, thereby forming said ceramic composite body.

Abstract: A process for producing beryllium oxide (BeO) from beryllium hydroxide (Be(OH).sub.2) in a single reactive step. Beryllium hydroxide powder is mixed with a calcination additive containing Mg and/or Ca and calcined at 1000.degree.-1300.degree. C. The resultant oxide pow-der is characterized by low fluorine content (<100 ppm), low surface area (<1.5 m.sup.2 /g) and a controlled particle size of 2 .mu.m to 25 .mu.m.

Abstract: A refractory adhesive and filler paste composition is described which can be extruded, trowelled or parged onto a refractory surface. The composition can be used to adhesively secure shaped refractory articles together or used as a filler. The composition contains refractory grain particles having critical size limitations and a non-aqueous binder system which includes an unsaturated drying oil such as tung or linseed oil and an organic solvent such as naphtha. The composition may be premixed and packaged in a caulking gun cartridge and applied by extrusion.

Abstract: A process is disclosed for producing sintering active silicon nitride powders with low oxygen content by wet grinding a silicon nitride starting material, leaching the ground suspension with fluorine-free mineral acid, and separating off the purified silicon nitride powder.

Abstract: New electromagnetic interference (EMI) shielding pigments based on silver coated carrier pigments are disclosed which have a wider activity spectrum and are more economically available than previously known shielding pigments. The carrier pigments used are platelet shaped, ferro- or ferrimagnetic, Fe-containing, naturally occurring or synthetically produced laminar minerals. The Ag coating amounts to 5 to 25% by weight, based on the carrier pigment. Shielding pigments, which may be prepared by conventional chemical deposition of Ag or by sputtering, may be used for the production of EMI protective coatings and EMI protective films.

Abstract: In the process for cooling the reaction products of the vapor phase oxidation of titanium tetrachloride to titanium dioxide comprising: (a) passing said reaction products through an externally cooled conduit, and (b) admixing with the reaction products particulate scrubbing material which removes solid deposits adhered to the interior walls of the conduit, the improvement characterized by:using as the scrubbing material about 0.5-15 percent by weight, based on the weight of titanium dioxide, of compacted particles of titanium dioxide pigment, said compacted particles of titanium dioxide pigment being produced by subjecting titanium dioxide pigment to sufficient pressure to form same.