Abstract: A fused abrasive grain, useful for inclusion in coated abrasives and bonded abrasives, consists essentially of alumina; titanium oxide containing from about 0.42 to about 0.84% titaniun, by weight of the abrasive grain, present as a reduced titanium oxide having an average oxidation state lower than in Ti.sub.2 O.sub.3 ; from about 0.05 to about 0.3% by weight carbon; from about 0.02 to about 0.1% by weight Na.sub.2 O; and from 0 to about 0.1% by weight total of calcium and silicon oxides. The grain before roasting has a gain on ignition of from about 0.4 to about 0.7% by weight, and is produced in an electric furnace by fusing high-purity titania, alumina containing Na.sub.2 O as the only significant oxide impurity, and carbon, followed by crushing and roasting the fused grain.

Abstract: There is disclosed a device for securing refractory and/or insulating material against a furnace wall. The device comprises a metal pin or stud which is attached to the wall at one end and is provided with a plurality of notched portions adjacent the other end. The stud cooperates with a hollow, preferably ceramic anchor, which is provided with a rectangular slot that fits over the notched portion of the stud and may be secured thereon by rotating an anchor through 90 degrees to effect a locking arrangement. The anchors may be interfitted in order to provide a support for electrical heating elements. The significant feature is that the size of the anchor is such as to allow another anchor to interlock and make a collar which can support electrical heating elements. As the anchor is preferably a ceramic support it is electrically insulating, and prevents the electrical heating elements from contacting the studs.

Abstract: A thermal insulation assembly for use in conjunction with a similar assembly to encircle an elongated body, said assembly comprising a series of abutting similar U shaped elements which have similar radial and axial orientation, said series and orientation being retained by a plurality of elongated rods passing through said elements.

Abstract: Ceramic compositions that may be injection molded and subsequently sintered are described. A particulate ceramic material, such as silicon carbide, is coated with a mixture of thermoplastic resin and oils or waxes, and utilized as a feed material in an injection molding process. The molded product may subsequently be sintered at 2000.degree. C. to 2200.degree. C. to produce a hard, dense article.

Abstract: A dense thermal shock resistant silicon carbide ceramic body and its method of manufacture which comprises heat sintering a shaped body comprising particulate silicon carbide and an additive selected from boron nitride, boron phosphide, aluminum diboride and mixtures thereof.

Abstract: A method for making a dense thermal shock resistant silicon carbide ceramic body by hot pressing a blend of silicon carbide and from about 0.2 to about 2 weight percent of aluminum diboride and the resulting body.

Abstract: Spherical bonded abrasives, having a hollow core and comprising abrasive grain fused on the periphery of a thermoplastic carrier, are made by (1) heating thermoplastic support media, enveloped by abrasive grain, within the thermoplastic range for sufficient time to fuse the abrasive grain onto the surface and (2) cooling. Such spheres are useful in coated abrasive products, providing greater useful life for coated abrasive belts so made.

Abstract: A boron nitride bonded boron nitride fiber article and the method for its manufacture which comprises forming a shaped article with a composition comprising boron oxide fibers and boric acid, heating the composition in an anhydrous gas to a temperature above the melting point of the boric acid and nitriding the resulting article in ammonia gas.

Abstract: Pressureless sintering of silicon carbide to produce ceramic bodies having 75% and greater theoretical densities, can be accomplished by firing shaped bodies, containing finely divided silicon carbide, boron source such as boron carbide, carbon source such as phenolic resin and a temporary binder, at a sintering temperature of from about 1900.degree. C to about 2500.degree. C.

Abstract: A powder containing substantial amounts of alpha phase silicon carbide suitable for use in subsequent sintering operations to obtain a high-density, high-strength ceramic product is described. The powder may consist substantially entirely of alpha silicon carbide or may consist of mixtures of alpha and beta phase silicon carbide. The silicon carbide powder of the present invention has an average particle size of from about 0.10 to about 2.50 microns and may contain maximum amounts of the following materials by weight based upon 100 parts of powder.______________________________________ SiO.sub.2 2.00 Free Silicon 0.25 Iron 0.50 Alkali and Alkaline Earth Metals 0.50 Total Metal Oxides 3.75 ______________________________________Sinterable powders and methods of producing sintered products from the powders are also described.

Abstract: A composition comprising negatively doped hot pressed particulate silicon carbide, the process for making the composition, an electrical hot surface fuel ignitor manufactured from the composition, a silicon brazed electrical connection for the ignitor and an ignitor circuit containing a dropping resistance.

Abstract: A ceramic fiber module, suitable for lining furnaces, comprises a weldable (metallic or perforate refractory) backing and a number of ceramic fiber mats cemented to the backing by the edge of the mat, so as to leave a portion of the backing accessible between mats or on their perimeter, for welding. The weldable backing is welded to a metallic substrate, preferably by use of spherical attachments, to provide thermal protection to the metallic substrate.

Abstract: A reinforced carbon article which comprises a carbon fiber shape bonded by a carbon binder and having incorporated within said article a friction modifier, e.g., the in situ reaction product of carbon and a boron containing additive which comprises a material selected from the group consisting of boron, boron nitride, boron silicide and refractory metal borides; and a process of making such an article which comprises forming a carbon fiber shape, dispersing a boron containing additive within at least a portion of said carbon fiber shape, impregnating the carbon fiber shape with a carbonizable binder, and heating the shape to carbonize the binder and to form in situ the reaction product of carbon and the boron containing additive.

Abstract: A fused abrasive grain, useful for inclusion in coated abrasives and bonded abrasives, consists essentially of alumina; titanium oxide containing from about 0.42 to about 0.84% titanium, by weight of the abrasive grain, present as a reduced titanium oxide having an average oxidation state lower than in Ti.sub.2 O.sub.3 ; from about 0.05 to about 0.3% by weight carbon; from about 0.02 to about 0.1% by weight Na.sub.2 O; and from 0 to about 0.1% by weight total of calcium and silicon oxides. The grain before roasting has a gain on ignition of from about 0.4 to about 0.7% by weight, and is produced in an electric furnace by fusing high-purity titania, alumina containing Na.sub.2 O as the only significant oxide impurity, and carbon, followed by crushing and roasting the fused grain.

Abstract: A resin bonded abrasive article and the process for its manufacture which comprises blending a cuprous oxide with an abrasive and bonding resin, shaping the resulting blend and curing the resin to form a resin bonded abrasive article. The invention further comprises the same process wherein an organosilane is incorporated into the blend.

Abstract: Phenolic resins employed for melt spinning fibers are modified by the incorporation therein of from about 5% to about 30% of an aliphatic nylon, whereby the melt spinning characteristics of the phenolic resins are improved and the tenacity of the melt spun fibers is increased.

Abstract: Disclosure is made of a high-density, high-strength silicon carbide ceramic material that is produced using a silicon carbide powder containing boron or boron-containing compound as a densification additive by the utilization of boron in the sintering atmosphere.

Abstract: A cured novoloid fiber and the process for its manufacture which comprises blending a crosslinking agent with a novolac resin at a temperature below about 40.degree. C, rapidly melting the blend, fiberizing the melted blend before it can cure and curing the resulting fibers by exposing them to an acidic gas.

Abstract: Boron nitride-boron nitride composite bodies may be produced by combining pure boron nitride fibers with partially nitrided fibers consisting essentially of B, N, O, and H, and hot pressing the composite at elevated temperatures and pressure. The partially nitrided material serves as a source of matrix material for the boron nitride fibers, and when fiber orientation is properly controlled, bodies of extremely high strength may be obtained. Densities in excess of 1.5 g./cc. may be obtained, in a one-step process which overcomes difficulties inherent in multiple-step nitriding and re-nitriding processes.

Abstract: A thermal insulation assembly for use in conjunction with a similar assembly to encircle an elongated body, said assembly comprising a series of abutting similar U shaped elements which have similar radial and axial orientation, said series and orientation being retained by a plurality of elongated rods passing through said elements.