Abstract: An improved throw-away, or single use, adaptor particularly useful with depressed center grinding wheels is described. The adaptor comprises a hollow mandrel having an internal threaded portion for attaching the adaptor to the shaft of a grinding machine. The hollow mandrel has a saucer-shaped disc portion extending axially from the outer portion of the mandrel. The saucer-shaped disc portion has a concave surface and a convex surface. The concave portion is equipped with a plurality of internal rib members and has a flange around the periphery thereof to contact the side of a grinding wheel. The flange portion has a plurality of protrusions, or bosses, thereon adapted to be received in corresponding orifices in the grinding wheel. In operation, as the grinding wheel contacts a work piece, the torque, or stress, is directly imparted to the adaptor, as the adaptor is threadably attached to the shaft of the grinding wheel.

Abstract: A shrink resistant flexible ceramic fiber and its process of manufacture which comprises melting from about 40 to 65 weight percent of alumina with from about 35 to about 60 weight percent of silica, forming fibers from the melt, rapidly solidifying the fibers, heating the fibers to a sufficient temperature for a sufficient time to form microcrystals and cooling the fibers to below the crystallization temperature before macrocrystals can form.

Abstract: A process for strengthening carbide fibers by removing internal stresses caused by their formation. This process is accomplished by drawing the carbide fiber under tension through a furnace. The temperature of the furnace may range from about 2050.degree. to 2300.degree. C. while the fiber tensile stress may vary from about 200 to 3500 p.s.i. when using boron carbide fibers with diameters ranging from about 8 to 14 microns.

Abstract: A method of pressureless sintering silicon carbide mixtures to obtain a sintered, dense product when the silicon carbide starting materials do not include a densification aid, such as boron, beryllium or aluminum, is described. The starting materials are mixtures containing predominantly particulate silicon carbide and include usually less than about 10 and, preferably, less than about 6 percent by weight of carbon in the form of elemental carbon or in the form of a carbon source material. The mixtures may also contain minor amounts of other additives, such as lubricants, surfactants or agglutinants, to aid in forming a compact, or green body, from the mixtures, or minor amounts of other ceramic materials depending upon the nature of the desired final product. The mixtures are formed into compacts, or green bodies, by known techniques.

Abstract: An apparatus for fuel ignition comprising an electrical source for providing electrical current; an electrically operated fuel ignition means; a valve means which allows passage of fuel to the ignition means when the valve means is opened; a first valve control means which will open the valve upon application of an electrical current and a second valve control means which will retain the valve means in an open position but will not initially open the valve upon application of an electrical current; an activating switch electrically connected between the electrical source and the rest of the apparatus so that the apparatus will not operate unless the activating switch is closed; a time delay switch connected between the activating switch and the rest of the apparatus and connected to an ignition sensing switch means so that the time delay switch stops the flow of electrical current to the rest of the apparatus if the ignition sensing switch means does not sense ignition within the time delay; and an ignition s

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 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: Infusible cured phenolic resin fibers of the present invention have a birefringence of at least 2.times.10.sup.-3 with the x-ray diffraction pattern of the fibers showing an amorphous halo. The tenacity of infusible cured phenolic resin fibers is significantly increased by subjecting the fibers to sufficient longitudinal tension as to cause at least about 30% elongation of the fibers. The Young's modulus of elasticity of the fibers is also significantly increased thereby. Preferably the resulting stretched infusible cured phenolic resin fibers have a tenacity of at least about 4 g./den.

Abstract: Ceramic compositions that may be injection molded and subsequently sintered are described. The compositions include minor amounts of organo-titanates which materially reduce the viscosity of the compositions. The reduction in viscosity is particularly effective in compositions containing high loadings of silicon carbide as the ceramic material. The organo-titanates found useful are represented by the formula:(R.sub.1 --O).sub.m --Ti--(O--X.sub.z --R.sub.2).sub.nwherein:(a) m is an integer from 1 to 8 andn is an integer from 0 to 4,(b) m+n=4,(c) z is an integer from 0 to 1,(d) R.sub.1 is aliphatic containing 1 and 4 carbon atoms,(e) X is independently selected from the group of phosphite, phosphate, and pyrophosphate.(f) R.sub.2 is aliphatic containing from 8 to 25 carbon atoms.

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: The invention comprises the process for making an inorganic refractory insulation article by forming a fiber mat from a fiber slurry, impregnating the mat with a conditioned colloidal silica composition comprising colloidal silica, acid, aluminum chlorhydrate and water and drying the mat to form the article. The invention further comprises an inorganic refractory insulation article comprising randomly oriented refractory fibers retained by dried colloidal silica uniformly distributed throughout the article and from about 0.001 to about 1.5 weight percent of aluminum chlorhydrate which article is manufactured in accordance with the process.

Abstract: A method of removing nitrogen oxides (NO.sub.x) from exhaust gas mixtures is described. The removal of NO.sub.x from exhaust gas mixtures is accomplished by exposing the exhaust gas mixture, in a manner that does not substantially impede the gas flow, to a ceramic material containing from about 75% to about 95% by weight silicon carbide and from about 0.3% to about 10.0% silica. A reduction of at least 85% of NO.sub.x from the mixture is to be expected and reductions up to 95 to 100% are attainable. Ceramic mixtures containing silicon nitride in amounts between about 10% and about 30% are found to reduce the amount of NO.sub.x in exhaust gases at temperatures as low as 200.degree. C.

Abstract: Pressureless sintered silicon carbide ceramic bodies, having an equiaxed microstructure and an alpha crystalline habit can be produced 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 2250.degree. C., depending on the sintering atmosphere, under conditions such that a coating of carbon source is maintained on the finely divided silicon carbide, and sufficient boron is maintained within the shaped body during firing. Boron can be maintained within the shaped body by various techniques, such as the use of a "seasoned boat" or graphite container for the body being sintered, which has been saturated with boron by exposure to boron at or about the temperature of sintering.

Abstract: The present invention relates to fiber reinforced carbon and graphite articles that are characterized by a matrix of fibrous carbon material bonded together by a deposited pyrolytic material and having the residue of a carbonized filler material dispersed within the article in contact with the pyrolytic material.Fiber reinforced carbon and graphite articles are produced by(1) Forming reinforcing fibers into a shape without any binder material,(2) Infiltrating the fibers with a pyrolytic material in a manner to deposit pyrolytic material on the fibers and bond together the fibers, to form a bonded body,(3) Subsequently impregnating the bonded body with a carbonizable filler material, and,(4) Curing and carbonizing the filler material.The articles are substantially free of internal cracks and voids and are of high strength even at relatively low densities. As such, the articles are particularly useful in the aerospace industry where strong, lightweight materials are required.

Abstract: A refractory moldable composition which, upon drying, sets up to refractory shapes which are strongly adherent to the molding surfaces and are essentially crack-free, contains about 45 to about 65% of a liquid vehicle, such as water; about 21 to about 26% ceramic fiber; about 7 to about 30% finely divided silica; and sufficient adhesion enhancing agent to impart from about 18 to about 50 grams per square centimeter adherence to steel. The molded composition adheres excellently to molding surfaces and dries to give an essentially crack-free refractory shape, useful as thermal insulation at temperatures up to 1300.degree. C. The composition may optionally include hollow plastic or ceramic spheres.

Abstract: A sinterable silicon carbide mixture is described which is prepared by mixing finely-divided silicon carbide containing between about 0.5 and about 5.0 percent by weight of excess carbon with a finely-divided beryllium-containing additive wherein the amount of beryllium in the mixture is equal to between about 0.03 and about 1.5 percent by weight of the powder. A dense silicon carbide ceramic product is prepared from the powder mixture by pressureless sintering wherein the article is initially shaped and subsequently sintered in a beryllium-containing atmosphere at a temperature from about 1950.degree. to about 2300.degree. C.

Abstract: Gas is injected into molten metal, such as aluminum, to purify the molten metal either of dissolved gases (degassing), or of dissolved solids such as magnesium ( "demagging"). The apparatus for accomplishing this injection contains two metallic bath chambers, the molten metal being transferred from one chamber to the other through a conduit. A gas injection conduit is connected to the metal transfer conduit at a location submerged within the first metallic bath chamber from which metal is transferred to the second chamber, and the gas to be injected is introduced through this gas injection conduit into a location submerged within the first metallic bath chamber.

Abstract: Corrosive chemicals are contained in metallic vessels, the inside portion of which is coated with a homogeneous, porous polymer containing inorganic filler. The particle size, shape and distribution provides a controlled porosity which allows entrapped permeants from the corrosive chemical to escape, yet does not significantly affect the utility of the protective coating as a chemical corrosion barrier protecting the metallic vessel.

Abstract: A process for the manufacture of an aluminum oxide or zirconium oxide fiber comprising fiberizing a liquid containing lactic acid and an oxidizable compound selected from basic aluminum chloride, zirconium acetate and zirconium oxychloride and the resulting fibers. The liquid optionally also contains colloidal silica.

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.