Abstract: Sprayable fireproofing compositions for structural members such as steel columns are provided. The compositions comprise a cementitious binder such as Portland cement, and a hard aggregate containing water of hydration. Such hard aggregates contribute not only to the strength of the fireproofing composition, but also contribute thermally. The product is produced by dry blending a mixture of the cementitious binder and hard aggregate, as well as other optional additives. Upon the addition of water, sprayable slurries are formed which can be pumped to the point of application. An accelerator is added in close proximity to the point of injection. Other additives may also be included, such as starch, adhesives and cement strength enhancers. The slurries adhere to the structural member in the slurried state and after setting to provide excellent fire and heat protection.

Abstract: A wear-resistant alumina material is disclosed, as is its preparation by liquid phase sintering a mixture of about 70 to 95 percent by weight of crystalline Al.sub.2 O.sub.3 particles and about 30 to 5 percent by weight of glass phase-forming components in a nitrogenizing atmosphere from which oxygen is substantially excluded. Generally, the resulting material has a 5 Kg Vickers hardness which is at least about 5 percent greater than the hardness of a corresponding alumina material sintered in air.

Abstract: A process for improving the oxidation resistance of carbon or graphite fiber reinforced carbon composites includes infiltrating the structure with a ceramic precursor-laden supercritical fluid, depositing the ceramic precursor within the internal porosity and pyrolyzing the precursor material in situ.

Abstract: An improved welding cup is made from graphite or ceramic fiber composites, coated with silicon nitride, sialon, boron nitride, or silicon carbide. The cup shows superior resistance to erosion, slagging, and thermal fracture.

Abstract: A ceramic composite valve for an internal combustion engine or the like is disclosed. The valve includes (a) an elongated valve stem shaped for insertion in the valve guide of an engine and comprising a ceramic sleeving which is packed with an axially aligned unidirectional cluster of ceramic reinforcing fibers; and (b) a ceramic bell shaped for mating with the valve seat of an engine and containing discontinuous ceramic fibers; one end of said sleeving being molded into the bell to form a valve-shaped structure; and said valve shaped structure being impregnated and rigidized with a matrix of carbon, other ceramic material, or both carbon and other ceramic material, and coated with a hard ceramic coating which is resistant to oxidation and wear. Also disclosed are various preform valves, and a method of making ceramic valves and preform valves.

Abstract: A ceramic fiber-reinforced ceramic heat exchanger includes a tube sheet and one or more coiled, oval cross-section U-tubes formed integrally with the tube sheet, wherein both the tube and tube sheet are composed of a ceramic fiber-reinforced ceramic composition, particularly suited for waste heat recovery in harsh flue gas environments.

Abstract: Supercritical fluids may be used to carry ceramic precursor materials into the pores of a ceramic host. Reducing the solubility of the ceramic precursor in the supercritical fluid will cause deposition of the ceramic precursor in the pores or void spaces of the ceramic host and accomplish densification of the ceramic host material.