Abstract: The invention relates to ceramic composite articles formed by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix produced as a metal-oxidant reaction product. The bed or preform includes a dross material.

Abstract: Production of composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix produced as a metal-oxidant reaction product, wherein the bed or preform is comprised of dross.

Abstract: A gas distributing device is provided for a Metal Organic Chemical Vapor Deposition (MOCVD) reactor. The gas distributing device comprises a packed bed of discrete particles located in the inlet of the reactor to provide a vortex-free flow of reactant gas mixture towards the susceptor within the reactor chamber. The packed bed of discrete particles is of sufficient depth to provide a series of tortuous interconnecting channels around and between the particles and through the bed. A porous support is provided for the packed bed in the inlet of the reactor chamber. The porous support device adjacent the reactor chamber permits a reactant gas mixture after having passed through the packed bed to enter the reactor chamber.

Abstract: The invention relates to ceramic composite articles formed by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix a metal-oxidant reaction product. The bed or preform includes a dross material.

Abstract: A method of producing a composite comprising a self-supporting polycrystalline material obtained by oxidation reaction of a molten parent metal with a vapor-phase oxidant comprising infiltrating a filler exhibiting inter-particle pore volume with a parent metal under conditions which control the respective rates of said metal infiltration and said oxidation reaction.

Abstract: The invention relates to method for producing composite ceramic articles by infiltration of a particulate, permeable bed or permeable preform with a polycrystalline matrix a metal-oxidant reaction product, and the bed or preform includes a dross material.

Abstract: A method of making fine particulate aluminum nitride, including the steps of reacting gaseous aluminum trichloride with aluminum-containing metallic material at elevated temperature to convert some of the trichloride to monochloride gas; introducing a gaseous nitrogen source to the monochloride-containing gas for reacting nitrogen with the monochloride to form fine particulate aluminum nitride; conducting a flow of gas comprising aluminum trichloride having the particulate nitride entrained therein to a cooling locality; there condensing the trichoride and accumulating the condensed trichloride and particulate nitride; and periodically reevaporating and removing the trichloride from the cooling locality for separating out and recovering the accumulated nitride.