Abstract: The invention provides a silicon carbide sputtering target comprising non-stoichiometric silicon carbide, SiC.sub.x, where x is the molar ratio of carbon to silicon and x is greater than about 1.1 but less than about 1.45. The sputtering target of this invention is superior to sputtering targets prepared from presently available non-stoichiometric silicon carbide in that the DC magnetron sputtering rate using the new sputtering target is nearly an order of magnitude higher than the rate achievable with presently available targets. The invention also includes processes for making the new sputtering target and preparing superior silicon carbide films by sputtering the target.

Abstract: The invention includes a process for producing a reaction bonded silicon carbide composite reinforced with coated silicon carbide fibers which is suitable for high temperature applications. The process includes the steps of coating SiC fibers with AlN, BN or TiB.sub.2 ; treating the coated fibers with a mixture of SiC powder, water and a surfactant; preparing a slurry comprising SiC powder and water; infiltrating the coated fibers with the slurry to form a cast; drying the cast to form a green body; and reaction bonding the green body to form a dense SiC fiber reinforced reaction bonded matrix composite.The invention further includes a SiC fiber reinforced SiC composite comprising a reaction bonded SiC matrix, a SiC fiber reinforcement possessing thermal stability at high temperatures and an interface coating on the fibers having chemical and mechanical compatibility with the SiC matrix and with the SiC fibers.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %, in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.

Abstract: The invention includes a process for producing a reaction bonded silicon carbide composite reinforced with coated silicon carbide fibers which is suitable for high temperature applications. The process includes the steps of coating SiC fibers with AlN, BN or TiB.sub.2 ; treating the coated fibers with a mixture of SiC powder, water and a surfactant; preparing a slurry comprising SiC powder and water; infiltrating the coated fibers with the slurry to form a cast; drying the cast to form a green body; and reaction bonding the green body to form a dense SiC fiber reinforced reaction bonded matrix composite.The invention further includes a SiC fiber reinforced SiC composite comprising a reaction bonded SiC matrix, a SiC fiber reinforcement possessing thermal stability at high temperatures and an interface coating on the fibers having chemical and mechanical compatibility with the SiC matrix and with the SiC fibers.

Abstract: Disclosed is an aluminum nitride body having graded metallurgy and a method for making such a body. The aluminum nitride body has at least one via and includes a first layer in direct contact with the aluminum nitride body and a second layer in direct contact with, and that completely encapsulates, the first layer. The first layer includes 30 to 60 volume percent aluminum nitride and 40 to 70 volume percent tungsten and/or molybdenum while the second layer includes 90 to 100 volume percent of tungsten and/or molybdenum and 0 to 10 volume percent of aluminum nitride.

Abstract: Substrates are disclosed having an ultra-smooth surface finish thereon rendering them useful in making high density magnetic storage components, such as a computer hard disk or thin-film head which can read and/or write data on such disks. The substrates are comprised of a non-oxide ceramic base which is coated with a smoothing layer comprised of amorphous, non-stoichiometric silicon carbide corresponding to the formula SiC.sub.x, wherein x is the molar ratio of carbon to silicon and is greater than 1. Also disclosed are processes for making the substrates and components.

Abstract: The invention includes a process for producing a reaction bonded silicon carbide composite reinforced with coated silicon carbide fibers which is suitable for high temperature applications. The process includes the steps of coating SiC fibers with AlN, BN or TiB.sub.2 ; treating the coated fibers with a mixture of SiC powder, water and a surfactant; preparing a slurry comprising SiC powder and water; infiltrating the coated fibers with the slurry to form a cast; drying the cast to form a green body; and reaction bonding the green body to form a dense SiC fiber reinforced reaction bonded matrix composite.The invention further includes a SiC fiber reinforced SiC composite comprising a reaction bonded SiC matrix, a SiC fiber reinforcement possessing thermal stability at high temperatures and an interface coating on the fibers having chemical and mechanical compatibility with the SiC matrix and with the SiC fibers.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %. in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.

Abstract: Layered substrates are disclosed having an ultra-smooth surface finish thereon rendering them useful in making high density magnetic storage media. The layered substrates are comprised of a non-oxide ceramic core coated with a smoothing layer comprised of an amorphous metal, particularly certain amorphous metal alloys based on chromium, molybdenum, tungsten, and mixtures thereof. Also disclosed are magnetic storage media comprising the layered substrates, as well as processes for making the substrates and magnetic media.

Abstract: Substrates are disclosed having an ultra-smooth surface finish thereon rendering them useful in making high density magnetic storage components, such as a computer hard disk or thin-film head which can read and/or write data on such disks. The substrates are comprised of a non-oxide ceramic base which is coated with a smoothing layer comprised of amorphous, non-stoichiometric silicon carbide corresponding to the formula SiC.sub.x, wherein x is the molar ratio of carbon to silicon and is greater than 1. Also disclosed are processes for making the substrates and components.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 2 to 12 vol %. in which the pores are generally spherical and about 50 to 500 microns in diameter, are prepared from raw batches containing a polymer fugitive. Sintered bodies in the form of mechanical seal members exhibit lower power consumption at low PV and, in addition, lower wear rates at high PV in comparison to commercially available silicon carbide seal members.

Abstract: This invention provides a reaction-bonded silicon carbide article having superior abrasion resistance, oxidation resistance and uniformity in which the bond phase comprises appreciable amounts of both silicon oxynitride and alumina. Also provided are a raw batch and a process for producing the reaction-bonded article.

Abstract: A refractory tile adapted for protecting boiler tubes from the corrosive and erosive effects of a hot gas stream comprises an elongated ceramic body covering only that side of a boiler tube upon which the hot gas impinges. The tile is hung on the tube with a threaded stud anchored on the tube and a nut threaded on the stud, urging the tile against the tube.

Abstract: Disclosed is an aluminum nitride body having graded metallurgy and a method for making such a body. The aluminum nitride body has at least one via and includes a first layer in direct contact with the aluminum nitride body and a second layer in direct contact with, and that completely encapsulates, the first layer. The first layer includes 30 to 60 volume percent aluminum nitride and 40 to 70 volume percent tungsten and/or molybdenum while the second layer includes 90 to 100 volume percent of tungsten and/or molybdenum and 0 to 10 volume percent of aluminum nitride.

Abstract: An aluminum nitride ceramic having desired properties suitable for electronic packaging applications can be prepared from a novel aluminum nitride powder/sintering aid mixture. The sintering aid comprises a glassy component formed from alumina, calcia and boria, and a non-vitreous component comprising an element or compound of a metal of Group IIa, IIIa, or the lanthanides, preferably crystalline oxides, reactibis with the crystallized glass component and the alumina from the Al N grains. Alternatively, the sintering aid comprises a multi-component glass composition capable of forming the above components upon melting and thereafter crystallizing upon reaction.

Abstract: A predominantly .beta.'-sialon-bonded silicon carbide refractory article is produced by reaction-nitriding a green body containing a plurality of silicon carbide powders, none having an average particle size greater than about 200 micrometers, a metal oxide oxygen source, fine grained silicon, and a source of aluminum. The invention also includes a raw batch and a process for producing the refractory article.

Abstract: The invention provides a silicon carbide fiber carrying an aluminum nitride coating between about 1 and about 15 micrometers thick. The AlN coating serves as a debond layer which improves the fracture toughness of composite materials in which the coated fiber is a reinforcement phase.

Abstract: This invention provides a reaction-bonded silicon carbide article having superior abrasion resistance, oxidation resistance and uniformity in which the bond phase comprises appreciable amounts of both silicon oxynitride and alumina. Also provided are a raw batch and a process for producing the reaction-bonded article.

Abstract: Silicon carbide sintered bodies having controlled porosity in the range of about 3-25 vol % are prepared from raw batches containing a multimodal distribution of silicon carbide particles and comprised of at least a first set of particles having one average grain size and a second set of particles having another average grain size larger than the first set of particles. The resulting pores are 3-5 microns in the largest dimension, with an aspect ratio between about 1/1 and about 3/1 . The porous bodies, e.g., in the form of mechanical seal members, exhibit good tribological properties.

Abstract: This invention is directed to substantially strain-free, shaped, sintered ceramic fabric preform segments, to the production of the sintered preform segments from novel fixtured, shaped, green ceramic fabric preforms, and to sintered ceramic fiber-reinforced composite articles prepared from the sintered preforms and characterized in that the reinforcement phase is substantially free of mechanical strain, and the fiber in the fabric can exhibit a very small bending radius.