Abstract: Compound preforms are provided having a first region, including a porous ceramic and a second region including a porous or solid ceramic in which the two regions differ in composition. The compound preform is infiltrated with a liquid metal which is then solidified to form a metal matrix composite.

Abstract: Compound preforms are provided having a first region, including a porous ceramic and a second region including a porous or solid ceramic in which the two regions differ in composition. The compound preform is infiltrated with a liquid metal which is then solidified to form a metal matrix composite.

Abstract: Compound preforms are provided having a first region, including a porous ceramic and a second region including a porous or solid ceramic in which the two regions differ in composition. The compound preform is infiltrated with a liquid metal which is then solidified to form a metal matrix composite.

Abstract: A cutting tool of the type having a tool support with a cutting tip of CVD diamond film brazed to it has the diamond material so oriented that the general direction of grain boundaries is not normal to the general plane of the rake face.

Abstract: Strong and durable silicon nitride filtration membranes with effective separating layers having effective pore diameters less than about 1 micron are produced by depositing a source of silicon onto a porous microfilter support, removing any liquid used in the depositing, and subjecting the silicon source to nitridation conditions. Suitable sources of silicon include silicon per se and silica. When silica is used, a suitable reducing agent is deposited therewith to reduce the silica to silicon in situ.

Abstract: Strong and durable alpha alumina ultrafiltration membranes with effective separating layers having effective pore diameters less than about 50 nm, and particularly at almost any point within the range of about 10 to about 50 nm, can be produced by seeding boehmite sols with appropriate seeds, such as very fine alpha alumina with a specific surface area of more than 100 sq. m. per g, gelling a thin layer of the sol by contact with a microfilter support, drying the gel, followed by controlled heating of the coated support both to convert the boehmite to alpha alumina and to simultaneously control the effective pore diameter of the resultant membrane.

Abstract: This invention provides thin, flat, water-impervious polycrystalline ceramic bodies composed of at least 99.5% by weight alumina, predominantly in the alpha crystal form. These bodies have a density of at least 3.9 Mg/m.sup.3, an average surface roughness of 44 nm or less, typically 40 nm or less. The properties of the finished ceramic bodies make them ideal substrates for highly reliable electronic components, especially for high temperature environments. Processes for obtaining such bodies by direct firing of slip cast tapes are also described.

Abstract: Forming plates for the extrusion of foam from a slot die are provided which are adjustable in relationship to a generally adjacent die face. A movable plate portion is disposed adjacent the die face. The movable portion has a semi-cylindrical groove disposed therein. A pivoting forming plate having half-round edges has one edge disposed within the movable plate. The opposed half-round edge of the pivoting plate rests in a semi-cylindrical groove within a fixed forming plate. A similar opposed plate arrangement is employed on the opposite side of the die slot.