Abstract: A molten metal filter is disclosed having a carbon or carbon-thermite coating that reduces thermal shock to the filter, and protects the filter from corrosion from the metal or components and impurities in the metal, and prevents metal from freezing in the filter. A molten metal assembly suitable for casting molten metal is disclosed which comprises a filter for molten metal and means for molten metal flow passage leading through the filter. The means have surfaces defining a molten metal path. The filter has a coating of carbon or carbon in intimate contact with a thermite material on the surface of the filter. A process is disclosed for filtering molten metal which comprises passing molten metal through the above described coated filter.

Abstract: Novel method and apparatus is disclosed for forming an integral skin on an extruded honeycomb structure, wherein the skin material is collected in a peripheral area of a die body, is passed through an adjustable flow control gap, and then through a predetermined gap thickness of a skin forming slot so as to then knit with the honeycomb structure extruded by the die prior to being extruded from the die. A plurality of flow control plates having different internal peripheral diameters are provided so as to provide different flow control gaps, as desired. In addition, a plurality of shims having different thicknesses are provided so as to position the mask a given distance away from the die, and thereby control the skin thickness gap. The die may be formed by merely relieving a peripheral portion of a typically automotive catalytic converter extrusion die and providing a trim ring about the relieved portion so as to inhibit the flow of batch material from partially open feed holes.

Abstract: An extrusion die for forming honeycomb type structures, such as filters. In a typical prior art extrusion die, the feed holes are circular in cross section throughout their length and feed into respective intersecting discharge slot portions. There is an abrupt change in cross section area and shape, from circular to cross shaped, at the entrance to the discharge slots. This construction results in flow inhibiting land portions at the entrance to the discharge slot portions. Such a construction causes bending forces or moments on these flow obstructing entrance portions of the discharge slots and also subjects them to increased abrasive wear whenever the material being extruded contains ceramic or other hard particles. By this invention, the feed holes are uniformly tapered from an annular or polygonal transverse cross section at their input ends to a (conventional) cross shape at their outlet ends where by feed the discharge slots.

Abstract: Ceramic honeycomb structures having channels that are selectively sealed at alternate faces of the honeycomb are prepared by applying an end cap made up of green ceramic material to each face of a green ceramic honeycomb body, followed by exposing the openings of certain channels of the honeycombs through the cap at one face and exposing the remaining channels through the cap at the other face. Thereafter, the composite capped structure is fired. The honeycombs are useful in a variety of filtering, separating, or concentrating operations in which a work fluid or component thereof is intended to pass through the walls of the channels.

Abstract: A structure comprising a mixture of metals and metal alloys which are sintered into a hard porous body is presented. The structure can be useful for many different chemical and physical purposes, such as for catalysis, desorption and absorption, and selective leaching of the structure components into solutions.

Abstract: Laminated extruded thermal shock resistant composite articles formed from sinterable particulate or powdered materials such as ceramics are disclosed. The laminated extruded composite articles have multiple discrete layers of at least a first and second sintered material, where the first and second sintered materials are different and are selected from high strength sintered particulate or powdered materials and where the layers of each of said first and second sintered materials are substantially uniformly distributed throughout the article.

Abstract: A monolithic ceramic structure, useful as a support for catalytic material or as a fluid filter, has a high surface area phase which consists essentially of a porous metal oxide material, at least 50% by weight of which is alumina, titania, and/or zirconia, and phosphate dispersed substantially througout the porous metal oxide material. The presence of the phosphate stabilizes the porous metal oxide material against thermal degradation during sintering or exposure to elevated temperatures encountered in catalytic service and thereby aids in the retention of higher overall surface area in the monolithic structure.

Abstract: Ceramic honeycombs made of a ceramic material of a solid electrolyte nature having at least some of the honeycomb channels sealed at one of the faces are useful for the concentration or separation of oxygen from air or other oxygen-containing gaseous mixture. The oxygen-containing gas is introduced into a first set of channels at one face of the honeycomb, a first voltage is applied to the interior walls of those channels, and a second voltage applied to the interior walls of the second set of remaining channels, thereby creating an electrical potential across the ceramic material separating any adjacent channels of the two sets. The electrical potential drives oxygen ions through the channel walls releasing concentrated oxygen into the second set of channels for collection therefrom.

Abstract: Thermite coatings are applied to molten metal filters and the environs, to produce longer lived filters that can be utilized in harsher environments. The coatings employ exothermic, redox, and combination reactions to produce the beneficial effects.

Abstract: A mask apparatus for charging flowable materials into selected cells of a honeycomb structure comprising a solid body having a number of openings extending therethrough which are spaced to coincide with the open ends of the selected cells exposed at the structure's end face, after the mask is positioned across the end face, the flowable material is charged through its openings. In one embodiment, a rigid plate having a number of bores therethrough is provided for charging a plastically formable plugging material into a honeycomb structure in the fabrication of solid particulate filter bodies and other selectively manifolded structures. In a preferred embodiment, a thin transparent polyester film is attached to an open surface of a honeycomb structure and openings melted therethrough.

Abstract: A cured sintered porous metal structure comprising aluminum and aluminum alloys is presented comprising an aluminum oxide durable surface integral to the structure. The surface layer is enhanced in aluminum while the underlying structure is thereby depleted in aluminum. The structure exhibits surface and interfacial durability.

Abstract: A bowl-shaped, concave reflector, adapted to be assembled with a lamp to provide light reflection, is disclosed. The reflector has a large, front opening through which light is projected, and which is bordered by a peripheral rim composed of four corner zones and four side zones alternating therewith. The width of the rim in the corner zones is greater than that in the intermediate side zones, and the wall of the reflector has four flattened zones adjacent the side zones of the rim, whereby the reflector has the exterior appearance of a four sided body.

Abstract: Sintering metal powder in inert and/or reducing atmosphere has been found to result in a hard porous metal structure without the use of sintering aids. The oxidation resistance of the structure can be enhanced by the firing process comprised of the following steps: oxidation, reduction, and then inert gas sintering.

Abstract: The present invention is directed to porous sintered aluminide structures of aluminum, nickel, titanium, and/or rare earth metal. A process is disclosed for forming and sintering aluminides. Other components are optionally added to the aluminide compositions to vary the physical properties of the resultant structure.

Abstract: A rigid mini-monolith structure formed by extrusion from a die. Such structures are useful as catalyst supports for treating exhaust gases from automobile. The structure is in the shape of a right circular cylinder with a plurality of internal cells extending along the substrate and an opening on both ends. In order to provide maximum crushing strength of the structure, as well as permitting uniform intercell wall thickness at the downstream face of the extrusion die which forms the structure, the majority of the cells are formed in the transverse cross section of a truncated (circular) sector and have the property that they each possess the same hydraulic diameter, although not all are of the same transverse cross sectional shape. The invention also is defined by a novel extrusion die formed by a plurality of concentric, collared tubes provided with longitudinally running slots in the tubes and notches on the collars, the tubes being radially spaced from each other.

Abstract: Novel calcium dialuminate/hexaluminate ceramic structures in the form of blends, laminates and composites, and processes for making these structures are disclosed. The ceramics of the invention exhibit relatively lower levels of thermal expansion, high strengths, and good thermal shock resistance over wide temperature ranges.

Abstract: The present invention is directed toward the improvement of the properties of cordierite sintered structures. The improvement consists essentially of heat treating the calcined kaolin component which when added to the batch of ray materials increases the thermal shock resistance and decreases the coefficient of thermal expansion.

Abstract: A metal casting mold formed of a ceramic material. The mold is reusable and is formed of a crystalline ceramic whose coefficient of thermal expansion (in the range 0.degree. to 1000.degree. C.) is between about 0 and 15.times.10.sup.-7 /.degree.C./ The mold interior surface includes at least one projection extending towards the mold cavity. The projection is provided with a release (draft) angle of about 6.degree., tapering away from the base of the projection. Upon pouring, the molten metal surrounds at least a portion of the projection. Upon cooling within the mold, shrinkage of the metal casting against the tapered sides of the projection forces the casting along the projection, toward the latter's tapered end and away from the mold interior surface and thus partially out of the mold cavity. A method of making the ceramic mold of this invention is also disclosed.

Abstract: An extrusion die assembly for making honeycomb structures of ceramics, glass, and other extrudable materials. The assembly is provided with an apertured, flow controlling forming plate placed against the input (upstream) surface of the extrusion die. The forming plate has a central opening through which the batch material to the input face of the die passes. A series of angularly spaced, flow controlling openings lies radially outwardly of the rim of this central opening. These forming plate openings are axially aligned with a shim reservoir downstream of the discharge slots of the die. This arrangement permits both the flow volume and rate of the batch material being extruded to the skin forming portions of the die assembly to be at least partially independently controlled relative to the flow volume to the main, radially central portion of the extrudate. By this construction, the formation of air checks in the shim reservoir and the formation of rippled skin on the extrudate is inhibited.

Abstract: This invention relates to the high temperature stabilization of aluminum titanate and aluminum titanate-mullite compositions by the addition of iron oxide. It has been found that iron oxide concentrations greater than 5 weight percent and as high as approxkmately 25 weight percent have a stabilization effect at high temperatures on aluminum titanates. The resultant ceramic body is further enhanced by the addition of from 0.1 to 5 weight percent rare earth oxide.