Abstract: A body having a large number of protrusions is aligned with a honeycomb surface having a greater number of openings, selected openings being engaged by the protrusions when the body is aligned, by positioning the body against the honeycomb surface and vibrating it until the protrusions engage. The method is of particular use in aligning flexible masks to end faces of honeycomb structures in the fabrication of solid particulate filter bodies. Particular mask and honeycomb structure geometries are suggested for automation of the process.

Abstract: Substantially spherical mono-sized particles of zirconia can be prepared by the forced hydrolysis of an aqueous solution of zirconyl chloride. A zirconyl chloride solution having a molarity up to about 0.4 is heated for at least 72 hours at a temperature of at least 95.degree. C. to generate suspended particles of hydrated zirconium oxide, which are recovered and calcined to provide the mono-sized zirconia powders. In preferred embodiments, mono-sized powders of a mixture of zirconia with one or more of its stabilizing metal oxides is prepared by precipitating the metal in the form of its hydroxide onto pre-formed zirconium-containing particles.

Abstract: The invention is a flexible mask for use in charging a flowable material into selected cells of a honeycomb structure and is of particular utility in charging a sealing material into the ends of selected cells of such a structure during fabrication of solid particulate filter bodies and other selectively plugged honeycomb structures. The mask has a central body with a set of openings extending therethrough which allow passage of the flowable material through to the selected cells and a second set of protrusions extending from one of the surfaces of the mask which are used to align the mask to the end face of the structure and which extend into and sealably cover the cells which are not to receive the flowable material. The mask may be formed from a polymer, preferably an elastomer, using any of three disclosed die apparatuses.

Abstract: The invention is a flexible mask for use in charging a flowable material into selected cells of a honeycomb structure and is of particular utility in charging a sealing material into the ends of selected cells of such a structure during fabrication of solid particulate fitler bodies and other selectively plugged honeycomb structures. The mask has a central body with a set of openings extending therethrough which allow passage of the flowable material through to the selected cells and a second set of protrusions extending from one of the surfaces of the mask which are used to align the mask to the end face of the structure and which extend into and sealably cover the cells which are not to receive the flowable material. The mask may be formed from a polymer, preferably an elastomer, using any of three disclosed die apparatuses.

Abstract: A drilling rate and depth monitor is provided for determining the rate in which apertures are formed in a workpiece using an electro-chemical machining process. The drilling rate and depth monitor is particularly useful where the rate of aperture formation is extremely slow, i.e., less than one-thousandths of an inch per second. The drilling rate includes a position sensor coupled between a workholder and a movable member supporting a plurality of cathodic drilling tubes which yields a depth signal proportional to the distance between the drilling tubes and the surface of the workpiece. Differentiation means are responsive to the depth signal for producing a drilling rate signal and display means are provided for both the drilling rate and drilling depth.

Abstract: A monolithic refractory honeycomb filter of zircon or zircon plus an oxide additive is useful to remove impurities from molten metal, particularly from molten steel. The filter has a frontal contact surface containing the openings of a plurality of through-and-through cells for passage of the molten metal. Impurities adhere to the frontal contact surface of the filter and to the cell walls themselves.

Abstract: The invention is a flexible mask for use in charging a flowable material into selected cells of a honeycomb structure and is of particular utility in chraging a sealing material into the ends of selected cells of such a structure during fabrication of solid particulate filter bodies and other selectively plugged honeycomb structures. The mask has a central body with a set of openings extending therethrough which allow passage of the flowable material through to the selected cells and a second set of protrusions extending from one of the surfaces of the mask which are used to align the mask to the end face of the structure and which extend into and sealably cover the cells which are not to receive the flowable material. The mask may be formed from a polymer, preferably an elastomer, using any of three disclosed die apparatuses.

Abstract: A novel electrochemical cell including a solid electrolyte heated to an elevated temperature for operation and an integral cell electrode/heater for heating the electrolyte. Solid electrolyte embodiments are described. The integral electrode/heater is applied to a surface of the solid electrolyte and is resistively heated by an alternating electric current. A portion of the solid electrolyte may also be resistively heated. The described or comparable cells may be incorporated into an oxygen detector or similar apparatus where the apparatus is operated by alternately heating the cell and measuring the emf developed by the cell across its electrode.The invention is also, in part, a unique, solid electrolyte-integral cell electrode/heater configuration which provides a zone of uniform maximum heating at a predetermined location within the electrolyte and which, when used with a suitable resistive heating electric current, confines the current to the integral electrode/heater prolonging cell life.

Abstract: High surface area agglomerates of a porous oxide for the support of catalysts are provided. The agglomerates, in coarse particulate form, are incorporated into a sinterable ceramic structure as a discrete discontinuous phase. The agglomerates provide the high surface area necessary for effective catalyst support within the ceramic structure, which is sintered to provide appreciable density and strength.

Abstract: The invention includes a simple and inexpensive thermal controller and simple and inexpensive radio frequency alternating current generator which are provided in an improved temperature control system for a resistively heated electrochemical cell. The temperature controller is formed by a single amplifier with feedback circuit which provides the function of a combined deviation amplifier and two mode (percent proportional band and integral functions) controller. The alternating current generator uses a single direct current voltage source to generate a radio frequency alternating electric current. The two elements are combined in a temperature control circuit for a resistively heated electrochemical cell. The control circuit provides an alternating current with varying power by cyclicly shutting the current off for irregular portions of a predetermined cycle period.

Abstract: A method of preparing a monolithic catalyst support having an integrated high surface area phase is provided. A plasticized batch of ceramic matrix material intimately mixed with high surface area powder is formed into the desired shape for the monolith and then heated to sinter the ceramic. The resulting monolith has a strong substrate of the ceramic matrix material and a high surface area phase provided by the high surface area powder extruded with the batch.

Abstract: Monolithic catalyst support structures in which a support phase of high surface area oxide material is disposed on or within a sintered ceramic material are improved by using a mixture of alumina and silica as the high surface area oxide support phase. The mixtures of alumina and silica retain higher surface area, after firing or exposure to elevated service temperatures, than does either component individually, and thereby impart higher overall surface area to the monolithic support structures.

Abstract: A method of forming a monolithic ceramic catalyst support having a high surface area phase of porous oxide embedded within the monolith structure is provided. The porous oxide phase is incorporated into a sinterable ceramic structure as a discrete discontinuous phase. The high surface area necessary for effective catalyst support is thereby provided within the ceramic structure, which is sintered to provide appreciable density and strength.

Abstract: A catalyst support having both substantial high strength and high surface area can be produced by heating a shaped mixture of a porous oxide having a surface area of at least 20 m.sup.2 /g and the precursor of an inorganic binder for the porous oxide. The binders are precursors of alumina, silica, or titania, and are capable of imparting substantial strength to the support at relatively low firing temperatures.

Abstract: A liquid transfer ball formed from sintered zirconium oxide particles which exhibits utility as the ball element of a ball pen writing instrument to transfer ink from an ink reservoir to a writing surface such as paper. The ball exhibits a porosity of less than 8% by volume and is immune to corrosive action of inks.

Abstract: Ceramic body formed by reaction sintering at pressures ranging from subatmospheric to superatmospheric of admixed and shaped reactants, which can be elements, compounds, intermetallic compounds and/or alloys, in stoichiometric proportions to substantially form 10-90 mole percent of boride phase or phases of one or more of elements of Groups 3b including lanthanide and actinide series elements, 4b, 5b and 6b, and 10-90 mole percent of oxide phase or phases of one or more of elements of Groups 3a, 4a, 3b, 4b, 5b, 6b and 8, and which phases have a maximum grain size substantially not greater than 15 .mu.m. Body in a form for wear resistance and corrosion-erosion resistance has a virtual absence of open porosity, e.g. not greater than 5% or less than about 3%, and a Rockwell A hardness of greater than 90.

Abstract: Ceramic body formed by reaction sintering at pressures ranging from subatmospheric to superatmospheric of admixed and shaped reactants, which can be elements, compounds, intermetallic compounds and/or alloys, in stoichiometric proportions to substantially form 5-95 mole percent of nitride phase or phases of one or both of Al and Si, and 5-95 mole percent of second phase or phases being boride, carbide, silicide and/or sulfide of one or more of elements of Groups 3b including lanthanide and actinide series elements, 4b, 5b and 6b, which phases have a maximum grain size substantially not greater than 10 .mu.m and which body contains 0 to 4 weight percent oxygen.

Abstract: High purity alumina filters suitable for relatively high temperature molten metal filtering applications are prepared by providing a composition comprising fine grain reactive alumina and a burn out material in amounts sufficient to increase the porosity of the resulting filter structure, the composition being free of grain growth inhibitors in amounts sufficient to inhibit growth of the alumina grains during firing; forming the composition into a honeycomb structure by suitable means; and firing the structure beyond the temperature providing maximum densification of the reactive alumina employed whereby grain growth is fostered. The honeycomb structure is fired sufficiently long for significant growth of the particles (from sizes less than about 5 microns to sizes between 10 and 20 microns) and for the creation of wide grain boundaries between the resulting grains which further act as crack arrestors. A preferred composition includes 19 parts by weight reactive alumina, at least 99.5% pure Al.sub.2 O.sub.

Abstract: The invention comprises a method and various apparatus related to fabricating solid particulate filter bodies and other honeycomb structures the cells of which are selectively charged with a plugging or other flowable material. Solid coverings are applied over the end faces of a honeycomb structure, preferably an adhesive backed transparent thermoplastic film such as polyester, openings are created through the covering, preferably by melting the thermoplastic film, and the sealing or other flowable material is charged through the openings formed in the covering into the underlying cells.A porous walled honeycomb structure having coverings adhered to its end faces with selective openings therethrough is itself a solid particulate filter of some usage. A more substantial solid particulate filter body may be formed by charging a more durable sealant through the openings to form plugs and removing the coverings.

Abstract: The invention comprises a method and various apparatus related to fabricating solid particulate filter bodies and other honeycomb structures the cells of which are selectively charged with a plugging or other flowable material. Solid coverings are applied over the end faces of a honeycomb structure, preferably an adhesive backed transparent thermoplastic film such as polyester, openings are created through the covering, preferably by melting the thermoplastic film, and the sealing or other flowable material is charged through the openings formed in the covering into the underlying cells.A porous walled honeycomb structure having coverings adhered to its end faces with selective openings therethrough is itself a solid particulate filter of some usage. A more substantial solid particulate filter body may be formed by charging a more durable sealant through the openings to form plugs and removing the coverings.