Abstract: A ceramic article containing a core/bulk comprising tetragonal zirconia or tetragonal zirconia and alumina composite wherein zirconia is preferably doped with yttria, and a shell/surface comprising zirconium boride.

Abstract: A method for making a dielectric member with an integral, electrically conductive surface is made by molding a substrate from a zirconia alloy powder using a tape casting process. The resulting green substrate is sintered and after sintering may be cut to the final desired size and shape. Once the insulating ceramic substrate has been formed, the surface of the substrate is modified using infrared laser energy. Through the impingement of infrared laser radiation upon the surface of the ceramic substrate, an electrically conductive region is produced on the surface of the substrate. In such manner, the entire surface can be made electrically conductive or a particular pattern can be traced. As an integral part of the substrate, the surface will not delaminate from the substrate. Further, because the modified surface region and the substrate are both a zirconia, the coefficients of thermal expansion of the substrate and the modified surface region will be closely matched.

Abstract: Electrically conductive ceramic composite articles comprising tetragonal zirconia or a composite of zirconia-alumina and zirconium diboride.

Abstract: An alumina ceramic article and a method for preparing the article. The method comprises the steps of:(1) Compacting a mixture of a first concentration of particulate aluminum oxide sufficient to prevent retention of the zirconium oxide alloy particles in the shell in a predominantly tetragonal crystal structure and a second concentration of particulate zirconium oxide alloy. The zirconium oxide alloy is zirconium oxide and a secondary oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, CeO.sub.2, and rare earth oxides having a concentration of secondary oxide generally of about 0.5 to about 5 mole percent Y.sub.2 O.sub.3, from about 0.1 to about 1 mole percent MgO, from about 0.5 to about 15 mole percent CeO.sub.2, from about 0.5 to about 7.0 mole percent Sc.sub.2 O.sub.3, or from about 0.5 to about 5 mole percent CaO, relative to the total of the zirconium oxide alloy. The compacting results in the formation of a blank.

Abstract: A ceramic article containing a core comprising zirconia and ZrB.sub.2 composite wherein zirconia is preferably doped with yttria, and a shell comprising zirconium nitride.

Abstract: A method for preparing a ceramic article comprising compacting a particulate alloy of a primary oxide and a secondary oxide to form a blank, and sintering the blank in contact with substantially pure zirconium oxide. The primary oxide is zirconium oxide and the secondary oxide is selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, rare earth oxides and combinations thereof. Ceramic articles produced have tetragonal phase cores and monoclinic cases.

Abstract: A method for preparing a ceramic article comprising compacting a particulate alloy of a primary oxide and a secondary oxide to form a blank, and sintering the blank in contact with substantially pure zirconium oxide. The primary oxide is zirconium oxide and the secondary oxide is selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, rare earth oxides and combinations thereof. Ceramic articles produced have tetragonal phase cores and monoclinic cases.

Abstract: A method for preparing a ceramic article, the method comprising the steps of:1) compacting a mixture of particulate zirconium diboride and a zirconium oxide or zirconium oxide alloy or composite thereof which results in the formation of a block and2) sintering the block in a mixture of nitrogen and hydrogen to form a ceramic with a core comprising zirconia and a shell comprising zirconium nitride.

Abstract: Trolley wheels and guide rollers for a monorail trolley system and a method for reducing debris originating from trolley wheels and guide rollers particularly in the production environment of producing iron-sensitive photographic materials.

Abstract: A corrosion-resistant pump for propelling a fluid therethrough, the pump comprises a first magnet for providing a magnetic field. A motor is attached to the first magnet for rotating the magnet. A container is placed adjacent said first magnet for preventing the fluid contained therein from contacting the motor and the first magnet. A second magnet is disposed within the container and magnetically interacting with the first magnet which interaction, in turn, causes the second magnet to rotate simultaneously with rotation of the first magnet. The second magnet is coated with a ceramic magnetic material on its first portion and a bulk ceramic magnet attached to its second portion for preventing corrosion of the magnet and enhancing magnetic flux with the second magnet. A propeller is disposed within the container, and is attached to and simultaneously rotates with the second magnet for propelling the fluid through the container.

Abstract: The present invention relates to writing and marking images on ceramic surfaces in a reversible fashion. The images are marked using a laser. The images are erased by heating the ceramic surfaces to a temperature of approximately 200.degree. C. or using a CO.sub.2 laser.

Abstract: An apparatus for selectively inverting an external magnetic field in a magneto-optic recording system so that information can be selectively recorded on or erased from a magneto-optic recording element of the system moving through the field, the apparatus comprises a permanent magnet including a first and second portion positioned adjacent to each other and each portion having north and south poles oriented along their cross-sectional dimension, wherein the north pole of the first portion is abuttingly adjacent to the south pole of the second portion, and the south pole of the first portion is abuttingly adjacent the north pole of the second portion; and a coil for imparting a magnetic field to the permanent magnet for moving the permanent magnet.

Abstract: A ceramic conveyance roller having a tetragonal phase crystal grain structure includes zirconium oxide and yttria and the molar ratio of yttria to zirconium oxide of from about 3:97 to about 5:95. The outer surface of the ceramic roller has a dimensional tolerance of less than 0.003 inches and the inner surface has a dimensional tolerance of less than 0.0005 inches. The outer surface of the roller can be modified to the cubic phase crystal grain or the monoclinic phase crystal grain.

Abstract: A coating apparatus (10) for coating a radiation-sensitive emulsion (30) on a photographic support (24) is fabricated from hopper bars (12) having a ceramic coating surface (20). An initial surface finish treatment is first applied to the ceramic coating surface, after which the coating surface is polished, to decrease the roughness of the coating surface sufficiently to prevent the formation of streaks in the emulsion coating layer or layers on the support.

Abstract: A process for producing a zirconia ceramic having a tetragonal phase crystal grain structure includes compacting a powder including zirconium oxide and dopant in the presence of binder to form a green part; and sintering the green part. The part is sintered and cooled at specific rates in specific increments to obtain the tetragonal crystal structure.

Abstract: A method for preparing a ceramic article comprising compacting a particulate including a primary oxide and a secondary oxide to form a blank. The primary oxide is ZrO.sub.2. The secondary oxide is selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, rare earth oxides and combinations thereof. The blank is sintered in contact with oxide selected from the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3 and rare earth oxides. The zirconia alloy ceramic articles produced have a cubic phase case and a tetragonal phase core.

Abstract: A zirconia ceramic having a tetragonal phase crystal grain structure and a process for producing same. The ceramic comprises zirconium oxide and a dopant that is an oxide of a rare earth element, calcium, or magnesium, or mixtures thereof, and the ceramic has a molar ratio of dopant to zirconium oxide in the range of from above about 3:97 to about 5:95 when the ceramic comprises less than about 0.5 mole percent of the oxide of magnesium, the ceramic has a molar ratio of dopant to zirconium oxide in the range of from about 0.5:99.5 to about 1.0:99.0 when the ceramic comprises from about 0.5 mole percent to about 1.0 mole percent of the oxide of magnesium, and the ceramic does not comprise more than about 1.0 mole percent of the oxide of magnesium.

Abstract: A method for preparing a ceramic article comprising compacting a particulate including a primary oxide and a secondary oxide to form a blank. The primary oxide is ZRO.sub.2 and the secondary oxide is MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, rare earth oxides or a combination thereof. The blank is sintered in contact with MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, rare earth oxides or a combination thereof. The zirconia alloy ceramic articles produced have a cubic phase case and a tetragonal phase core.

Abstract: A pump 10 for materials having a viscosity up to about 3.0.times.10.sup.5 cps, such as cellulose acetate, has a pump body 12 formed with a gear receiving means and, mounted thereon for closing the gear receiving means 13, a pair of side plates 16, 18 having bearing receiving cavities 21. The side plates 16, 18 have pressure relief means 50 for relieving pressure that builds-up in the intermesh of gears 14 when highly viscous material, such as cellulose acetate, is being pumped. This means of diverting the pressure buildup enables the pump 10 and component parts, such as shafts 22, 24 and plain bearings 20, to resist premature failure due otherwise to the resultant load caused by residual pressure buildup. In the preferred embodiment, wear resistant ceramic plain bearings 20 are press fitted in the bearing cavities. Grooves or channels 30 in the interior walls 32 of bearings 20 provide a means to lubricate shafts 22, 24 rotatably supported in the bearings 20.

Abstract: An ambipolar electrophotographic plate and materials used in the manufacture thereof including a photoconductive layer formulated of selenium, selenium-arsenic alloy or selenium-arsenic-tellurium alloy containing indium as a dopant which extends the range for electrons without noticeable deterioration of the long range for holes.