Abstract: An improved gear micropump (10) for delivering corrosive materials, particularly photographic materials, such as dyes and emulsions, has a pair of intermeshing gears (16,18) rotatably mounted on zirconia ceramic shafts (24,26). The ceramic shafts of the invention may be formed from zirconia and zirconia composite materials. The gear micropump (10) having the zirconia ceramic shafts (24,26) eliminates pulsation during fluid delivery and is resistant to wear and abrasion. Moreover the zirconia ceramic shafts (24,26) are strongly resistant to chemicals like photographic emulsions and dyes and, therefore, do not contaminate product with corrosive materials.

Abstract: A method of making a hydrodynamic ceramic bearing includes the steps of providing ceramic powder comprising a first concentration of particulate aluminum oxide and a second concentration of particulate zirconium oxide alloy. The zirconium oxide alloy consists essentially of zirconium oxide and a the group consisting of MgO, CaO, Y.sub.2 O.sub.3, Sc.sub.2 O.sub.3, and rare earth oxides. The zirconium oxide alloy has a concentration of the secondary oxide of, in the case of Y.sub.2 O.sub.3, about 0.5 to about 5 mole percent; in the case of MgO, about 0.1 to about 1.0 mole percent, in the case of CeO.sub.2, about 0.5 to about 15 mole percent, in the case of Sc.sub.2 O.sub.3, about 0.5 to about 7.0 mole percent and in the case of CaO from about 0.5 to about 5 mole percent, relative to the total of the zirconium oxide alloy, the compacting further comprising forming a blank. A mold is provided for receiving and processing the ceramic powder thereby forming a ceramic billet.