*** 9660417 Jue This Phase I Small Business Innovation Research project will fabricate polycrystalline t'-zirconia ceramics for advanced applications. Polycrystalline t'-zirconia differs from regular tetragonal (t-phase) zirconia (TZP) in both fabrication procedure and properties. TZP ceramics are sintered at ~1500(C, exhibit high strength, high toughness, but exhibit low creep resistance, and low temperature aging. t'-zirconia are sintered at higher temperatures, exhibit moderate strength, high toughness, high creep resistance, and no low temperature aging. Resistance to creep and low temperature aging makes t'-zirconia ceramics superior to TZP for many low and high temperature applications. Polycrystalline t'-zirconia ceramics of a fine surface grain structure will be made by high temperature direct resistive heating above 2000(C and surface cooling. Highly creep resistant, strong, tough and transformation-resistant zirconia ceramics will be fabricated in Phase I. Heating elements of t'-zirconia will be fabricated and evaluated The potential commercial applications of polycrystalline t'-zirconia ceramics include: (1) heating elements for furnaces, (2) refractories, (3) kiln furniture, (4) liners for chemical reactors requiring resistance to attack by water, acids, alkalis, (5) storage heaters, (6) substrates for superconductors, and (7) structural components requiring high creep resistance.
