SBIR Phase I: Advanced, Polycrystalline t'-Zirconia Ceramics for High Temperature Applications

*9660417 JUE这个第一阶段的小型企业创新研究项目将制造用于高级应用的多晶t‘-氧化锆陶瓷。多晶t‘-氧化锆在制备工艺和性能上都不同于常规的四方(t相)氧化锆(TZP)。TZP陶瓷在~1500℃下烧结，具有高强度、高韧性，但蠕变抗力低，低温老化。T‘-氧化锆在较高温度下烧结，具有中等强度、高韧性、高抗蠕变性能，且不存在低温老化。抗蠕变和低温老化性能使t‘-氧化锆陶瓷在许多低温和高温应用中优于TZP。通过2000℃以上的高温直接电阻加热和表面冷却，可制得表面晶粒细小的多晶t‘-氧化锆陶瓷。第一阶段将制造高抗蠕变、高强度、高韧性和抗相变的氧化锆陶瓷。将制造和评估t‘-氧化锆制热元件。多晶氧化锆陶瓷的潜在商业应用包括：(1)炉子加热元件，(2)耐火材料，(3)窑具，(4)要求耐水、酸、碱侵蚀的化学反应器衬里，(5)储存加热器，(6)超导体衬底，以及(7)要求高蠕变性能的结构部件。

*** 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.