Twinning, Phase Transformations, and Film Formation of Zirconia-based Ceramics

氧化锆基陶瓷的孪生、相变和成膜

• 批准号: 9628694
• 负责人: Arthur Heuer
• 金额: $ 42万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9628694&HistoricalAwards=false
• 关键词: Twinning; Phase; Transformations; Film; Formation

9628694 Heuer The proposed research contains three topics: i) Deformation twinning in undoped monoclinic zirconia (m-ZrO2 ) single crystals and polycrystals as a function of load, orientation and temperature will be studied using microhardness indentation. At temperatures up to 1100C, m-ZrO2 is the stable phase. The competition between indent-induced slip and twinning will be studied; ii) Heating these crystals into the tetragonal (t) phase field will allow similar studies in t-ZrO2; here, the emphasis will be on slip systems, the competition between slip and ferroelastic deformation, and the role the indentation damage plays in nucleating the martensitic t to m transformation on cooling; iii) A bio-inspired chemical route to thin film formation of pure and Y203-doped ZrO2 has been discovered. The aqueous chemistry needed to optimize film formation will be systematically studied.. Deposition of ZrO2-based films on semiconductor grade Si and Ni-base alloys have implications for oxygen sensors and thermal barrier coatings, respectively. The proposed research will examine the fundamental mechanical behavior of zirconia-based ceramics. Zirconia has been used as a model system for understanding toughening in a number of other tough ceramics. This proposal includes three research topics: deformation twinning in 1) monoclinic and 2) tetragonal zirconia studied by microhardness indentation, and 3) a study of the chemistry to optimize the deposition of self-assembling thin films of zirconia-based ceramics. Understanding these self- assembling films has the potential to enable materials researchers to deposit a film of any material on any substrate.

本研究包括三个主题：i)利用显微硬度压痕研究未掺杂单斜氧化锆（m-ZrO2）单晶和多晶的变形孪晶随载荷、取向和温度的变化。在温度高达1100C时，m-ZrO2是稳定相。研究了缩进滑移与孪生之间的竞争关系；ii)将这些晶体加热到四方(t)相场将允许在t- zro2中进行类似的研究；这里，重点将放在滑移系统，滑移和铁弹性变形之间的竞争，以及压痕损伤在冷却时马氏体向m转变成核中的作用；iii)发现了纯ZrO2和y203掺杂ZrO2薄膜形成的仿生化学途径。优化成膜所需的水化学将被系统地研究。在半导体级Si和ni基合金上沉积zro2基薄膜分别对氧传感器和热障涂层具有重要意义。提出的研究将检查锆基陶瓷的基本力学行为。氧化锆已被用作模型系统来理解许多其他坚韧陶瓷的增韧。本课题包括三个研究课题：1)单斜和2)用显微硬度压痕研究四边形氧化锆的变形孪晶；3)优化氧化锆基陶瓷自组装薄膜沉积的化学研究。了解这些自组装薄膜有可能使材料研究人员能够在任何衬底上沉积任何材料的薄膜。