The Processing of Highly Porous Ceramics by Analogy with Quasi-Regular Eutectic Structures

类比准正则共晶结构高孔陶瓷的加工

• 批准号: 0404874
• 负责人: Ian Nettleship
• 金额: $ 25.96万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-08-01 至 2009-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0404874&HistoricalAwards=false
• 关键词: Processing; Highly; Porous; Ceramics; Analogy

Highly porous ceramics are being processed by the directional solidification of ice through colloids. On freeze drying the ice sublimes leaving unidirectional pore channels in the ceramics. Preliminary studies have lead to the hypothesis that the pore morphologies can be understood using an analogy with quasi-regular directional solidification of eutectic microstructures. Quantitative in situ experiments are being conducted to directly observe the morphology of the moving solidification interface and the relationship between the interfacial velocity and the spacing of the ice crystals. This will allow us to examine the applicability of eutectic solidification theory to colloids and explore the range of pore structures that could be processed. At the same time a "power-down" solidification apparatus is being built to control the temperature gradient across larger bulk samples during freezing. This will enable quantitative relationships to be determined between the pore structure and processing variables such as temperature gradient, the volume fraction of solids in the colloid and the sintering temperature.The work should result in a new class of high porosity ceramics suitable for a range of applications such as ceramic filters for environmental protection and ceramic bioreactors for tissue engineering and organ regeneration. Graduate and undergraduate students will learn the materials science of ceramics processing and develop an appreciation of the requirements for these applications of highly porous ceramics.

高度多孔的陶瓷是通过冰通过胶体的定向凝固来加工的。 在冷冻干燥时，冰升华，在陶瓷中留下单向孔通道。 初步的研究已经导致的假设，可以理解的孔的形态，用准规则的定向凝固的共晶显微组织的类比。 定量原位实验直接观察移动凝固界面的形态以及界面速度与冰晶间距之间的关系。 这将使我们能够研究共晶凝固理论对胶体的适用性，并探索可以加工的孔结构的范围。 与此同时，正在建造一个“断电”固化装置，以控制冷冻过程中较大体积样品的温度梯度。 这将使定量关系之间的孔隙结构和加工变量，如温度梯度，胶体中的固体的体积分数和烧结temperature.The工作应导致一类新的高孔隙率陶瓷适用于一系列的应用，如陶瓷过滤器的环境保护和陶瓷生物反应器的组织工程和器官再生。 研究生和本科生将学习陶瓷加工的材料科学，并对高度多孔陶瓷的这些应用的要求有所了解。