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

基本信息

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

项目摘要

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.

通过胶体定向凝固冰来加工高度多孔的陶瓷。冷冻干燥时，冰升华，在陶瓷中留下单向孔道。初步研究得出这样的假设：可以使用共晶微观结构的准规则定向凝固进行类比来理解孔隙形态。正在进行定量原位实验，直接观察移动凝固界面的形貌以及界面速度与冰晶间距之间的关系。这将使我们能够检查共晶凝固理论对胶体的适用性，并探索可加工的孔隙结构的范围。与此同时，正在建造一种“断电”凝固装置，以控制冷冻过程中较大块样品的温度梯度。这将使孔隙结构和加工变量（例如温度梯度、胶体中固体的体积分数和烧结温度）之间的定量关系得以确定。这项工作应该会产生一种新型的高孔隙率陶瓷，适用于一系列例如用于环境保护的陶瓷过滤器和用于组织工程和器官再生的陶瓷生物反应器。研究生和本科生将学习陶瓷加工的材料科学，并了解高多孔陶瓷的这些应用的要求。