Rapid Plasma Sintering of B"-Alumina

点击翻译按钮获取中文摘要

9529646 Johnson This is a renewal proposal based on the results and accomplishments of an ongoing NSF-DMR project, which demonstrated that microwave and RF plasma heating enhanced densification of -alumina with a significant reduction in sintering temperature. The PI will extend the previous work to a fundamental investigation of rapid sintering and microstructure development of -alumina utilizing microwave excited plasmas. Preliminary results show that plasma sintering will alleviate the problems of loss of volatile components in - alumina without costly encapsulation. Moreover, the plasma sintering configuration is ideally suited for the rapid and continuous sintering of tubes, which should improve product uniformity. The proposed research is focused on the scientific issues that govern the sintering characteristics of ceramics containing volatile components, such as sodium and lithium in -alumina, which limit the technological feasibility of -alumina as an electrolyte for sodium-based battery applications. The following objectives will be pursued: 1. Investigate sintering of -alumina under microwave excited plasma, with and without grain boundary dopant additions. 2. Quantify the microstructure development under plasma sintering conditions using an arsenal of ion, electron, and photon beam techniques. 3. Elucidate the role of grain boundary dopants used to manipulate the microstructure and alter the grain boundary ionic conductivity. %%% The outcome of the proposed research will shed light on the potential for plasma sintering of ceramics containing volatile components in general, and -alumina in particular. The ultimate objective of our undertaking is to dramatically reduce the processing cost and increase the performance and reliability of -alumina to a point that it is attractive for commercial application in sodium-based batteries and other applications of sodium ionic conductors. ***