Rapid Plasma Sintering of B"-Alumina

这是一个基于正在进行的NSF-DMR项目的结果和成就的更新提案，该项目表明微波和射频等离子体加热增强了-氧化铝的致密性，并显著降低了烧结温度。PI将扩展先前的工作到利用微波激发等离子体快速烧结和-氧化铝微观结构发展的基础研究。初步结果表明，等离子烧结可以减轻氧化铝中挥发性成分损失的问题，而无需昂贵的封装费用。此外，等离子体烧结配置非常适合快速和连续烧结的管，这应该提高产品的均匀性。提出的研究重点是控制含有挥发性成分的陶瓷烧结特性的科学问题，例如-氧化铝中的钠和锂，这限制了-氧化铝作为钠基电池电解质应用的技术可行性。将追求下列目标：研究了在微波激发等离子体下添加晶界掺杂和不添加晶界掺杂的-氧化铝烧结过程。2. 量化在等离子烧结条件下的微观结构发展，使用离子，电子和光子束技术的兵工厂。3. 阐明晶界掺杂剂在控制微观结构和改变晶界离子电导率方面的作用。提出的研究结果将阐明等离子烧结含有挥发性成分的陶瓷的潜力，特别是-氧化铝。我们的最终目标是大幅降低加工成本，提高-氧化铝的性能和可靠性，使其在钠基电池和钠离子导体的其他应用中具有商业应用吸引力。＊＊＊

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. ***