An Investigation of Superplasticity in Nitride Ceramics

9314825慕克吉本研究的目的是研究一类重要的结构陶瓷，即氮化物陶瓷的超塑性现象。这是一项合作研究，导致了一个全面的框架，将粉末固结和微晶高密度氮化物陶瓷的形成与基于超塑性的制造工艺联系起来。这项研究的一个主要主题是了解亚微米非氧化物陶瓷材料的超塑性机理。以纯氮化铝(AIN)和氮化硅(SiN)为研究对象，不添加助熔剂，发展了非氧化物陶瓷超塑性响应的科学研究范式。这两种重要的氮化物陶瓷都将通过等离子活化烧结(PAS)工艺进行固化，该工艺最近在日本首创，并证明在极短的烧结时间内即可获得高密度。在这个日益注重能源的工业时代，陶瓷作为注定要用作高温结构材料的材料走在了前列。它们有潜力在燃气轮机发动机、推进系统和地面发电厂中找到自己的位置。超塑性带来了另一个吸引人的特点，即近净成形工艺，显著节省了材料和加工成本。

9314825 Mukherjee The purpose of this research is to investigate the phenomenon of superplasticity in an important class of structural ceramics, i.e., nitride ceramics. This is a collaborative investigation leading to a comprehensive framework connecting powder consolidation and formation of micrograined high density nitride ceramics to fabrication processes based on superplasticity. A major theme of the research is the understanding of the mechanisms of superplasticity in submicron non-oxide ceramic materials. Scientific paradigms relevant to superplastic response in non-oxide ceramics are developed by focusing the research on pure and doped aluminum nitride (AIN) and silicon nitride (SiN) and without fluxing additives. Both of these important nitride ceramics will be consolidated by a Plasma Activated Sintering (PAS) process very recently pioneered in Japan and demonstrated to achieve high densities in very short sintering times. %%% In this increasingly energy-conscious industrial age, ceramics are in the forefront as materials destined for use as high temperature structural materials. They have the potential for finding their place in gas turbine engines in propulsion systems and also in terrestrial power plants. Superplasticity brings the additional attractive feature of being a near net-shape forming process, with significant saving in materials and machining costs.