纳米结构陶瓷具有优异的性能，在诸多领域有潜在的应用价值。传统工艺以纳米粉体为原料，不仅价格昂贵、易受污染，而且难以抑制晶粒在烧结过程中的快速生长。因此，本项目提出以微米粉体为原料，利用放电等离子烧结初期产生的晶粒细化效应制备纳米结构陶瓷来解决这一难题。在深入研究氧化铝原料晶粒尺寸和烧结条件等对晶粒细化影响的基础之上，分析放电等离子烧结过程中产生晶粒细化的决定性因素，解决放电等离子烧结过程中的晶粒细化机理和晶粒尺寸控制技术等关键科学问题，进一步揭示放电等离子烧结氧化铝的原理，为工艺优化和材料设计提供指导。本项目在发展以微米氧化铝粉体为原料制备纳米结构陶瓷的新工艺，以及研究放电等离子烧结中的晶粒细化机理方面具有创新性。本项目的研究成果将对放电等离子烧结工艺的认识产生突破，对材料制备技术的进步具有重大意义。

Synthesis of nanostructured ceramics (grain size < 100 nm) has attracted extensive attentions due to their unique and superior properties, as well as their potential applications in many fields. The traditional　methods　have a common drawback that is the requirement of starting from nano-sized powders, which are hard to process and contain unwanted contaminations due to high surface-to-volume ratio. In addition, completely suppressing the grain growth during sintering is impossible．The research objective of this project is to develop a field-activated processing technology for synthesizing bulk nanostructured ceramics from micrometer-sized starting powders， via a so-called grain refining effect.　We study on the effect of starting particle size and sintering parameters on the grain refining of SPS sintered alumina. Based on these studies, the relationships between the processing and structures during grain refining will be built, which will be served as a scientific guideline for further design and applications of the materials. It is anticipated that the proposed research will develop a new route for making nanostructured ceramics from micrometer-sized powders, and uncover the mechanisms associated with the grain refining during SPS. Therefore, the successful delivery of the proposed research will significantly advance the fundamental understanding of SPS, as well as enhance the processing technology of materials.