发泡-注凝成型制备钇稳定氧化锆多孔陶瓷及其在热环境下的微结构演变研究

Yttria-stabilized zirconia porous ceramic has outstanding attributes of high specific strength, high melting point, excellent corrosion resistance, low thermal conductivity and good chemical stability. These advantages made it potential to aim at multifunctional material, characterized by lightweight, high strength, efficient heat insulation and long service life. Unfortunately, its application is prohibited by microstructure degradation evolution under service thermal environment. Then it is difficult to balance the key thermal and mechanical properties. In fact, the composition and micro-structural characteristics of YSZ porous ceramic depend on its comprehensive properties and durability. We propose to accurately control and design the microstructure of YSZ porous ceramic by foam-gelcasting, using a novel Isobam gelling system which has advantages of low addition and easy operation. Then, we will disclose microstructure evolution of YSZ porous zirconia under repeated heating and cooling environment using multi-scale analysis methods. On the other hand, correlation will be established between microstructure evolution, compressive strength and effective thermal conductivity of material from theoretical analysis and experimental demonstration perspectives. Finally, this study clarifies matching strategy between thermal and mechanical properties of porous ceramic after disclosing the relationship of thermal environment, microstructure evolution and property variation. The results achieved in this project will strengthen understanding of microstructure regulation for porous ceramic, and provide theoretical guidance for solving the problems of restriction between thermal and mechanical properties, and short service life in thermal insulation material during high temperature environment.

钇稳定氧化锆(YSZ)多孔陶瓷具有高比强度、低热导率、耐高温、耐腐蚀和高化学稳定性等优点，是最具潜力发展成为兼具轻质高强、高效隔热和长寿命特性的功能材料，但其应用受阻于服役热环境下微结构劣化演变，导致关键热/力性能相互制约难以兼顾。由于YSZ多孔陶瓷的综合性能和耐久性取决于其组成和微结构特征。因此，本项目拟采用添加量少、操作方便的新型Isobam凝胶体系，发泡-注凝成型调控和设计YSZ多孔陶瓷的微结构，运用跨尺度的微结构分析手段，研究材料在具有代表性的循环加热冷却热环境中微结构演变特征及规律；从理论分析和实验论证两个角度探明材料的微结构演变与压缩强度、有效热导率变化的对应关系；通过绘制出热环境-微结构演变-性能变化的关系图，揭示材料的热/力性能匹配规律。研究成果将进一步丰富多孔陶瓷的微结构控制理论，为解决保温隔热材料在热环境中热/力性能难以兼顾、耐久性差等问题提供理论指导。

开发具有高比强度、低热导率、耐高温、耐腐蚀和高化学稳定性等优点的多孔陶瓷，已引起材料领域同行的广泛关注。剖析轻质高强、低热导率的氧化钇稳定的氧化锆(YSZ)多孔陶瓷在热环境下微结构演变特点和性能衰退规律，对推动高效隔热和长寿命特性的保温功能材料具有重要意义。本项目已采用添加量少、操作方便的新型Isobam凝胶体系，运用发泡-注凝成型调控和设计出不同孔隙结构特点与微结构特征要求的YSZ多孔陶瓷，运用跨尺度的微结构分析手段，研究材料在具有代表性的循环加热冷却热环境中微结构演变特征及规律；从理论分析和实验论证两个角度探明了材料的微结构演变与压缩强度、有效热导率变化的对应关系；并绘制出热环境-微结构演变-性能变化的关系图，已初步揭示材料的热/力性能匹配规律。通过本项目的实施，还详细验证了Isobam凝胶体系在铁氧体多功能陶瓷浆料制备的可行性，为这些多孔功能材料在实验室及未来工业应用提供实验依据。