Abstract: In high-end industrial sectors such as aerospace and energy equipment there is an increasingly urgent demand for ceramic fiber materials with excellent thermal insulation properties and good flexibility under extreme high-temperature conditions. Traditional ceramic fibers have shown significant progress regarding high-temperature resistance and mechanical properties. Recently zirconia-based ceramic fibers have attracted considerable attention due to their ultra-high temperature limits extremely low thermal conductivity outstanding thermal stability and phase transformation strengthening effects. Collectively these characteristics demonstrate exceptional comprehensive performance and significant potential for engineering applications. This paper systematically reviews the progress of domestic and international research on the preparation of flexible zirconia-based fibers. It focuses on the principles and characteristics of mainstream spinning technologies including electrostatic spinning centrifugal spinning and dry spinning as well as their effects on the structural properties of the fibers. Electrostatic spinning technology is capable of producing continuous nanofibers with a uniform diameter distribution and a large specific surface area however it faces limitations in macroscale production efficiency and fiber strength. In contrast centrifugal spinning offers high preparation efficiency and is suitable for large-scale production of micrometer-scale fibers although there is still room for improvement in controlling fiber orientation. Dry spinning is compatible with certain polymer precursor systems and allows for good control of fiber morphology. However it does not enhance fiber orientation control during high-temperature firing and is susceptible to structural defects during high temperature sintering. In this paper the flexibility mechanism is elucidated as originating from microscale regulation achieved via doping. At the microscopic level doping regulates crystalline phases and alleviates stress through optimization. At the mesoscopic level it controls grain size and suppresses intergranular cracking. Ultimately at the macroscopic level it achieves collaborative energy dissipation through synergistic interactions between the fibers and their network structure. By regulating the spinning process it is possible to optimize the internal grain size pore distribution and phase composition of the fibers thus balancing their thermal insulation and flexibility. Under extremely high temperatures strong thermal shocks and complex stress environments these materials demonstrate good structural integrity and thermal stability indicating broad application prospects in aerospace thermal protection systems high-thrust-to-weight-ratio engine insulation high-temperature pipeline insulation for energy equipment and key components of next-generation nuclear energy systems. Despite significant advancements in the research of flexible zirconia-based fiber materials several challenges remain in their practical engineering applications including insufficient long-term thermal stability loss of flexibility in high-temperature environments immaturity of continuous preparation technology and high production costs. Future research should prioritize the optimization of fiber formation and the exploration of multiscale structural control strategies to enhance the overall performance and durability of these fibers. Additionally efforts should aim to the advance the preparation process towards environmentally friendly cost-effective and large-scale production. Promoting the integrated design of material structure and function will further accelerate the application of flexible zirconia-based ceramic fibers in high-end equipment.

Key words: zirconia ceramic fiber, preparation method, structural regulation, flexible mechanism

摘要： 聚焦柔性氧化锆基陶瓷纤维,首先综述其制备方法和结构特点,并对比各类制备技术的优势与局限。 其次,重点分析其柔性表征方法及调控机制。 此外,阐述了其结构特性及在热防护、吸音、高温过滤和复合材料等领域的应用前景。 最后,探讨了规模化制备与性能优化的发展趋势。 综述结果可为柔性陶瓷纤维的设计提供新的参考。

关键词: 氧化锆, 陶瓷纤维, 制备工艺, 结构调控, 柔性机制