有机无机转化法制备超高温陶瓷基复合材料技术研究

Research of ultra-high temperature ceramic matrix composites prepared by organic-inorganic transformation

超高温陶瓷基复合材料是以连续碳纤维为增强体、超高温陶瓷为基体的一类复合材料,具有密度低、韧性好、耐高温、抗氧化及耐烧蚀等优异性能,在新型高速飞行器热结构应用方面有着不可替代的作用。碳纤维增强体和陶瓷基体是超高温陶瓷基复合材料的两个重要组成部分,对复合材料使役性能起着决定性作用,但是,碳纤维与陶瓷基体的理化性质差异大,如何将碳纤维与陶瓷基体进行有效复合,以便充分发挥碳纤维轻质、高强韧特性与陶瓷基体抗氧化、耐烧蚀特性,是超高温陶瓷基复合材料基础研究和工程应用需要解决的主要问题。本文论述了有机无机转化法制备超高温陶瓷基复合材料技术的发展思路,介绍了超高温有机陶瓷前驱体的设计与合成、C/ZrC-SiC和C/HfTaC-ZrC-SiC复合材料的研究结果,探讨了解决新型高速飞行器高温气动/燃气环境氧化烧蚀问题的材料技术方案,为连续纤维增强超高温陶瓷基复合材料的技术发展和工程应用提供借鉴.

Ultra-high temperature ceramic matrix(UHTC) composites play a key role for the application of thermal structures of high-speed launch vehicle due to their lightweight, high melting point, high specific strength/stiffness and excellent anti-oxidation/ablation resistance. It is known that UHTC composites consist of carbon fiber reinforcement and ultra-high temperature ceramic matrix, where reinforcement and ceramic matrix possess different physical and chemical properties. To make better performance of UHTC composites, it is quite necessary to think about how to incorporate carbon fiber with ceramic matrix effectively, where the advantages for both fiber and matrix should be taken into accounts. In order to provide a guidance for the fundamental research and engineering application of UHTC composites, in this paper, the synthesis of precursors and the performance of C/ZrC-SiC and C/HfTaC-ZrC-SiC composites are reviewed. And then the technical route for the fabrication of UHTC composites via organic-inorganic transformation is proposed. It is expected to overcome the main issues which encountered in the development of composite design and fabrication.