碳／碳复合材料的宽温域自愈合抗氧化

在前期碳材料自愈合抗氧化研究的基础上，提出了通过多元陶瓷基体改性赋予碳／碳复合材料在较宽温度范围内实现自愈合抗氧化的基本原理和技术方案，分析了B4C—SiC、ZrC—SiC和ZrB2-ZrC—SiC等多元陶瓷的抗氧化机理，并采用新近合成的ZrB2-ZrC—SiC三元复相陶瓷有机前驱体，通过PIP技术制备了一系列超高温复相陶瓷改性的碳／碳复合材料，研究了该类复合材料在2200℃以下高速气流冲蚀环境中的协同抗氧化和抗烧蚀性能，发现材料表面生成的复合氧化物层能够在一定条件下赋予复合材料自愈合抗氧化能力。

Self-Healing Oxidation Resistance of C/C Composite Covering a Broader Temperatures Range

Mechanism of self-healing oxidation resistance and preparation technique of a kind of carbon fiber reinforced pyrolytic carbon composite （C/C） are suggested in the study. The composite characterized with homogeneous nano-dispersed complex matrix of ZrB2-ZrC-SiC was prepared by polymer impregnanting and pyrolysis （PIP） process, i.e. the nano-dispersed ZrB2-ZrC-SiC composite ceramics were introduced into a porous C/C composites with low density using complex precursors prepared by completely dissolving of ZrB2 , ZrC polymeric precursors and polycarbosilanes in dimethylbenzene solution. Ultra-high temperature ablation tests shown that the linear and mass ablation rate at 2 200 ℃ for the C/ C-ZrB2-ZrC-SiC composites decreased by 85.8% and 71.0% , respectively, in comparison with those of C/C-SiC composites. The very low ablation rates result from the formation of uniformly distributed ZrO2-SiO2 continuous glass coating, which prevented the molecular inner-diffusion of oxygen and thereby protected the carbon phase from being further oxidized.