C／C—ZrC复合材料高温氧乙炔焰烧蚀性能及机理研究

摘要

采用基体改性技术将ZrC引入C／C复合材料中，制备了一种新型的C／C—ZrC复合材料。通过氧乙炔焰烧蚀实验，研究了ZrC含量及烧蚀时间对C／C—ZrC复合材料高温耐烧蚀性能的影响。用XRD和TEM对烧蚀后材料的相组成和微观结构进行了分析，结果表明，ZrC被氧化的主要生成物为ZrO2，伴有少量ZrC和C，含26．46％ZrC的C／C—ZrC复合材料，在氧乙炔焰烧蚀50s后，在材料表面生成致密的ZrO2膜，阻挡了氧对基体的扩散，并有隔热作用，有效保护复合材料被烧蚀和冲刷。实验表明，复合材料在高温氧乙炔焰烧蚀20s后，线烧蚀率和质量饶蚀率分别为0．012mm／s和0．0033g／s，比C／C复合材料分别降低7．6％和50％。%To improve the ablation resistance of C/C composites in severe environment, C/C-ZrC composites were fabricated by inner-modification method via introducing ZrC into C/C composites. The effect of ZrC content and ablation time on ablation property of C/C-ZrC composites was investigated by oxyacetylene torch flame test, and the structure of C/C- ZrC composites after ablation was studied by XRD and SEM analysis. The results show that the introduction of ZrC into C/ C composites can effectively reduce the linear ablation rate and mass ablation rate of C/C composites, and relative high ZrC content is favorable for improving the ablation resistance of C/C composites. As ablation time increased, the linear ablation rate and mass ablation rate are further reduced. The improvement of ablation resistance is mainly attributed to the formation of ZrO2 films in the ablation process.