TiC-TiB_2/Cu复合材料的抗热震及抗烧蚀行为研究

Study on the behavior in thermal shock and ablation resistance of TiC-TiB2/Cu ceramic-matrix composite

采用SHS/PHIP工艺制备了TiC-TiB_2/xCu复合材料,分析了材料的组成及显微结构,利用等离子火炬加热器考察了材料的抗热震及抗烧蚀性能。结果表明,随着金属Cu含量的增加,TiC-TiB_2/xCu复合材料的抗热震性增强,而抗烧蚀性能降低;在经过15s烧蚀后,材料的质量损失为1.7g,质量烧蚀率为0.11g/s。材料的抗烧蚀机理为耐高温、耐冲刷的高强度陶瓷骨架以及高温下挥发吸热的金属Cu粘接剂,二者的综合作用使材料具有抗烧蚀性。

The TiC-TiB2/xCu ceramic-matrix composites were produced by self-propagating high-temperature combustion synthesis combined with pseudo hot isostatic pressing (SHS/PHIP). The microstructure and the components of the synthesized compacts were analyzed. To investigate their behaviors of ablation resistance, the TiC-TiB2/xCu cermets were heated with plasma torch. The results showed that along with the increase of the Cu content, the thermal shock resistance of the TiC-TiB2/xCu was enhanced, but the ablation resistance descended. The loss mass of the cermet after ablation for 20 seconds was 1.7 g and the mass loss ratio was 0.ll g/s. The ablation resistance was obtained due to the combined action of both the high strength cermet with the durability to erosion and high temperature and the metal binder Cu of performing decalescence and volatilization at high temperature.