化学气相沉积ZrC陶瓷涂层的微观结构和抗烧蚀性能

摘要

To improve the anti-ablative properties of carbon/carbon （C/C） composites, the controlled preparation of zirconium carbide （ZrC） coatings of superstoichiometric, stoichiometric, and substoichiometric compositions has been a chieved utilizing zirconium tetrachloride and propene precursor gases in an atmospheric pressure chemical vapor deposition system. The ablative properties of coated samples were tested in an oxy-acetylene torch system. The phase compositions and morphological features of the coatings were investigated pre- and post test. The results show that all types of ZrC coatings can protect C/C substrate from ablation. Due to individual microstructure feature, ZrC1.0 ＋ C, ZrC1.0 and ZrC0. 7 coatings have different ablation resistance and mechanisms. Of the three types of coatings, ZrC0.7 coating with microaggregatelike textures and fine grains acts as the best anti-ablation barrier which can reduce mass and linear ablation rates to 1.1 × 10 ^-4 g/cm^2 · s and 0.3 × 10^ -3 mm/s after 240 s＇ ablation.%为了提高碳／碳（C／C）复合材料的抗烧蚀性能，在C／C基体上成功制备了碳化锆（ZrC）高温抗烧蚀涂层。用常压化学气相沉积法，前驱体选用ZrCl4＋C3H6＋H2＋Ar体系。通过调节C3H6的流量，制得3种碳锆原子比的ZrC陶瓷涂层（ZrC1.0＋C，ZrC1.0，ZrC0.7）。分析了不同锆碳比ZrC涂层的相组成和形貌差异，研究了锆碳比对ZrC陶瓷涂层的烧蚀性能的影响。结果表明，3种ZrC涂层都可有效提高C／C复合材料的抗烧蚀性能，但由于微观结构特征不同，3种涂层显示不同的烧蚀性能和烧蚀机制。其中，ZrC0.7涂层试样烧蚀后，表面形成致密的氧化物层，烧蚀性能最佳，烧蚀240s后质量烧蚀率和线烧蚀率分别为1．1×10^-4g／cm^2·s和0．3×10^-3mm／s。