CVD法制备ZrC涂层与ZrC-TaC共沉积涂层的烧蚀性能

采用ZrCl_4-CH_4-H2-Ar与ZrCl_4-TaCl_5-CH_4-H_2-Ar反应体系,用化学气相沉积(CVD)制备ZrC涂层与ZrC-TaC共沉积涂层,并对其进行氧-乙炔焰烧蚀试验研究。利用X射线衍射(XRD)和扫描电镜(SEM)等分析技术对烧蚀前后ZrC与ZrC-TaC共沉积涂层的相组成及微观结构进行表征,并分析2种涂层的烧蚀机理。结果表明:ZrC涂层为细柱状晶体组织,ZrC-TaC共沉积涂层为ZrC与TaC成分周期性波动自组装多层复合结构,具有良好的组织结构可控性。经过60s氧-乙炔焰烧蚀试验,ZrC-TaC复相涂层表现出良好的抗热震性和整体完整性,与基体连接良好,无剥蚀和脱落,烧蚀性能明显优于单一ZrC涂层的烧蚀性能。ZrC-TaC复合涂层线烧蚀率和质量烧蚀率分别为5.3×10-5mm/s和3.2×10-5g/s,表现出良好的抗烧蚀性能。

Ablation properties of ZrC coating and ZrC-TaC co-deposition coating Fabricated by CVD

ZrC and ZrC-TaC coatings were deposited by chemical vapor deposition (CVD) using a gas mixture of ZrCl4, TaCl5, H2, CH4 and Ar. The microstructure and ablation properties of ZrC and ZrC-TaC coatings were characterized by X-ray diffraction, scanning electron microscopy and oxyacetylene torch ablation test. The ablation mechanism of the coatings was also investigated. The results show that the as-prepared coating is biphasic coating consisting of ZrC and TaC. The coating structure can be controlled by adjusting the deposition processing and the deposited coating exhibits multilayered-structure with columnar-crystal layer inserting between two particle-stacked layers. During ablation, the co-deposition coating exhibits outstanding configurational stability and good adhesion to substrate. After ablation for 60 s, the mass and linear ablation rates of the coated sample are 3.2′10?5 g/s and 5.3′10?5 mm/s, respectively, indicating that the coating has excellent ablation resistance properties.