【摘要】 目的提高C/C-SiC复合材料的抗烧蚀性能。方法通过交联固化-碳化工艺获得新型含锆聚碳硅烷(Polyzirconocenecarbosilane, PZCS)裂解产物。采用FT-IR、XPS、TG、XRD、SEM等分析手段表征PZCS先驱体基本结构和固化、裂解产物结构及元素分布等。以PZCS为溶液浸渍先驱体,通过PIP工艺制备得到C/C-SiC-ZrC复合材料,采用氧乙炔烧蚀试验表征其抗烧蚀性能。结果 PZCS陶瓷先驱体经过交联固化工艺能够显著提高其陶瓷产率。TG结果表明,980℃时陶瓷产率达66.37%,所得陶瓷粉末为分散均匀的SiC-ZrC复相陶瓷。C/C-SiC-ZrC复合材料经过氧乙炔试验烧蚀600 s后,其线烧蚀率为0.0067 mm/s,表现出良好的抗烧蚀性能。结论 SiC-ZrC复相陶瓷基体烧蚀过程中,氧化形成SiO2和ZrO2等氧化物涂层,氧化物隔离层能够隔离氧气和热量,阻止其向复合材料内部进一步扩散,可有效提高复合材料烧蚀性能。更多还原

【Abstract】 Objective To improve the ablation property of C/C-SiC composites. Methods The novel polyzirconocenecarbosilane(PZCS) precursor was pyrolyzed through cross-linked and carbonization procedure. The structure, cross-linked, crystalline structure and element distribution of pyrolyzed ceramic of PZCS precursor were characterized by Fourier transform infrared spectroscopy(FT-IR), X-ray photoelectron spectroscopy(XPS), thermogravimetry(TG), X-ray diffraction(XRD) and scanning electron microscope(SEM). C/C-SiC-ZrC composite was prepared by precursor infiltration and pyrolysis with PZCS as a precursor. The ablation resistance property was characterized through oxyacetylene ablation test. Results It was obvious that the ceramic yield of PZCS precursor was improved after cross-lined and carbonization process. The TG result showed that the ceramic yield at 980 ℃ was about 66.37%, and the received ceramic was well-distributed ZrC-SiC multi-phase ceramic. After the C/C-SiC-ZrC composite was ablated by oxyacetylene flame for 600 s, its linear ablation was 0.0067 mm/s, showing very good anti-ablation performance. Conclusion The formation of ZrO2 and SiO2 layer during the ablation of SiC-ZrC multiphase ceramic matrix acted as an effective oxygen and heat barrier, preventing oxygen and heat from diffusing into composite, which could enhance its ablation property efficiently.更多还原