研究了复合材料表面 CVD Si C涂层的制备工艺 ,并对涂层的表面致密化性能进行分析。在不同的工艺条件下制备 Si C涂层 ,探讨了温度、载气流速、时间等因素对涂层的影响。利用扫描电镜和 X-射线衍射仪 ,对涂层晶型进行分析 ,讨论不同条件...研究了复合材料表面 CVD Si C涂层的制备工艺 ,并对涂层的表面致密化性能进行分析。在不同的工艺条件下制备 Si C涂层 ,探讨了温度、载气流速、时间等因素对涂层的影响。利用扫描电镜和 X-射线衍射仪 ,对涂层晶型进行分析 ,讨论不同条件下 Si C的结晶形态 ,从而得出制备致密涂层的较好工艺。展开更多
In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simula...In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simulated atomic oxygen(AO) generator was employed. Results indicate that the CVD SiC coating exhibited improved radiation resistance properties against AO radiation as evidenced by a 16%better strength retention ratio, 60% less mass ablation, and increased strength stability. The magnitude of these influences affected the surface morphology, as observed by scanning electron microscopy(SEM)and surface resistance meter test results. The variations in the surface constituents were confirmed by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) results. The main products left on surface after AO exposure are SiO2 and SiCxOyfilm. Additionally, Si atoms are found to be the preferential reacting element in the SiC coating, and this process is accompanied by graphite precipitation, grain growth, and crack necking. Also, the damage mechanism of the AO-exposed SiC coating was revealed and is discussed.展开更多
文摘研究了复合材料表面 CVD Si C涂层的制备工艺 ,并对涂层的表面致密化性能进行分析。在不同的工艺条件下制备 Si C涂层 ,探讨了温度、载气流速、时间等因素对涂层的影响。利用扫描电镜和 X-射线衍射仪 ,对涂层晶型进行分析 ,讨论不同条件下 Si C的结晶形态 ,从而得出制备致密涂层的较好工艺。
基金funded by the National Natural Science Foundation of China (Nos. 51632007 and No. 51672218 and No. 51821091)the National Key R&D Program of China (Grant No.2017YFB1103500)
文摘In this work, samples of carbon/carbon(C/C) and chemical vapor deposited(CVD) SiC-coated C/C samples were investigated to understand the AO damage mechanism in low Earth orbit(LEO) environment. The ground-based simulated atomic oxygen(AO) generator was employed. Results indicate that the CVD SiC coating exhibited improved radiation resistance properties against AO radiation as evidenced by a 16%better strength retention ratio, 60% less mass ablation, and increased strength stability. The magnitude of these influences affected the surface morphology, as observed by scanning electron microscopy(SEM)and surface resistance meter test results. The variations in the surface constituents were confirmed by X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS) results. The main products left on surface after AO exposure are SiO2 and SiCxOyfilm. Additionally, Si atoms are found to be the preferential reacting element in the SiC coating, and this process is accompanied by graphite precipitation, grain growth, and crack necking. Also, the damage mechanism of the AO-exposed SiC coating was revealed and is discussed.
