ABSTRACT

In this research, the high-duration ablation resistance of SiC-gradient coating was investigated. SiC coating was prepared on graphite by reactive melt infiltration method at 1873 K under the argon atmosphere. Formation of the SiC layer with gradient distribution of Si and C elements was confirmed by X-ray diffraction patterns and scanning electron microscope micrographs. The results of the ablation test showed that SiC-graded coating with a proper adhesion could protect the graphite substrate up to 2073 K. The mass ablation rate for the SiC-graded coating after the 60 and 360 s ablation test under supersonic flame were −0.346 × 10⁻³ g/cm² s and −0.022 × 10⁻³ g/cm² s, respectively. The results indicated that the ablation mechanism of the SiC coating under supersonic flame is the SiO₂ scouring from the central ablation region to the outer ablation region in the layer by layer form.

摘要

在这项研究中，研究了 SiC 梯度涂层的高持续时间抗烧蚀性。在氩气气氛下，在 1873 K 的温度下，通过反应熔体渗透法在石墨上制备了 SiC 涂层。通过 X 射线衍射图和扫描电子显微镜显微照片证实了具有 Si 和 C 元素梯度分布的 SiC 层的形成。烧蚀试验结果表明，具有适当附着力的 SiC 梯度涂层可以保护石墨基体高达 2073 K。在超音速火焰下 60 和 360 s 烧蚀试验后，SiC 梯度涂层的质量烧蚀率为 -0.346 × 10 ^-3  g/cm ²  s 和 -0.022 × 10 ^-3  g/cm ² s，分别。结果表明，超音速火焰下SiC涂层的烧蚀机理为SiO ₂从中心烧蚀区向外部烧蚀区逐层冲刷。