C/C复合材料大气等离子喷涂mullite/ZrB2-MoSi2涂层抗烧蚀性能

Ablation Resistance of APS Sprayed Mullite/ZrB2-MoSi2 Coating for Carbon/Carbon Composites

摘要:

采用大气等离子喷涂技术(APS)在C/C复合材料表面制备了mullite/ZrB₂-MoSi₂双层抗烧蚀涂层。借助XRD、SEM、EDS等分析手段对涂层的组织结构进行研究；基于氧丙烯焰烧蚀试验考察ZrB₂-MoSi₂/mullite复合涂层对C/C复合材料高温耐烧蚀性能的影响。结果表明,在1700 °C和1800 °C的氧丙烯焰下烧蚀60 s,ZrB₂-MoSi₂/mullite涂层试样的质量烧蚀率分别为3.49×10_-3 g/s与3.77×10_-3 g/s。其与单层ZrB₂-MoSi₂涂层试样相比,ZrB₂-MoSi₂/mullite涂层试样展现了出色的抗烧蚀性能。烧蚀过程中形成的硅酸盐玻璃可以作为热障层而减少氧气的进一步渗透,并且还具有自我封填缺陷的能力,使ZrB₂-MoSi₂/mullite涂层表现较好的抗烧蚀性。

Abstract:

Mullite/ZrB₂-MoSi₂ coating was deposited on carbon/carbon(C/C) composites to protect against ablation by atmospheric plasma spraying (APS). The microstructure and morphology of the coating were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. The ablation resistance of the coating was investigated at different temperatures with oxypropylene torch. The mass ablation rates of the Mullite/ZrB₂-MoSi₂ coated C/C composites were 3.49×10_-3 g/s and 3.77×10_-3 g/s after ablation at 1700 °C and 1800 °C for 60 s respectively, which exhibited good ablation resistance compared with the single-layer ZrB₂-MoSi₂ coated. The increase of ablation resistance can be attributed to the formation of a silicates glass film, which acted as thermal barrier and self-sealed the defects of the coatings.