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采用化学气相沉积法(CVD)制备单质B和BC_x分别对SiC涂层进行改性,在二维碳纤维增强碳化硅(2D C/SiC)复合材料表面制备SiC/B/SiC和SiC/BC_x/SiC两种多层自愈合涂层,并利用扫描电镜对多层涂层表面和断面进行显微分析.700℃静态空气条件下氧化结果表明:CVD-B和CVD-BC_x改性层氧化后生成的B_2O_3玻璃相可以较好地封填涂层微裂纹,氧化动力学受氧通过微裂纹和B_2O_3玻璃层的扩散共同控制;SiC/BC_x/SiC-C/SiC复合材料氧化过程中氧化失重率更小,氧化10h后的强度保持率更高.
SiC / B / SiC and SiC / BC_x / SiC were prepared on the surface of 2D C / SiC composites by chemical vapor deposition (CVD) Two kinds of multi-layer self-healing coatings were obtained, and the surface and cross section of multi-layer coatings were analyzed by scanning electron microscopy. The results of oxidation at 700 ℃ in static air showed that the oxidation of CVD-B and CVD-BC_x layers B_2O_3 glassy phase can seal the microcracks well, and the oxidation kinetics is controlled by the microcracks and the diffusion of B 2 O 3 glass layer. The oxidative weight loss rate of the SiC / BC_x / SiC-C / SiC composites is more Small, higher intensity retention after oxidation 10h.