Environmental barrier coatings (EBCs) protect SiC/SiC ceramic matrix composites from steam oxidation. Yb₂Si₂O₇ is a promising ceramic material for the top coating of the EBCs. However, thermal shock and foreign object debris can cause cracks on the surface of an EBC, thereby reducing its ability to overcome environmental barriers. It has been found that an EBC can be strengthened by adding SiC to its top coating; this addition heals the cracks present on the EBC when subjected to high-temperature oxidation. In this study, the SiC contents of Yb₂Si₂O₇ coatings prepared using atmospheric plasma spraying (APS) were evaluated to identify the structure and composition of the coatings. The results of crack-healing tests show that the Yb₂Si₂O₇/SiC granulated powder could retain SiC particles in the coatings after the spraying, whereas in Yb₂Si₂O₇/SiC mixed powder, the SiC particles evaporated during APS, indicating that Yb₂Si₂O₇/SiC granulated powder can be used as the feedstock powder in self-healing EBCs. The time-dependent changes in surface crack closure and Yb₂Si₂O₇/SiC granular powder coating remediation caused due to high-temperature oxidation were also evaluated. It was found that the reliability of self-healing EBCs could be improved by appropriately controlling the particle size and SiC content in the coatings.

环境屏障涂层 (EBC) 保护 SiC/SiC 陶瓷基复合材料免受蒸汽氧化。Yb ₂ Si ₂ O ₇是一种很有前途的用于EBC表面涂层的陶瓷材料。然而，热冲击和异物碎片会导致 EBC 表面出现裂缝，从而降低其克服环境障碍的能力。已经发现，可以通过在其顶部涂层中添加 SiC 来强化 EBC；这种添加可以修复EBC在高温氧化时出现的裂缝。_{在本研究中，Yb 2} Si ₂ O ₇的 SiC 含量对使用大气等离子喷涂 (APS) 制备的涂层进行了评估，以确定涂层的结构和组成。裂纹愈合试验结果表明，Yb ₂ Si ₂ O ₇ /SiC 粒状粉末在喷涂后可以将 SiC 颗粒保留在涂层中，而在 Yb ₂ Si ₂ O ₇ /SiC 混合粉末中，SiC 颗粒在 APS 过程中蒸发，表明Yb ₂ Si ₂ O ₇ /SiC颗粒粉末可作为自愈EBCs的原料粉末。_{表面裂纹闭合和 Yb 2} Si ₂ O ₇的随时间变化还评估了由于高温氧化引起的/SiC颗粒粉末涂层的修复。研究发现，通过适当控制涂层中的粒径和 SiC 含量，可以提高自愈 EBC 的可靠性。