The thermal cyclic behavior of self-healing thermal barrier coatings (SH-TBC) is analyzed numerically to develop a lifetime prediction model. Representative microstructures are studied adopting a unit cell based multiscale modeling approach along with a simplified evolution model for the thermally-grown oxide layer (TGO) to study the evolution of damage and healing in a self-healing TBC system. The fracture and healing process is modeled using the cohesive zone-based healing model along with a crack tracking algorithm. The microstructural model includes splat boundaries and a wavy interface between the Top Coat and the Bond Coat, typical of Air Plasma Sprayed TBCs. A particle-based self-healing mechanism is accounted for with a random distribution of healing particles subjected to a numerically accelerated thermal cyclic loading condition. Lifetime extension of the self healing TBCs is quantified by conducting thermal cyclic analyses on conventional TBCs (benchmark system without self-healing particles). Parametric analyses on healing parameters such as crack filling ratio and strength recovery of the healed crack are also conducted. The results are presented in terms of the evolution of the crack pattern and the number of cycles to failure. For self-healing TBCs with a suitable healing reaction (i.e., cracks being partially filled and a minimal local strength after healing), an improvement in TBC lifetime is observed. In contrast, if the healing mechanism is not activated, the presence of the healing particles is actually detrimental to the lifetime of the TBC. Correspondingly, in addition to superior crack filling ratio and healed strength, significant improvement in lifetime is achieved for self healing TBCs with a higher probability of crack-healing particle interaction. This highlights the importance of a robust activation mechanism and a set of key material requirements in order to achieve successful self-healing of the TBC system.

通过对自修复热障涂层（SH-TBC）的热循环行为进行了数值分析，以建立寿命预测模型。研究了具有代表性的微观结构，采用了基于单位单元的多尺度建模方法以及热生长氧化物层（TGO）的简化演化模型，以研究自愈式TBC系统中损伤和愈合的演化。使用基于内聚区的愈合模型以及裂纹跟踪算法对骨折和愈合过程进行建模。微观结构模型包括splat边界和顶部涂层和粘结涂层之间的波浪形界面，这是空气等离子喷涂TBC的典型特征。基于粒子的自我修复机制是由于受到数值加速的热循环加载条件的愈合粒子的随机分布引起的。通过对常规TBC（没有自愈颗粒的基准系统）进行热循环分析，可以量化自愈TBC的使用寿命。还对愈合参数进行了参数分析，例如裂缝的填充率和已修复裂缝的强度恢复。结果以裂纹形式的演变和破坏的循环次数表示。对于具有适当愈合反应（即，裂缝被部分填充且愈合后的局部强度最小）的自愈合TBC，可以观察到TBC寿命的改善。相反，如果未激活愈合机制，则愈合颗粒的存在实际上对TBC的寿命有害。相应地，除了优异的裂纹填充率和愈合强度外，自我修复TBC的使用寿命得到了显着改善，裂纹修复颗粒相互作用的可能性更高。这凸显了强大的激活机制和一组关键材料要求的重要性，以实现TBC系统的成功自我修复。