目的 更好地理解热障涂层在热循环条件下的失效行为。方法 采用有限元方法引入了内聚力模型，研究热障涂层在多次热循环条件下的界面开裂行为，并且考虑了陶瓷层厚度和粘结层厚度对界面开裂行为的影响。结果 涂层最先在陶瓷层/TGO层界面的波峰与波谷之间开裂，此外在界面波谷处也存在开裂现象。当陶瓷层厚度在300~500 μm范围内，界面裂纹的平均长度随陶瓷层增厚而增长，裂纹密度也随之增加。粘结层厚度为50 μm时，界面裂纹的平均长度为15 μm；当厚度增加到100 μm时，界面裂纹平均长度减少到10 μm；而厚度为150 μm时，界面裂纹平均长度又提高至12 μm。当粘结层与陶瓷层厚度比在0.2~0.4的范围内时，陶瓷层/TGO层界面上的最大拉应力最小。结论 陶瓷层厚度和粘结层厚度对热障涂层界面开裂行为的影响极大，小厚度陶瓷层以及当粘结层与陶瓷层厚度比在0.2~0.4的范围内时，热障涂层具有更好的抗界面开裂能力。粘结层厚度不宜过大，超过一定厚度时反而会降低涂层的抗界面开裂能力。计算结果与文献报道的结果相近，证明了模拟结果的准确性。

The work aims to better understand failure behavior of thermal barrier coating in thermal cycles. Interfacial crack behavior of thermal barrier coating during multiple thermal cycles was studied by introducing cohesive zone model in finite element method. And the effects of ceramic layer thickness and bonding layer thickness on interfacial crack behavior were taken into consideration as well. Crack was first present between crest and trough of ceramic layer/TGO layer interface. Crack was present in trough of the interface. Both average crack length and density increased as the ceramic layer thickness increased as the ceramic layer thickness ranged from 300 μm to 500 μm. The average crack length was 15 μm when the bonding layer was 50 μm thick; it decreased to 10 μm when the bonding layer was 100 μm thick; and increased to 12 μm when the bonding layer was 150 μm thick. The maximum tension stress on ceramic layer/TGO layer interface was the minimum when thickness ratio of the ceramic layer and bonding layer ranged from 0.2 to 0.4, hence the thermal barrier coating had better interfacial crack resistance. The interfacial crack behavior is greatly affected by thickness of ceramic layer and bonding layer, and the interfacial crack resistance will be reduced when the bonding layer is too thick. The calculation results are close that those reported in the literatures, which confirms the accuracy of simulation results.